context
stringlengths
545
71.9k
questionsrc
stringlengths
16
10.2k
question
stringlengths
11
563
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
an rna transcript that is ready to be used in translation is called a messenger rna ( mrna ) . in bacteria , rna transcripts are ready to be translated right after transcription . in fact , they 're actually ready a little sooner than that : translation may start while transcription is still going on !
what modifications occur to initially transcribed rna right before it gets translated ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
when it catches up with the polymerase at the transcription bubble , rho pulls the rna transcript and the template dna strand apart , releasing the rna molecule and ending transcription . another sequence found later in the dna , called the transcription stop point , causes rna polymerase to pause and thus helps rho ca...
how rna polymerase spontaneously detaches from dna template in rho independent termination ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
if the gene that 's transcribed encodes a protein ( which many genes do ) , the rna molecule will be read to make a protein in a process called translation . rna polymerase rna polymerases are enzymes that transcribe dna into rna . using a dna template , rna polymerase builds a new rna molecule through base pairing .
what causes rna polymerase to detach ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) .
if rna polymerase is in the origin of the transcription , and it has also to be transcript , how has it appear in the cell ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
for instance , if there is a g in the dna template , rna polymerase will add a c to the new , growing rna strand . rna polymerase always builds a new rna strand in the 5 ’ to 3 ’ direction . that is , it can only add rna nucleotides ( a , u , c , or g ) to the 3 ' end of the strand .
i thought rna polymerase runs in the 5 ' to 3 ' direction , as mentioned in your ''overview of transcription '' article ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
the process of ending transcription is called termination , and it happens once the polymerase transcribes a sequence of dna known as a terminator . termination in bacteria there are two major termination strategies found in bacteria : rho-dependent and rho-independent . in rho-dependent termination , the rna contains ...
why does there exist a need for two separate mechanisms for termination in bacteria ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
the picture is different in the cells of humans and other eukaryotes . that 's because transcription happens in the nucleus of human cells , while translation happens in the cytosol . also , in eukaryotes , rna molecules need to go through special processing steps before translation .
what happens do the dna after the transcription it 's done ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
let 's take a closer look at what happens during transcription . transcription overview transcription is the first step of gene expression . during this process , the dna sequence of a gene is copied into rna .
molecule of dna is consists of double strands , in the process of transcription both strands are open , how the transcription facters will know which stand is used as templet for transcription of mrna ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
the picture below shows dna being transcribed by many rna polymerases at the same time , each with an rna `` tail '' trailing behind it . the polymerases near the start of the gene have short rna tails , which get longer and longer as the polymerase transcribes more of the gene . transcription termination rna polymeras...
the polymerases near the start of the gene have short rna tails , which get longer and longer as the polymerase transcribes more of the gene.why and how ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
this , coupled with the stalled polymerase , produces enough instability for the enzyme to fall off and liberate the new rna transcript . what happens to the rna transcript ? after termination , transcription is finished .
what happens if transcription does n't happen properly and there is an error is the rna synthesis ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
transcription uses one of the two exposed dna strands as a template ; this strand is called the template strand . the rna product is complementary to the template strand and is almost identical to the other dna strand , called the nontemplate ( or coding ) strand . however , there is one important difference : in the n...
does the coding strand get transcripted too ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
why can transcription and translation happen simultaneously for an mrna in bacteria ? one reason is that these processes occur in the same 5 ' to 3 ' direction . that means one can follow or `` chase '' another that 's still occurring .
why is uracil only on the 5 ' to 3 ' end and not on the 3 ' to 5 ' end ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
during this process , the dna sequence of a gene is copied into rna . before transcription can take place , the dna double helix must unwind near the gene that is getting transcribed . the region of opened-up dna is called a transcription bubble . transcription uses one of the two exposed dna strands as a template ; th...
is transcription similar to dna replication ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
instead , helper proteins called basal ( general ) transcription factors bind to the promoter first , helping the rna polymerase in your cells get a foothold on the dna . many eukaryotic promoters have a sequence called a tata box . the tata box plays a role much like that of the $ \mbox { - } $ $ 10 $ element in bacte...
