CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
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2022
Intro Bio Questions and answer archive. Use the find function to search for topics
of interest
1 Q: What constitutes a monomer? And if steroids are not monomers, what
are they
1 A: The use of the word \"monomer\" implies that there is a higher order
form of the molecule consisting of more than one monomer linked together.
The minimum use of a monomer would be to form a dimer, such as fructose in
forming sucrose (forever a dimer). The word can also be applied to large
molecules such as polypepides: thus hemoglobin is made up of 4 monomer
subunits. So a monomer is not synonymous with \"small molecule.\" A small
molecule could be a monomer if a polymer incorporatiing it exists, such as
glycine being a monomer for a polypeptide. Other small molecules may never
be incorpated into a polymer, such as folic acid (a vitamin) or testosterone (a
steroid hormone). Such small molecules do not have the right to be called
monomers. ',1),(###-09- 22&&
2 Q: In Lecture 4, you mention that asp-asn is an H-bond to ionic, but then
in 3i) of exam 2002, the answer says that no ionic bonds can be formed
between peptides A and B. What about the \"H- bond to ionic\" asn-asp
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
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2022
,CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
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2022
2 A: An ionic bond is a bond between two ions. The electrical attraction
between a polar (un- ionized) group (a dipole) and an ion is not really an ionic
bond, not a full ionic bond. I have called it a combination ionic, but it may be
better described as \"charge-dipole interaction.\" Such interactions are usually
described in the context of \"solvation\" of an ion by water dipoles. So this less
overlapping name is probably a better idea, and hopefully eliminated the
apparent conflict. ',1),(###-09-22&&
3 Q: In 5a of the 2002 exam, how do you know that Vmax won\'t be
reached at substrate concentration = 2Km
3 A: Because the shape of the Vo vs. S curve. Vmax is never reached, it
is only approached asymptotically. 1),(###-09-22&&
4 Q: Is it safe to say that any cell-produced inhibitor is allosteric, unless
it\'s the example you mention above? Or are there cell-produced,
physiological competitive inhibitors, too
4 A: As far as I know all inhibitors used to control cell metabolism are of the
allosteric type.
*1),(###-09-22&&
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
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2022
,CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
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5 Q: Is it true that all allosteric inhibitors are non-competitive, but that not
all non-competitive inhibitors are allosteric
5 A: No, allosterics are in a separate class. They do not obey the simple
Michaelis-Menten kinetics that we have presented here. That is, even the curves
for Vo vs. S are different. The mechanism is more complex. Non-competitve
inhibitors on the other hand do follow Michaelis-Menten kinetics, in the way
shown in lecture. Indeed they are defined this way, by their kinetic behavior. A
mechanism by which a non-competitive inhibitor blocks a catalytic site without
blocking substrate binding and without distorting the enzyme would explain this
kinetic behavior (lower Vmax, same Km).',1),(###-09-22&&
6 Q: One of my Chemistry professors made a specific point during our
discussion that catalysts don\'t alter the activation energy, they alter the
mechanism by which the reaction proceeds, and this alternate pathway
corresponds to a lower activation energy. He was very emphatic about how
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
, CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
incorrect it was to state that \"catalysts act by reducing the activation energy\"
- yet this is what is in your notes and the text. Can you reconcile these
seemingly contradictory statements for me
6 A: I\'m glad you brought this up and got an expert opinion from a chemist.
I have always felt a little uncomfortable talking about the activation energy being
\"lowered,\" even though that\'s what it says in most biochemistry texts. I think
your chemistry professor\'s explanation is much more reasonable and provides a
better insight into what\'s going on. The energy needed to reach a transition
state by the simple collision of the two molecules represents the activation
energy for that situation and nothing can lower it for that situation. The catalyst
brings the two molecules together by a different mechanism, (binding them side
by side often) and a transition state can be reached in this situation with much
less input of energy. We don\'t need the great kinetic energy necessary in the
uncatalyzed reaction. So I like his phrasing. Nevertheless the fact remains that in
the presence of the catalyst, the activation energy needed is less, it is lower,
than in the uncatalyzed situation. So I can understand why one might say \"In
the presence of a catalyst the activation energy to reach a transtition state is
lower.\", and then \"Catalysts work by allowing a lower activation energy\" and
then it\'s short step to \'Catalysts act by lowering the activation energy\" which
could even be considered to be literally if loosely true, but I agree is misleading.
