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how do electric forces work ? electric forces are responsible for almost every single chemical reaction that occurs in your body . almost all of biochemistry relies on understanding how these forces cause electrons to move between atoms , and the changes in the structure or composition that occur when electrons move be... | the plates are working together to make the imaginary particle move toward the right . what is electric potential energy ? electric potential energy is the energy that is needed to move a charge against an electric field . | is potential energy just a scalar quantity and you can add potential energies due to different plates or is it scalar ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | for a typical human cell , however , proteins account for about 50 percent of the composition by mass , lipids ( of all types ) account for about 40 percent , and the remaining 10 percent comes from carbohydrates . phospholipids phospholipids , arranged in a bilayer , make up the basic fabric of the plasma membrane . t... | how do phospholipids affect the permeability of the membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | a phospholipid is a lipid made of glycerol , two fatty acid tails , and a phosphate-linked head group . biological membranes usually involve two layers of phospholipids with their tails pointing inward , an arrangement called a phospholipid bilayer . cholesterol , another lipid composed of four fused carbon rings , is ... | what is between the phospholipid bilayer ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane proteins do not stick into the hydrophobic core of the membrane , and they tend to be more loosely attached . carboh... | why do we have proteins in the cell membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | here , we ’ ll take a closer look at the different components of the plasma membrane , examining their roles , their diversity , and how they work together to make a flexible , sensitive , and secure boundary around the cell . fluid mosaic model the currently accepted model for the structure of the plasma membrane , ca... | fluid mosaic model is cell of ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . luckily , the plasma membrane turns out to be very well-suited to its job , sala... | as in why do n't sharp objects like pins and needles go straight through ( i know it sounds silly ) our skin without drawing blood ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | biological membranes usually involve two layers of phospholipids with their tails pointing inward , an arrangement called a phospholipid bilayer . cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into th... | these rings control the fluidity of the membrane like cholesterol does ... but why are chain forms of isoprene more commonly found in archeas living in hot environments ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | along with membrane proteins , these carbohydrates form distinctive cellular markers , sort of like molecular id badges , that allow cells to recognize each other . these markers are very important in the immune system , allowing immune cells to differentiate between body cells , which they shouldn ’ t attack , and for... | how does cells deal with osmotic pressure ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins , forming glycoproteins , or lipids , forming glycolipids . t... | are glycoproteins a kind of protein or a kind of carbohydrate ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on th... | which type of protein penetrates to the interior of the plasma membrane but does not extend all the way through it ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | most cell membranes contain a mixture of phospholipids , some with two saturated ( straight ) tails and others with one saturated and one unsaturated ( bent ) tail . many organisms—fish are one example—can adjust physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membran... | can you give an example of how internal membranes facilitate simultaneous occurrence of diverse cellular processes ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | along with membrane proteins , these carbohydrates form distinctive cellular markers , sort of like molecular id badges , that allow cells to recognize each other . these markers are very important in the immune system , allowing immune cells to differentiate between body cells , which they shouldn ’ t attack , and for... | whats the different roles of membranes within cells and at the surface of cells ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | what exactly is its job ? the plasma membrane not only defines the borders of the cell , but also allows the cell to interact with its environment in a controlled way . cells must be able to exclude , take in , and excrete various substances , all in specific amounts . | what is the point of glycolipids in a cell ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | the hydrophobic , or “ water-fearing , ” part of a phospholipid consists of its long , nonpolar fatty acid tails . the fatty acid tails can easily interact with other nonpolar molecules , but they interact poorly with water . because of this , it ’ s more energetically favorable for the phospholipids to tuck their fatt... | how dose the membrane interact with water ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane proteins do not stick into the hydrophobic core of the membrane , and they tend to be more loosely attached . carboh... | what 's the role of a peripheral membrane protein ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins , forming glycoproteins , or lipids , forming glycolipids . t... | what are the functions of glycolipids and glycoproteins ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | some integral membrane proteins form a channel that allows ions or other small molecules to pass , as shown below . peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane ... | why are there strands of carbohydrates and proteins attached to the outside ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | most cell membranes contain a mixture of phospholipids , some with two saturated ( straight ) tails and others with one saturated and one unsaturated ( bent ) tail . many organisms—fish are one example—can adjust physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membran... | also , is there any region of a human body that is more likely to develop unsaturated fatty acids than another part ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | for more information about saturated and unsaturated fatty acids , see the article on lipids . in addition to phospholipids , animals have an additional membrane component that helps to maintain fluidity . cholesterol , another type of lipid that is embedded among the phospholipids of the membrane , helps to minimize t... | since cholesterol helps maintain the fluidity of a cell , how does having high cholesterol effect the cell ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on th... | i know this was previously asked but i just wanted a more in depth explanation of how the membrane acts as a selective barrier in determining which substances can pass through ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | proteins proteins are the second major component of plasma membranes . there are two main categories of membrane proteins : integral and peripheral . integral membrane proteins are , as their name suggests , integrated into the membrane : they have at least one hydrophobic region that anchors them to the hydrophobic co... | in examining the constituents of the plasma membrane of two individual people , which of the following constituents would probably show the greatest difference between the two : phospholipid , protein , glycoprotein , or cholesterol ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | the fatty acid tails can easily interact with other nonpolar molecules , but they interact poorly with water . because of this , it ’ s more energetically favorable for the phospholipids to tuck their fatty acid tails away in the interior of the membrane , where they are shielded from the surrounding water . the phosph... | what does 'energetically favorable ' means ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | what exactly is its job ? the plasma membrane not only defines the borders of the cell , but also allows the cell to interact with its environment in a controlled way . cells must be able to exclude , take in , and excrete various substances , all in specific amounts . | do glycoproteins always stay attached to the cell and branch out , or can they also branch in towards the cell ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | along with membrane proteins , these carbohydrates form distinctive cellular markers , sort of like molecular id badges , that allow cells to recognize each other . these markers are very important in the immune system , allowing immune cells to differentiate between body cells , which they shouldn ’ t attack , and for... | what do the palisade and spongy mesophyll cells have in common ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | in addition , they must able to communicate with other cells , identifying themselves and sharing information . to perform these roles , the plasma membrane needs lipids , which make a semi-permeable barrier between the cell and its environment . it also needs proteins , which are involved in cross-membrane transport a... | how does the structure of the cell membrane account for the semi-permeable nature ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | ( you can see an example of a bent , unsaturated tail in the diagram of phospholipid structure that appears earlier in this article . ) the saturated and unsaturated fatty acid tails of phospholipids behave differently as temperature drops : at cooler temperatures , the straight tails of saturated fatty acids can pack ... | thanks and which fatty acids are present abundantly in membrane p.lipid ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on th... | how do cells communicate with each other through the plasma membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | if the phospholipids have small tails , they may form a micelle ( a small , single-layered sphere ) , while if they have bulkier tails , they may form a liposome ( a hollow droplet of bilayer membrane ) $ ^2 $ . proteins proteins are the second major component of plasma membranes . there are two main categories of memb... | what purpose do peripheral proteins serve ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane proteins do not stick into the hydrophobic core of the membrane , and they tend to be more loosely attached . carboh... | in that case why does it stay within the hydrophobic part of the membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | some stick only partway into the membrane , while others stretch from one side of the membrane to the other and are exposed on either side $ ^1 $ . proteins that extend all the way across the membrane are called transmembrane proteins . the portions of an integral membrane protein found inside the membrane are hydropho... | can transmembrane proteins enter the lipid bilayer spontaneously or is the process facilitated by other proteins ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | transmembrane proteins may cross the membrane just once , or may have as many as twelve different membrane-spanning sections . a typical membrane-spanning segment consists of 20-25 hydrophobic amino acids arranged in an alpha helix , although not all transmembrane proteins fit this model . some integral membrane protei... | what 's an alpha helix ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | a typical membrane-spanning segment consists of 20-25 hydrophobic amino acids arranged in an alpha helix , although