also what is polyadenelylation and a tata box ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
if the gene that 's transcribed encodes a protein ( which many genes do ) , the rna molecule will be read to make a protein in a process called translation . rna polymerase rna polymerases are enzymes that transcribe dna into rna . using a dna template , rna polymerase builds a new rna molecule through base pairing .
it 's not in the content but what is a nascent rna ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
transcription overview transcription is the first step of gene expression . during this process , the dna sequence of a gene is copied into rna . before transcription can take place , the dna double helix must unwind near the gene that is getting transcribed .
what 's the terminating sequence of the dna ?
key points : transcription is the process in which a gene 's dna sequence is copied ( transcribed ) to make an rna molecule . rna polymerase is the main transcription enzyme . transcription begins when rna polymerase binds to a promoter sequence near the beginning of a gene ( directly or through helper proteins ) . rna...
let 's take a closer look at what happens during transcription . transcription overview transcription is the first step of gene expression . during this process , the dna sequence of a gene is copied into rna .
does this transcription lead to synthesis of mrna only ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? for starters , the instructions for making proteins are `` written '' in a cell ’ s dna in the form of genes .
do all proteins made in cells start with met ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
two types of molecules with key roles in translation are trnas and ribosomes . transfer rnas ( trnas ) transfer rnas , or trnas , are molecular `` bridges '' that connect mrna codons to the amino amino acids they encode . one end of each trna has a sequence of three nucleotides called an anticodon , which can bind to s...
where are the amino acids attached to the transfer rna coming from ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
finishing up : termination termination is the stage in which the finished polypeptide chain is released . it begins when a stop codon ( uag , uaa , or uga ) enters the ribosome , triggering a series of events that separate the chain from its trna and allow it to drift out of the ribosome . after termination , the polyp...
i 'm confused about what happens when the ribosome runs into a stop codon ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
want to learn more about the structure and function of trnas and ribosomes ? check out the trna and ribosomes article ! steps of translation your cells are making new proteins every second of the day .
is the trna made from dna , or its a preexisting molecule ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
the ribosome provides a set of handy slots where trnas can find their matching codons on the mrna template and deliver their amino acids . these slots are called the a , p , and e sites . not only that , but the ribosome also acts as an enzyme , catalyzing the chemical reaction that links amino acids together to make a...
after it goes through a p e sites , does the site migrate or does the mrna move for new codons to be translated ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
if that idea is new to you , you may want to check out the section on dna to rna to protein ( central dogma ) before getting into the nitty-gritty of building proteins . basically , a gene is used to build a protein in a two-step process : step 1 : transcription ! here , the dna sequence of a gene is `` rewritten '' in...
why is an actual gene that codes for a protein likely to be longer ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
for more details on the steps of elongation , see the stages of translation article . finishing up : termination termination is the stage in which the finished polypeptide chain is released . it begins when a stop codon ( uag , uaa , or uga ) enters the ribosome , triggering a series of events that separate the chain f...
after termination , what happens to the mrna ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
in eukaryotes like you and me , the rna is processed ( and often has a few bits snipped out of it ) to make the final product , called a messenger rna or mrna . step 2 : translation ! in this stage , the mrna is `` decoded '' to build a protein ( or a chunk/subunit of a protein ) that contains a specific series of amin...
for the vast majority of time during elongation in translation , what will you find at the p site of the ribosome ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
all together , this collection of codon-amino acid relationships is called the genetic code , because it lets cells “ decode ” an mrna into a chain of amino acids . overview of translation how is an mrna `` read '' to make a polypeptide ? two types of molecules with key roles in translation are trnas and ribosomes .
how does the mrna `` know '' where to go ?
introduction take a moment to look at your hands . the bone , skin , and muscle you see are made up of cells . and each of those cells contains many millions of proteins $ ^1 $ . as a matter of fact , proteins are key molecular `` building blocks '' for every organism on earth ! how are these proteins made in a cell ? ...
one codon , aug , specifies the amino acid methionine and also acts as a start codon to signal the start of protein construction . there are three more codons that do not specify amino acids . these stop codons , uaa , uag , and uga , tell the cell when a polypeptide is complete .
how do the respective amino-acids `` know '' they are needed at any particular moment ?
in this article we will find the images of different shapes under different reflections . the line of reflection a reflection is a transformation that acts like a mirror : it swaps all pairs of points that are on exactly opposite sides of the line of reflection . the line of reflection can be defined by an equation or ...
your turn ! problem 1 problem 2
will a ruler helps me with this kind of problem forever ?
the first impressionist exhibition , 1874 although the idea originated with claude monet , degas is largely responsible for organizing the very first impressionist exhibition . after much debate , the artists—including degas , monet , renoir , morisot , pissarro , sisley , boudin , and even the young cézanne—along with...