Indeed, I plan to incorporate this way of explaining catalysts into future years\'
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
Intro Bio Questions and answer archive. Use the find function to search for topics
of interest
1 Q: What constitutes a monomer? And if steroids are not monomers, what
are they
1 A: The use of the word \"monomer\" implies that there is a higher order
form of the molecule consisting of more than one monomer linked together.
The minimum use of a monomer would be to form a dimer, such as fructose in
forming sucrose (forever a dimer). The word can also be applied to large
molecules such as polypepides: thus hemoglobin is made up of 4 monomer
subunits. So a monomer is not synonymous with \"small molecule.\" A small
molecule could be a monomer if a polymer incorporatiing it exists, such as
glycine being a monomer for a polypeptide. Other small molecules may never
be incorpated into a polymer, such as folic acid (a vitamin) or testosterone (a
steroid hormone). Such small molecules do not have the right to be called
monomers. ',1),(###-09- 22&&
2 Q: In Lecture 4, you mention that asp-asn is an H-bond to ionic, but then
in 3i) of exam 2002, the answer says that no ionic bonds can be formed
between peptides A and B. What about the \"H- bond to ionic\" asn-asp
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
,CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
2 A: An ionic bond is a bond between two ions. The electrical attraction
between a polar (un- ionized) group (a dipole) and an ion is not really an ionic
bond, not a full ionic bond. I have called it a combination ionic, but it may be
better described as \"charge-dipole interaction.\" Such interactions are usually
described in the context of \"solvation\" of an ion by water dipoles. So this less
overlapping name is probably a better idea, and hopefully eliminated the
apparent conflict. ',1),(###-09-22&&
3 Q: In 5a of the 2002 exam, how do you know that Vmax won\'t be
reached at substrate concentration = 2Km
3 A: Because the shape of the Vo vs. S curve. Vmax is never reached, it
is only approached asymptotically. 1),(###-09-22&&
4 Q: Is it safe to say that any cell-produced inhibitor is allosteric, unless
it\'s the example you mention above? Or are there cell-produced,
physiological competitive inhibitors, too
4 A: As far as I know all inhibitors used to control cell metabolism are of the
allosteric type.
*1),(###-09-22&&
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
,CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
5 Q: Is it true that all allosteric inhibitors are non-competitive, but that not
all non-competitive inhibitors are allosteric
5 A: No, allosterics are in a separate class. They do not obey the simple
Michaelis-Menten kinetics that we have presented here. That is, even the curves
for Vo vs. S are different. The mechanism is more complex. Non-competitve
inhibitors on the other hand do follow Michaelis-Menten kinetics, in the way
shown in lecture. Indeed they are defined this way, by their kinetic behavior. A
mechanism by which a non-competitive inhibitor blocks a catalytic site without
blocking substrate binding and without distorting the enzyme would explain this
kinetic behavior (lower Vmax, same Km).',1),(###-09-22&&
6 Q: One of my Chemistry professors made a specific point during our
discussion that catalysts don\'t alter the activation energy, they alter the
mechanism by which the reaction proceeds, and this alternate pathway
corresponds to a lower activation energy. He was very emphatic about how
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
, CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
incorrect it was to state that \"catalysts act by reducing the activation energy\"
- yet this is what is in your notes and the text. Can you reconcile these
seemingly contradictory statements for me
6 A: I\'m glad you brought this up and got an expert opinion from a chemist.
I have always felt a little uncomfortable talking about the activation energy being
\"lowered,\" even though that\'s what it says in most biochemistry texts. I think
your chemistry professor\'s explanation is much more reasonable and provides a
better insight into what\'s going on. The energy needed to reach a transition
state by the simple collision of the two molecules represents the activation
energy for that situation and nothing can lower it for that situation. The catalyst
brings the two molecules together by a different mechanism, (binding them side
by side often) and a transition state can be reached in this situation with much
less input of energy. We don\'t need the great kinetic energy necessary in the
uncatalyzed reaction. So I like his phrasing. Nevertheless the fact remains that in
the presence of the catalyst, the activation energy needed is less, it is lower,
than in the uncatalyzed situation. So I can understand why one might say \"In
the presence of a catalyst the activation energy to reach a transtition state is
lower.\", and then \"Catalysts work by allowing a lower activation energy\" and
then it\'s short step to \'Catalysts act by lowering the activation energy\" which
could even be considered to be literally if loosely true, but I agree is misleading.
Indeed, I plan to incorporate this way of explaining catalysts into future years\'
CHEM 200 INTRO BIO EXAM QUESTIONS AND ANSWERS BEST
SOLUTIONS RATED A+ GUARANTEED SUCCESS NEW UPDATE
2022