not all transmembrane proteins fit this model . some integral membrane proteins form a channel that allows ions or other small molecules to pass , as shown below . peripheral membrane proteins are found o... | why is the size of phospholipid molecules so small ( in nanometers ) ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | a phospholipid is a lipid made of glycerol , two fatty acid tails , and a phosphate-linked head group . biological membranes usually involve two layers of phospholipids with their tails pointing inward , an arrangement called a phospholipid bilayer . cholesterol , another lipid composed of four fused carbon rings , is ... | what materials can pass through the phospholipid bilayer by passive transport ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | biological membranes usually involve two layers of phospholipids with their tails pointing inward , an arrangement called a phospholipid bilayer . cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into th... | why is cholesterol not found in the membrane of plant cells ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | instead , this is something they ’ ll do spontaneously under the right conditions ! in water or aqueous solution , phospholipids tend to arrange themselves with their hydrophobic tails facing each other and their hydrophilic heads facing out . if the phospholipids have small tails , they may form a micelle ( a small , ... | how comes the hydrophilic heads outside allow non polar substances to pass through them if the hydrophobic tails inside do no allow water to go through them ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | if the phospholipids have small tails , they may form a micelle ( a small , single-layered sphere ) , while if they have bulkier tails , they may form a liposome ( a hollow droplet of bilayer membrane ) $ ^2 $ . proteins proteins are the second major component of plasma membranes . there are two main categories of memb... | how are proteins the second major component of plasma membranes ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | in other words , a diagram of the membrane ( like the one below ) is just a snapshot of a dynamic process in which phospholipids and proteins are continually sliding past one another . interestingly enough , this fluidity means that if you insert a very fine needle into a cell , the membrane will simply part to flow ar... | what would be the resulting net flow of sucrose ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins , forming glycoproteins , or lipids , forming glycolipids . the proportions of proteins , lipids , and carbohydrates in the plasma membrane vary between different types of cells . for a typical human cell , how... | why might the protein : lipid ratio vary between different cell types ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | a phospholipid is a lipid made of glycerol , two fatty acid tails , and a phosphate-linked head group . biological membranes usually involve two layers of phospholipids with their tails pointing inward , an arrangement called a phospholipid bilayer . cholesterol , another lipid composed of four fused carbon rings , is ... | what does a phospholipid bilayer do ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | the hydrophilic , or “ water-loving , ” portion of a phospholipid is its head , which contains a negatively charged phosphate group as well as an additional small group ( of varying identity , “ r ” in the diagram at left ) , which may also or be charged or polar . the hydrophilic heads of phospholipids in a membrane b... | how can the head of phospholipid be attracted to water outside the cell , if it 's part of the cell ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on th... | 2 second question is , what happens if you break the cell membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | transmembrane proteins may cross the membrane just once , or may have as many as twelve different membrane-spanning sections . a typical membrane-spanning segment consists of 20-25 hydrophobic amino acids arranged in an alpha helix , although not all transmembrane proteins fit this model . some integral membrane protei... | what is the function of the alpha-helix protein ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | most cell membranes contain a mixture of phospholipids , some with two saturated ( straight ) tails and others with one saturated and one unsaturated ( bent ) tail . many organisms—fish are one example—can adjust physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membran... | can a phospholipid have two unsaturated fatty acids ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | there are two main categories of membrane proteins : integral and peripheral . integral membrane proteins are , as their name suggests , integrated into the membrane : they have at least one hydrophobic region that anchors them to the hydrophobic core of the phospholipid bilayer . some stick only partway into the membr... | does all cell membrane have bilayer phospholipid ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | the hydrophilic heads of phospholipids in a membrane bilayer face outward , contacting the aqueous ( watery ) fluid both inside and outside the cell . since water is a polar molecule , it readily forms electrostatic ( charge-based ) interactions with the phospholipid heads . the hydrophobic , or “ water-fearing , ” par... | of yes then how does micelle forms because it has only one layer phospholipid ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane proteins do not stick into the hydrophobic core of the membrane , and they tend to be more loosely attached . carboh... | thats proteins are of the plama membrane or of the cell membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | peripheral membrane proteins are found on the outside and inside surfaces of membranes , attached either to integral proteins or to phospholipids . unlike integral