' '' * and on it goes , ever more sarcastically . the article was titled , `` exhibition of the impressionists , '' and the term stuck . from then on , these artists were called impressionists . essay by dr. beth harris and dr. steven zucker *linda nochlin , impressionism and post-impressionism , 1874-1904 : sources an...
did the impressionists signal the end of the government controlled salons or did they continue ?
the first impressionist exhibition , 1874 although the idea originated with claude monet , degas is largely responsible for organizing the very first impressionist exhibition . after much debate , the artists—including degas , monet , renoir , morisot , pissarro , sisley , boudin , and even the young cézanne—along with...
the satirical magazine , le charivari published an account of a visit with joseph vincent , an accomplished and conservative painter : upon entering the first room , joseph vincent received an initial shock in front of the dancer by m. renoir . 'what a pity , ' he said to me , 'that the painter , who has a certain unde...
how come we ca n't draw just read ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
what is the defination of activation energy ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
when mentioning activation energy : energy must be an input in order to start the reaction , but is more energy released during the bonding of the atoms compared to the required activation energy ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
can the energy be harnessed in an industrial setting ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
how is the activation energy changed by a catalytic reagent ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
once a reactant molecule absorbs enough energy to reach the transition state , it can proceed through the remainder of the reaction . activation energy and reaction rate the activation energy of a chemical reaction is closely related to its rate . specifically , the higher the activation energy , the slower the chemica...
does change in temperature change the activation energy of a reaction ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
how can you tell if delta g is negative or positive ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
what is the difference between bond energy , activation energy , chemical energy , potential energy , and free energy ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
once a reactant molecule absorbs enough energy to reach the transition state , it can proceed through the remainder of the reaction . activation energy and reaction rate the activation energy of a chemical reaction is closely related to its rate . specifically , the higher the activation energy , the slower the chemica...
what is a way that the active site of an enzyme is involved in increasing the rate of a biological reaction ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
once a reactant molecule absorbs enough energy to reach the transition state , it can proceed through the remainder of the reaction . activation energy and reaction rate the activation energy of a chemical reaction is closely related to its rate . specifically , the higher the activation energy , the slower the chemica...
what is the source of activation energy in a photochemical reaction ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
do the gibbs energy generally increase or decrease as the reactants forms products ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
how does enzyme reduce activation energy ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
once a reactant molecule absorbs enough energy to reach the transition state , it can proceed through the remainder of the reaction . activation energy and reaction rate the activation energy of a chemical reaction is closely related to its rate . specifically , the higher the activation energy , the slower the chemica...
what would lower activation energy result in ( chemical reaction ) ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
is that possible that activation energy is increases as increase in concentration of alkali in degradation kinetic study ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
what is reason behind increase in activation energy in that case ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
ok just for clarification , when it says the product will be in a lower energy state that does not mean that the product will have a lower energy bond will it ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
the product should have more potential energy inside the bond and if it broke it will release more energy than the reactant would if its bond was broken ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
is activation energy the lowest or the energy for the reaction needed to start ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
once a reactant molecule absorbs enough energy to reach the transition state , it can proceed through the remainder of the reaction . activation energy and reaction rate the activation energy of a chemical reaction is closely related to its rate . specifically , the higher the activation energy , the slower the chemica...
what happens to activation energy of a reaction in solution ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
the higher the barrier is , the fewer molecules that will have enough energy to make it over at any given moment . many reactions have such high activation energies that they basically do n't proceed at all without an input of energy . for instance , the combustion of a fuel like propane releases energy , but the rate ...