membrane proteins , peripheral membrane proteins do not stick into the hydrophobic core of the membrane , and they tend to be more loosely attached . carboh... | why do proteins need to be embedded in the cell membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . | what is a `` protein channel '' in the first pic ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | for more information about saturated and unsaturated fatty acids , see the article on lipids . in addition to phospholipids , animals have an additional membrane component that helps to maintain fluidity . cholesterol , another type of lipid that is embedded among the phospholipids of the membrane , helps to minimize t... | if cholesterol helps cells maintain integrity , is there a point where a cell has access to too much cholesterol ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | along with membrane proteins , these carbohydrates form distinctive cellular markers , sort of like molecular id badges , that allow cells to recognize each other . these markers are very important in the immune system , allowing immune cells to differentiate between body cells , which they shouldn ’ t attack , and for... | i know it can build up in the bloodstream and clog arteries , but does it have similar negative effects when it builds up on cells ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | cholesterol , another lipid composed of four fused carbon rings , is found alongside phospholipids in the core of the membrane . membrane proteins may extend partway into the plasma membrane , cross the membrane entirely , or be loosely attached to its inside or outside face . carbohydrate groups are present only on th... | what 's the difference between the cell membrane and plasma membrane ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | phospholipids with unsaturated fatty acid tails can not pack together as tightly because of the bent structure of the tails . because of this , a membrane containing unsaturated phospholipids will stay fluid at lower temperatures than a membrane made of saturated ones . most cell membranes contain a mixture of phosphol... | would a more tightly packed , saturated membrane be considered more stable than an unsaturated one ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | most cell membranes contain a mixture of phospholipids , some with two saturated ( straight ) tails and others with one saturated and one unsaturated ( bent ) tail . many organisms—fish are one example—can adjust physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membran... | how does the structure of both unsaturated fatty acids and cholesterol fit their function as temperature regulators ? |
introduction each cell of your body is encased in a tiny bubble of membrane . this membrane has about the consistency of ... salad oil $ ^1 $ . the first time i read that factoid , i did n't find it very reassuring ! salad oil seems like an awfully fragile boundary to place between a cell and the rest of the world . lu... | most cell membranes contain a mixture of phospholipids , some with two saturated ( straight ) tails and others with one saturated and one unsaturated ( bent ) tail . many organisms—fish are one example—can adjust physiologically to cold environments by changing the proportion of unsaturated fatty acids in their membran... | do humans adapted to cold environments have a higher proportion unsaturated fatty acid chains in the membranes of their cells ( which would keep membranes fluid at lower temperatures ) ? |
alabama , arizona , arkansas , connecticut , illinois , iowa , kansas , kentucky , massachusetts , minnesota , mississippi , missouri , the dakotas , ohio , oklahoma , oregon , utah , wisconsin , wyoming—all state names derived from native american sources . pontiac , moose , raccoon , pecan , kayak , squash , chipmunk... | other terms are equally problematic or generic . you might encounter many different terms to describe the peoples in north america , such as native american , american indian , amerindian , aboriginal , native , indigenous , first nations , and first peoples . native american is used here because people are most famili... | what evidence do we have that the native americans came to the americas via boat ? |
alabama , arizona , arkansas , connecticut , illinois , iowa , kansas , kentucky , massachusetts , minnesota , mississippi , missouri , the dakotas , ohio , oklahoma , oregon , utah , wisconsin , wyoming—all state names derived from native american sources . pontiac , moose , raccoon , pecan , kayak , squash , chipmunk... | in the past , the navajo term “ anasazi ” was used to name the ancestors of modern-day puebloans . today , “ ancestral puebloans ” is considered more acceptable . likewise , “ eskimo ” designated peoples in the arctic region , but this word has fallen out of favor because it homogenizes the first nations in this area . | in the last paragraph , what is puebloans ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | this art was perceived to be more honest and direct , more natural than work produced by artists from industrialized western european nations . there was also interest in the so-called “ folk art ” of europe , particularly the art and craft found among rural populations . it is important to note that germany remained a... | my question to the khan community is expressionism telling more truth than realistic or naturalism art style , or the art movements prior to expressionism ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | in addition , more than 600 of his works were removed from public collections . he committed suicide in 1938 . essay by shawn roggenkamp additional resources : this painting at the allen memorial art museum a biography of the artist from oxford university press at moma | why did kirchner commit suicide ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | in addition , more than 600 of his works were removed from public collections . he committed suicide in 1938 . essay by shawn roggenkamp additional resources : this painting at the allen memorial art museum a biography of the artist from oxford university press at moma | why did kirchner commit suicide ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . | what is kirchner trying to portray self-portrait as a soldier ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | paintings created outside , in nature , together with the unidealized nudes were hallmarks of the group ’ s work . the roughly sketched , long forms and tapered limbs of the nude model in self-portrait as a soldier is representative of the style of kirchner ’ s nudes from this period and can be seen in his prints as we... | what is the point of a nude person in the background of as a soldier ? |
ernst ludwig kirchner ’ s self-portrait as a soldier is a masterpiece of psychological drama . the painting shows kirchner dressed in a uniform but instead of standing on a battlefield ( or another military context ) , he is standing in his studio with an amputated , bloody arm and a nude model behind him . it is in th... | compare that with the sallow , angular artist we see in the self-portrait as a soldier . the later painting features darker , colder colors , and the glassy-eyed model looks more like a carved statue than an actual person . even the skinny , limp cigarette seems to stand in opposition to the robust pipe that the artist... | why does the naked man looks like a woman body ? |
at the breath-taking elevation of 11,200 feet ( roughly 3,400 m ) , the city of cusco was not just the capital of tawantinsuyu ( “ land of the four quarters , ” the inka name for their empire in their native language , quechua ) . it was an axis mundi—the center of existence—and a reflection of inka power . the city wa... | but the spectacular , radiant exterior was not the apex of the building ’ s wonders . inside , a reproduction of the world in miniature took the shape of a garden made from gold , silver and jewels , with people , animals , and plants . the riches of the qorikancha would be taken in the looting of the city following th... | what do you mean by `` took the shape of a garden made from gold , silver , and jewels , with people , animals , and plants '' in the last paragraph of the qorikancha section ? |
at the breath-taking elevation of 11,200 feet ( roughly 3,400 m ) , the city of cusco was not just the capital of tawantinsuyu ( “ land of the four quarters , ” the inka name for their empire in their native language , quechua ) . it was an axis mundi—the center of existence—and a reflection of inka power . the city wa... | all of the doorways , windows , and wall niches of the qorikancha were the distinctive inka trapezoid shape , with doorways double-jambed ( see image below ) to signify the importance of the building . the exceptionally fine masonry of the qorikancha was reserved for the most important buildings , since it was even mor... | what country are these buildings in ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | on the basis of this fraction , the age of the material can be calculated with accuracy if it is not much older than about 50,000 years . other elements have isotopes with different half lives , and can thus be used to measure age on different timescales . for example , potassium-40 has a half-life of 1.25 billion year... | is there any simplest explanation about how half-life of an isotope can be used to determine the age of fossils ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | other elements have isotopes with different half lives , and can thus be used to measure age on different timescales . for example , potassium-40 has a half-life of 1.25 billion years , and uranium-235 has a half-life of about 700 million years and has been used to measure the age of moon rocks $ ^2 $ . | how is the 1/2 life of an atom determined ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | radioactive decay can cause a change in the number of protons in the nucleus ; when this happens , the identity of the atom changes ( e.g. , carbon-14 decaying to nitrogen-14 ) . radioactive decay is a random but exponential process , and an isotope ’ s half-life is the period over which half of the material will decay... | why do we measure radioactive decay by half-life , not its whole life ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | these different versions of elements are called isotopes , and small quantities of radioactive isotopes often occur in nature . for instance , a small amount of carbon exists in the atmosphere as radioactive carbon-14 , and the amount of carbon-14 found in fossils allows paleontologists to determine their age . in this... | so just to clarify , this means that the older the fossil , the lower the amount of carbon-14 present ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | in general , though , an atom 's atomic mass will be very close to its mass number , but will have some deviation in the decimal places . since an element ’ s isotopes have different atomic masses , scientists may also determine the relative atomic mass—sometimes called the atomic weight—for an element . the relative a... | so for radiometric rating to work , you have to assume that the element has been decaying at the same rate the entire time ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | forms of the same atom that differ only in their number of neutrons are called isotopes . together , the number of protons and the number of neutrons determine an element ’ s mass number : mass number = protons + neutrons . if you want to calculate how many neutrons an atom has , you can simply subtract the number of p... | why element with low mass usually have same number of protons and neutrons in their atom ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | this property can be used to date formerly living objects such as old bones or wood . by comparing the ratio of carbon-14 to carbon-12 