halo ahsan king , activation energies cant be always constant ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
this initial energy input , which is later paid back as the reaction proceeds , is called the activation energy and is abbreviated $ \text e_ { \text a } $ . activation energy why would an energy-releasing reaction with a negative ∆g need energy to proceed ? to understand this , we need to look at what actually happens...
does more activation energy mean more free energy ( gibb 's ) ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ?
what is the relation of acid and enymatic acitivity ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
( to be clear , this is a good thing – it would n't be so great if propane canisters spontaneously combusted on the shelf ! ) once a spark has provided enough energy to get some molecules over the activation energy barrier , those molecules complete the reaction , releasing energy . the released energy helps other fuel...
so molecules simply have to reach the barrier ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
( to be clear , this is a good thing – it would n't be so great if propane canisters spontaneously combusted on the shelf ! ) once a spark has provided enough energy to get some molecules over the activation energy barrier , those molecules complete the reaction , releasing energy . the released energy helps other fuel...
what is activation energy and how do molecules get it ?
introduction imagine waking up on a day when you have lots of fun stuff planned . does it ever happen that , despite the exciting day that lies ahead , you need to muster some extra energy to get yourself out of bed ? once you ’ re up , you can coast through the rest of the day , but there ’ s a little hump you have to...
to get the bonds into a state that allows them to break , the molecule must be contorted ( deformed , or bent ) into an unstable state called the transition state . the transition state is a high-energy state , and some amount of energy – the activation energy – must be added in order for the molecule reach it . becaus...
hi there , i was wondering where does the activation energy release to after transition state ?
a story of survival dwelling in the fuchun mountains is a legendary shanshui ( landscape ) painting created by the yuan dynasty painter , huang gongwang . this handscroll , which is over 22 feet long , has a fascinating history . there are many stories associated with it—there are even stories about the inscriptions th...
huang was a han , an ethnic group of china . he also belonged to the social class of literati . the literati were educated elites who were interested in painting , calligraphy and poetry .
on what did the reclusive literati live ?
all of the following terms appear in this unit . the terms are arranged here in alphabetical order . astronomy — the branch of science that deals with the universe and the various objects , like stars , planets , and galaxies , that we find within it . cosmology and astrophysics are closely related to astronomy , and t...
evidence — concrete , verifiable information that either supports or disproves a claim . gravity — the fundamental force of attraction between any two objects that have mass . helium — the second simplest of all chemical elements , helium has two protons and ( almost always ) two neutrons .
why we ca n't explain gravity with quantum mechanics ?
this essay is devoted to a particularly attractive and rare kind of medieval manuscript : the model book . a feast to the eye , the object is filled with drawings and paintings that were meant to show scribes and illuminators how to decorate letters , paint initials , or add large segments of decoration to the page . w...
while this ultimate instruction method took all potential flaws and creativity out of the modeling process , it allowed decorators with lesser talents to produce something beautiful . essay by dr. erik kwakkel additional resources : more information on gregorius bock ’ s scribal pattern book macclesfeld alphabet book a...
some of the imagery seems a little more suggestive no ( the alphabet book ) ?
this essay is devoted to a particularly attractive and rare kind of medieval manuscript : the model book . a feast to the eye , the object is filled with drawings and paintings that were meant to show scribes and illuminators how to decorate letters , paint initials , or add large segments of decoration to the page . w...
the visconti ’ s were important patrons of the arts and so it makes sense that we see their generosity extend into the world of book production . giovannino was known for depicting exotic animals in their natural habitat and this book features such images as well . his pages provided models for other artists who wished...
are some of these 'initials ' depicting human 'folly ' or vices , just as some seem to be depicting declarations of love ( hand to heart ) or virtue etc ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
others are closed in resting neurons and only open in response to a signal . some ion channels are highly selective for one type of ion , but others let various kinds of ions pass through . ion channels that mainly allow $ \text { k } ^+ $ to pass are called potassium channels , and ion channels that mainly allow $ \te...
do our physical movements affect ion exchange ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , there are concentration gradients across the membrane for $ \text { na } ^+ $ and $ \text k^+ $ . ions move down their gradients via channels , leading to a...
at resting membrane potenital do na go in and k out ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , there are concentration gradients across the membrane for $ \text { na } ^+ $ and $ \text k^+ $ . ions move down their gradients via channels , leading to a...
what happens when the concentration of na is increased in the extracellular fluid , is there a depolarization or hyperpolarization ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
so , let 's get a feeling for how the membrane potential works by seeing what would happen in a case where only $ \text k^+ $ can cross the membrane . we 'll start out with $ \text { k } ^+ $ at a higher concentration inside the cell than in the surrounding fluid , just as for a regular neuron . ( other ions are also p...
and the same goes for the increased concentration of k in the extracellular fluid , is there a depolarization or hyperpolarization ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
changing the number of open ion channels provides a way to control the cell ’ s membrane potential and a great way to produce electrical signals . ( we will see the opening and closing of channels again when we discuss action potentials . ) the $ \text { na } ^+ $ - $ \text k^+ $ pump maintains $ \text { na } ^+ $ and ...
so do active pumps or facilitated channels start and fuel action potentials ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
if the $ \text { na } ^+ $ - $ \text k^+ $ pump is shut down , the $ \text { na } ^+ $ and $ \text k^+ $ concentration gradients will dissipate , and so will the membrane potential . like the ion channels that allow $ \text { na } ^+ $ and $ \text k^+ $ to cross the cell membrane , the $ \text { na } ^+ $ - $ \text k^+...
which membrane protein is responsible for restoring the original concentration of na+ and k+ ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
instead , they have to use specialized channel proteins that provide a hydrophilic ( `` water-loving '' ) tunnel across the membrane . some channels , known as leak channels , are open in resting neurons . others are closed in resting neurons and only open in response to a signal .
open or closed channels for depolarization , repolarization and hyperpolarization ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
however , it will be closer to the equilibrium potential of the ion type with higher permeability ( the one that can more readily cross the membrane ) . opening and closing ion channels alters the membrane potential in a neuron , the resting membrane potential is closer to the potassium equilibrium potential than it is...
does the difference in electronegativity of the sodium ion and potassium ion contribute to the membrane potential ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
$ \text { na } ^+ $ is usually present at a much higher concentration outside of a cell than inside , so it will move down its concentration gradient into the cell , making the interior of the cell positive relative to the outside . because of this , the sodium equilibrium potential—the electrical potential difference ...
as in , a na ion is more positive than a k ion due to less shell screening ( not sure if this is even strictly true ) , therefore does this `` more positivity '' contribute at all to the potential difference across the membrane ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
before we look in detail at how these signals are generated , we first need to understand how membrane permeability works in a resting neuron ( one that is not sending or receiving electrical signals ) . in this article , we 'll see how a neuron establishes and maintains a stable voltage across its membrane – that is ,...
is the neuron communication same as the voltage in a wire ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
if the membrane potential becomes more positive than it is at the resting potential , the membrane is said to be depolarized . if the membrane potential becomes more negative than it is at the resting potential , the membrane is said to be hyperpolarized . all of the electrical signals that neurons use to communicate a...
how does applying negative capacitance make a membrane more permeable ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
is membrane potential the same across a neuron ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
( yes , that 's kind of gross , but let 's just imagine it for a second . ) what would happen if you applied an electrical stimulus to the nerve that feeds the frog 's leg ? creepily enough , the dead leg would kick !
what would happen if the balance of ions was to crash and have a higher concentration of one compared to the other ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
so , in a system where $ \text { na } ^+ $ is the only permeant ion , the membrane potential will be positive . in a resting neuron , both $ \text { na } ^+ $ and $ \text { k } ^+ $ are permeant , or able to cross the membrane . $ \text { na } ^+ $ will try to drag the membrane potential toward its ( positive ) equilib...
respected sir/madam what would happen to the resting potential of the membrane if the cell ( neuron ) is equally permeant to na+ and k+ ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion .
what is the threshold measurement ?