concentrations in an object to the same ratio in the atmosphere , equivalent to the starting concentration for the object , the fraction of the isotope that has not yet decayed can be d... | can we imagine a future when it will be completely decayed and wiped out from this universe ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | in this article , we ’ ll look in more detail at the subatomic particles that different atoms contain as well as what makes an isotope radioactive . atomic number , atomic mass , and relative atomic mass atoms of each element contain a characteristic number of protons . in fact , the number of protons determines what a... | but if you are only given the atomic number is it possible to find out what the atomic mass is ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | the ratio of the original isotope to its decay product and to stable isotopes changes in a predictable way ; this predictability allows the relative abundance of the isotope to be used as a clock that measures the time from the incorporation of the isotope ( e.g. , into a fossil ) to the present . for example , carbon ... | during radioactive decay , for example , has a carbon 14 atom morphed into a carbon 13 atom to become more stable by simply kicking out a neutron ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | like with what we mesure if carbon- 14 , potassium-40 and uranium-235 concentration test fails ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | the ratio of the original isotope to its decay product and to stable isotopes changes in a predictable way ; this predictability allows the relative abundance of the isotope to be used as a clock that measures the time from the incorporation of the isotope ( e.g. , into a fossil ) to the present . for example , carbon ... | and one more question : how accurate those carbon dating is ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | often , elements come in both radioactive and nonradioactive versions that differ in the number of neutrons they contain . these different versions of elements are called isotopes , and small quantities of radioactive isotopes often occur in nature . for instance , a small amount of carbon exists in the atmosphere as r... | can the fossils be infested whit those isotopes when the test is made ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | how is possible carbon 14 atom convert to nitrogen 14 gradually ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as carbon-14 decays gradually to nitrogen-14 $ ^2 $ . after a half-life of approximately 5,730 years , half of the carbon-14 that was initially present will have been co... | so when someone says they carbon date a fossil and say it is 1 billion years old , because c-14 has a half-life of 5,730 years , they used k-40 and not c-14 ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | why is carbon 14 sometimes radioactive ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | isotopes and radioactive decay as mentioned above , isotopes are different forms of an element that have the same number of protons but different numbers of neutrons . many elements—such as carbon , potassium , and uranium—have multiple naturally occurring isotopes . carbon-12 contains six protons , six neutrons , and ... | also how do you know how many electrons that the elements starts with ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | why not measure the ratio of carbon-14 to nitrogen-14 in a sample when using radiometric ( carbon ) dating ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | radioactivity is actually a property of an atom . radioactive atoms have unstable nuclei , and they will eventually release subatomic particles to become more stable , giving off energy—radiation—in the process . often , elements come in both radioactive and nonradioactive versions that differ in the number of neutrons... | if there was a nuclear explosion , what would make the particles ( of the atomes ) radioactive ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | radioactivity is actually a property of an atom . radioactive atoms have unstable nuclei , and they will eventually release subatomic particles to become more stable , giving off energy—radiation—in the process . often , elements come in both radioactive and nonradioactive versions that differ in the number of neutrons... | how long does a subatomic particle last without it disappearing or disintegrating or whatever happens to a subatomic particle when its life ends ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | in general , though , an atom 's atomic mass will be very close to its mass number , but will have some deviation in the decimal places . since an element ’ s isotopes have different atomic masses , scientists may also determine the relative atomic mass—sometimes called the atomic weight—for an element . the relative a... | in the 6th paragraph , about calculating relative atomic mass , how can scientists know exactly how much of one isotope exists on earth in proportion to other isotopes ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | other elements have isotopes with different half lives , and can thus be used to measure age on different timescales . for example , potassium-40 has a half-life of 1.25 billion years , and uranium-235 has a half-life of about 700 million years and has been used to measure the age of moon rocks $ ^2 $ . | above , you say that `` potassium-40 has a half life of 1.25 billion years , but how do you know that to be true ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | for instance , a small amount of carbon exists in the atmosphere as radioactive carbon-14 , and the amount of carbon-14 found in fossils allows paleontologists to determine their age . in this article , we ’ ll look in more detail at the subatomic particles that different atoms contain as well as what makes an isotope ... | do atoms ever really `` die '' ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | on the basis of this fraction , the age of the material can be calculated with accuracy if it is not much older than about 50,000 years . other elements have isotopes with different half lives , and can thus be used to measure age on different timescales . for example , potassium-40 has a half-life of 1.25 billion year... | humans have not been around long enough to measure the half life of these radioactive isotopes , so my question is how ... ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | other elements have isotopes with different half lives , and can thus be used to measure age on different timescales . for example , potassium-40 has a half-life of 1.25 billion years , and uranium-235 has a half-life of about 700 million years and has been used to measure the age of moon rocks $ ^2 $ . | how do we know that uranium-235 has a half-life of 700 millions years ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | such isotopes are called radioisotopes , and the process in which they release particles and energy is known as decay . radioactive decay can cause a change in the number of protons in the nucleus ; when this happens , the identity of the atom changes ( e.g. , carbon-14 decaying to nitrogen-14 ) . radioactive decay is ... | during radioactive decay , can the neutron be kicked out of the nucleus ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | just to be clear carbon 14 comes from rotting or decaying organisims , right ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | carbon-14 decaying to nitrogen-14 '' - does n't that mean it will have to 'gain ' a proton in order to become nitrogen ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as carbon-14 decays gradually to nitrogen-14 $ ^2 $ . after a half-life of approximately 5,730 years , half of the carbon-14 that was initially present will have been co... | how would one properly understand what a half life is ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | atomic number , atomic mass , and relative atomic mass atoms of each element contain a characteristic number of protons . in fact , the number of protons determines what atom we are looking at ( e.g. , all atoms with six protons are carbon atoms ) ; the number of protons in an atom is called the atomic number . in cont... | in an atom are there the same number of protons as electrons ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | atomic number , atomic mass , and relative atomic mass atoms of each element contain a characteristic number of protons . in fact , the number of protons determines what atom we are looking at ( e.g. , all atoms with six protons are carbon atoms ) ; the number of protons in an atom is called the atomic number . in cont... | can an atom ever have a disproportionate amount of protons and electrons ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | the relative atomic masses given in periodic table entries—like the one for hydrogen , below—are calculated for all the naturally occurring isotopes of each element , weighted by the abundance of those isotopes on earth . extraterrestrial objects , like asteroids or meteors , might have very different isotope abundance... | maybe i missed something , but if isotopes are atoms that differ in the amount of neutrons from protons , how is carbon-12 an isotope ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | the ratio of the original isotope to its decay product and to stable isotopes changes in a predictable way ; this predictability allows the relative abundance of the isotope to be used as a clock that measures the time from the incorporation of the isotope ( e.g. , into a fossil ) to the present . for example , carbon ... | i do n't get this question : why do the three abundant isotopes of carbon all form the same types of chemical bonds ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | these different versions of elements are called isotopes , and small quantities of radioactive isotopes often occur in nature . for instance , a small amount of carbon exists in the atmosphere as radioactive carbon-14 , and the amount of carbon-14 found in fossils allows paleontologists to determine their age . in this... | so the amount of carbon 14 in the atmosphere has n't or ca n't be changed ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | as animals eat the plants , or eat other animals that ate plants , the concentrations of carbon-14 in their bodies will also match the atmospheric concentration . when an organism dies , it stops taking in carbon-14 , so the ratio of carbon-14 to carbon-12 in its remains , such as fossilized bones , will decline as car... | does the possibility of having too much carbon-14 in our atmosphere exist ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | radioactive decay is a random but exponential process , and an isotope ’ s half-life is the period over which half of the material will decay to a different , relatively stable product . the ratio of the original isotope to its decay product and to stable isotopes changes in a predictable way ; this predictability allo... | how do scientists work out the relative abundance of each isotope ? |
introduction radioactivity pops up fairly often in the news . for instance , you might have read about it in discussions of nuclear energy , the fukushima reactor tragedy , or the development of nuclear weapons . it also shows up in popular culture : many superheroes ’ origin stories involve radiation exposure , for in... | in this article , we ’ ll look in more detail at the subatomic particles that different atoms contain as well as what makes an isotope radioactive . atomic number , atomic mass , and relative atomic mass atoms of each element contain a characteristic number of protons . in fact , the number of protons determines what a... | if an element has an atomic number of 12 how many electrons are in it 's outermost shell ? |
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