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion . in a resting neuron , ...
key points : a resting ( non-signaling ) neuron has a voltage across its membrane called the resting membrane potential , or simply the resting potential . the resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion .
what would happen to the resting potential of a neuron if the concentration of extracellular k+ increases ?
background arc length of function graphs , introduction example 1 : practice with a semicircle consider a semicircle of radius $ 1 $ , centered at the origin , as pictured on the right . from geometry , we know that the length of this curve is $ \pi $ . let 's practice our newfound method of computing arc length to red...
so let 's practice that a few times without worrying about computing the final integral ( you can use a calculator or wolfram alpha once you get a concrete integral ) . example 2 : sine curve what integral represents the arc length of the graph of $ y = \sin ( x ) $ between $ x = 0 $ and $ x = 2\pi $ ? example 3 : up ,...
in the first example with the unit circle i do n't get why x = -cos ( teta ) is n't the x-coordinate simply cos ( teta ) as the trigonometric coordinate are given by the point x = ( x1 , y1 ) = ( cos ( teta ) , sin ( teta ) ) ?
background arc length of function graphs , introduction example 1 : practice with a semicircle consider a semicircle of radius $ 1 $ , centered at the origin , as pictured on the right . from geometry , we know that the length of this curve is $ \pi $ . let 's practice our newfound method of computing arc length to red...
we know from geometry that the arc length is $ \pi $ , but the interesting part is to work through it to see how $ \pi $ pops out when using an arc length integral . ) practice setting up arc length integrals the actual integral you get for arc length is often difficult to compute . however , the important skill to pra...
this method is only valid for integrals of arc lengths right ?
key points most animals need to maintain their core body temperature within a relatively narrow range . endotherms use internally generated heat to maintain body temperature . their body temperature tends to stay steady regardless of environment . ectotherms depend mainly on external heat sources , and their body tempe...
that 's because they have to burn large quantities of fuel—food—to maintain their internal body temperature . why regulate temperature ? there are some basic limits on survivable body temperature for most animals .
how do tardigrades avoid membrane rupture at low extremes of temperature ?
key points most animals need to maintain their core body temperature within a relatively narrow range . endotherms use internally generated heat to maintain body temperature . their body temperature tends to stay steady regardless of environment . ectotherms depend mainly on external heat sources , and their body tempe...
that 's because they have to burn large quantities of fuel—food—to maintain their internal body temperature . why regulate temperature ? there are some basic limits on survivable body temperature for most animals .
and how do they and archaea avoid denaturation at high temperature extremes ?
key points most animals need to maintain their core body temperature within a relatively narrow range . endotherms use internally generated heat to maintain body temperature . their body temperature tends to stay steady regardless of environment . ectotherms depend mainly on external heat sources , and their body tempe...
endotherms use internally generated heat to maintain body temperature . their body temperature tends to stay steady regardless of environment . ectotherms depend mainly on external heat sources , and their body temperature changes with the temperature of the environment . animals exchange heat with their environment th...
is the graph also supposed to demonstrate that ectotherms have minimal oxygen consumption regardless of ambient temperature ?
background second partial derivative test prepare for the slog i have a challenge for you . in this article , you can walk through two examples of finding maxima and minima in multivariable functions . in modern applications , most of the steps involved in solving these sorts of problems would be performed by a compute...
stable point 1 : at $ ( x , y ) = ( 0 , 0 ) $ , the expression evaluates as $ \begin { align } \quad 24x^2 - 16 = 24 ( 0 ) ^2 - 16 = -16 \end { align } $ this is negative , so according to the second partial derivative test , the point $ ( 0 , 0 ) $ is a stable point 2 : at $ ( x_0 , y_0 ) = ( \sqrt { 2 } , 0 ) $ , the...
in problem 2 , is n't ( 2,2 ) also a solution ?
one of the most widely imitated artists michelangelo merisi da caravaggio was famously sensitive when it came to matters of artistic originality : he threatened both the painter guido reni and artist and biographer giovanni baglione for copying his style . despite his best efforts to protect his singular style , howeve...
nevertheless , these painters , often labeled caravaggisti , emulated aspects of caravaggio ’ s style , technique , and choice of subjects and were responsible for the dissemination of caravaggism across the european continent . a distinctive style these followers , whether italian , spanish , french , or netherlandish...
what is the difference between `` tenebrism and chiaroscuro '' style of painting ?
one of the most widely imitated artists michelangelo merisi da caravaggio was famously sensitive when it came to matters of artistic originality : he threatened both the painter guido reni and artist and biographer giovanni baglione for copying his style . despite his best efforts to protect his singular style , howeve...
painters like cecco del caravaggio , orazio gentileschi and his daughter , artemisia gentileschi , or grammatica , who knew caravaggio personally , did have the benefit of direct contact with the source of their inspiration , but their work retains a character all its own . the gentileschi—both father and daughter—prod...
could it be ( from the preceeding paintings displayed ) that north american artist norman rockwell was also a student of caravaggio ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
why is this 2,000 year old cloth in the `` prehistoric '' category ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
`` what the women were wearing : a deposit of early nasca dresses and shawls from cahuachi , peru . '' textile museum journal , 42/43:13–53 . paul , anne .
how and what did they use to dye the rainbow of colors found on the textile ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
like some other very fine cloths , the brooklyn textile is finished so carefully on both sides that it is almost impossible to distinguish which is the correct side . although the central cloth and its framing dimensional border are created by different techniques , both display perfect reversibility—except for three b...
why would the border of the cloth have survived so much better than the interior of the cloth ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
garments the border figures ’ clothing also matches examples found archaeologically , and some bear miniscule designs that faithfully represent embroidered decorations found on life-sized garments . some wear wrap-around dresses of a style worn by women in ancient times ; others wear two-part outfits , associated with ...
would n't the thin , narrow decorative pieces wear away faster ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
like some other very fine cloths , the brooklyn textile is finished so carefully on both sides that it is almost impossible to distinguish which is the correct side . although the central cloth and its framing dimensional border are created by different techniques , both display perfect reversibility—except for three b...
it seems like the interior style differs greatly to the border- could this piece have been assembled over many generations ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
what are some of the fibers used to make this thing for burial ?
mummy bundles one of the most extraordinary masterpieces of the pre-columbian americas is a nearly 2,000-year-old cloth from the south coast of peru , which has been in the collection of the brooklyn museum of art since 1938 . despite the textile's small size ( it measures about two by five feet ) , it contains a vast ...
most of the animals and plants that appear can be tied to species still found on the south coast , and many human figures wear or carry items that directly relate to the archaeological record . their jewelry , for example , corresponds to specimens formed from thin sheets of gleaming gold . these include : “ forehead o...
what did the gold accessories have to do with textiles ?
background green 's theorem two-dimensional flux constructing the unit normal vector of a curve divergence not strictly required , but helpful for a deeper understanding : formal definition of divergence what we 're building to the 2d divergence theorem is to divergence what green 's theorem is to curl . it relates the...
for example , if the line integral you want to compute begins its life as a flux integral , rather than expanding out this line integral to make it look like $ \displaystyle \int p\ , dx + q\ , dy $ and applying green 's theorem , you could recognize immediately that it 's the same as doubly integrating divergence . su...
if green 's theorem relates to curl and the 2d divergence theorem relates flux to divergence , how can these two theorems mean exactly the same thing ?
what is this object ? this is a jade object in the form of a cicada ( tsan ) used for burial purposes in the han dynasty ( 206 bce–220 c.e . ) . specifically , this jade was meant to be placed on the tongue , and was part of a set of jade plugs or coverings for the body . the cicada has been partly abstracted to emphas...
at first , pieces of jade covered different parts of the head and were attached to a veil or fabric of some sort . this practice evolved into more complex sets of jades , including pendants and necklaces covering the upper part of the body . it was during the han dynasty that full jade suits or jade casings covering th...
why would they focus on covering the orifices found in the body ?
what is this object ? this is a jade object in the form of a cicada ( tsan ) used for burial purposes in the han dynasty ( 206 bce–220 c.e . ) . specifically , this jade was meant to be placed on the tongue , and was part of a set of jade plugs or coverings for the body . the cicada has been partly abstracted to emphas...
cicadas , like this light green piece , were the favored burial jade of the han dynasty . these were placed on the tongue of the deceased and usually were used in conjunction with jade plugs for the nine body orifices . these plugs were believed to prevent the body from decay and to preserve the vital spirit or qi , th...
why the cicada was placed on the tongue ?
the rock-cut façades are the iconic monuments of petra . of these , the most famous is the so-called treasury ( or khazneh ) , which appeared in the film indiana jones and the last crusade , as the final resting place of the holy grail . the prominence of the tombs in the landscape led many early explorers and scholars...
no human remains have ever been found in any of the tombs , and the exact funerary practices of the nabataeans remain unknown . the dating of the tombs has proved difficult as there are almost no finds , such as coins and pottery , that enable archaeologists to date these tombs ; a few inscriptions allow us to date som...
if the following is correct ... then how can we be certain that these `` tombs '' were tombs at all ?
the rock-cut façades are the iconic monuments of petra . of these , the most famous is the so-called treasury ( or khazneh ) , which appeared in the film indiana jones and the last crusade , as the final resting place of the holy grail . the prominence of the tombs in the landscape led many early explorers and scholars...
thus , while the monastery deploys many elements of classical architecture , it does so in a unique way . essay by dr. elizabeth macaulay-lewis additional resources : google interactive tour of petra ( includes audio ) the natataean kingdom and petra unesco : petra
so how did the people of petra counteract these natural forces of wind and water erosion and instability when they carved this sandstone into buildings ?
we encounter electrochemical cells in all facets of our everyday lives from the disposable aa batteries in our remote controls and the lithium-ion batteries in our iphones to the nerve cells strewn throughout our bodies . there are two types of electrochemical cells : galvanic , also called voltaic , and electrolytic ....
apply a reverse voltage to a voltaic cell . we encounter electrolytic cells during the charging phase of any type of rechargeable battery from the lead-acid battery in automobiles to the lithium-ion battery in smartphones . in comparison to the galvanic cell , the electrodes of an electrolytic cell can be placed in a s...
what is the full form of aa battery ?
we encounter electrochemical cells in all facets of our everyday lives from the disposable aa batteries in our remote controls and the lithium-ion batteries in our iphones to the nerve cells strewn throughout our bodies . there are two types of electrochemical cells : galvanic , also called voltaic , and electrolytic ....
galvanic cells galvanic cells traditionally are used as sources of dc electrical power . a simple galvanic cell may contain only one electrolyte separated by a semi-porous membrane , while a more complex version involves two separate half-cells connected by a salt bridge . the salt bridge contains an inert electrolyte ...
when you mention about the salt bridge what is the significance for it to be inert ?
we encounter electrochemical cells in all facets of our everyday lives from the disposable aa batteries in our remote controls and the lithium-ion batteries in our iphones to the nerve cells strewn throughout our bodies . there are two types of electrochemical cells : galvanic , also called voltaic , and electrolytic ....
since voltage is an intensive property , which is one that does not depend on the system size or the amount of material in the system , we do not have to multiply the emf by any stoichiometric coefficient to cancel out the electrons in calculating emf . calculating the gibbs free energy from emf suppose we are asked to...
what is gibbs free energy ?
we encounter electrochemical cells in all facets of our everyday lives from the disposable aa batteries in our remote controls and the lithium-ion batteries in our iphones to the nerve cells strewn throughout our bodies . there are two types of electrochemical cells : galvanic , also called voltaic , and electrolytic ....
let ’ s keep in mind that when we flip the reduction potential into an oxidation potential , we also need to flip the sign . since galvanic cells have a positive emf , we are looking to flip the equation that when added to the other emf will give us a positive value . by flipping the zinc half-reaction , we have the tw...
do the emf values need to be known for the mcat ?
key points : a community 's structure can be described by its species richness , which is the number of species present , and species diversity , which is a measure of both species richness and species evenness ( relative numbers ) . community structure is influenced by many factors , including abiotic factors , specie...
foundation and keystone species some species have unusually strong impacts on community structure , preserving the balance of the community or even making its existence possible . these `` special '' species include foundation and keystone species . foundation species a foundation species plays a unique , essential rol...
is it possible for there to be more than one keystone species in an area , as well as foundation species ?
key points : a community 's structure can be described by its species richness , which is the number of species present , and species diversity , which is a measure of both species richness and species evenness ( relative numbers ) . community structure is influenced by many factors , including abiotic factors , specie...
however , the diversity-stability relationship is n't a universal rule , and there are some cases where other factors ( besides species diversity ) are more important in determining community and ecosystem stability $ ^ { 5,6 } $ . what factors shape community structure ? the structure of a community is the result of m...
how does climate shape a biological community ?