CHEM 3438 Exam 4
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https://quizlet.com/_8xna2k
1.In the absence of lactose,: the genes of the lac operon (lacZ, lacY,
and lacA) are not transcribed.
2.An operon is a cluster of linked genes under the control of a single
promoter. (T/F): True
3.If a cell contains galactosidase activity of 2 umol/min lactose hydrolyzed,
and gene expression is increased three-fold (so if it was 100% before the
increase, it is 300% after), what is the resulting increase in rate of lactose
hydrolysis if we assume all RNA is converted equally efficiently to protein
in both cases?: 6 umol/min
4.The lac operon is repsonsible for the metabolism of lactose in
humans. (T/F): False
5.The lac operator is the protein that binds to the DNA to stop
transcription of the lac operon. (T/F): False
6.The lac repressor changes shape when it binds to lactose. (T/F): True
7.CTP slows down aspartate transcarbamoylase (ATCase). This is an
example of: feedback inhibition
8.CTP pushes ATCase into the: T-state
9.The substrate aspartate binds to (and promotes) the of
ATCase.: R-state
10.The R state of aspartate transcarbamoylase (ATCase): binds aspartate
more tightly than the T state.
11.CTP binds to the of ATCase.: both C and D (r-subunits
and T state)
12.Aspartate transcarbamoylase (ATCase) is a typical enzyme that is
regulat- ed to regulate the enzyme's entire pathway in that: All of the above
(it catalyzes a very energetically favorable reaction, it catalyzes a step
that commits metabolites to a pathway, it is allosterically regulated, it is
multimeric - has multiples subunits)
13.The state of ATCase has higher activity than the state.-
: R,T
14.The form of lactate dehydrogenase found in heart tissue has a
affinity for substrate compared to the muscle form of hte en-
zyme. Enzymes that have multiple forms like that are called .:
- high, isozymes
15.Isozymes can differ in multiple properties, including Km, Vmax, and
sensi- tivity to regulation. (T/F): True
16.You are developing a medical test for tissue damage using the presence
of the enzyme pyruvate dehydrogenase in the bloodstream as a marker for
that damage. The amount of the enzyme activity present in blood is
1/
8
, CHEM 3438 Exam 4
Study online at
proportional to the amount of
https://quizlet.com/_8xna2k damaged tissue. If the activity is measured
with a saturat-
2/
8
Study online at
https://quizlet.com/_8xna2k
1.In the absence of lactose,: the genes of the lac operon (lacZ, lacY,
and lacA) are not transcribed.
2.An operon is a cluster of linked genes under the control of a single
promoter. (T/F): True
3.If a cell contains galactosidase activity of 2 umol/min lactose hydrolyzed,
and gene expression is increased three-fold (so if it was 100% before the
increase, it is 300% after), what is the resulting increase in rate of lactose
hydrolysis if we assume all RNA is converted equally efficiently to protein
in both cases?: 6 umol/min
4.The lac operon is repsonsible for the metabolism of lactose in
humans. (T/F): False
5.The lac operator is the protein that binds to the DNA to stop
transcription of the lac operon. (T/F): False
6.The lac repressor changes shape when it binds to lactose. (T/F): True
7.CTP slows down aspartate transcarbamoylase (ATCase). This is an
example of: feedback inhibition
8.CTP pushes ATCase into the: T-state
9.The substrate aspartate binds to (and promotes) the of
ATCase.: R-state
10.The R state of aspartate transcarbamoylase (ATCase): binds aspartate
more tightly than the T state.
11.CTP binds to the of ATCase.: both C and D (r-subunits
and T state)
12.Aspartate transcarbamoylase (ATCase) is a typical enzyme that is
regulat- ed to regulate the enzyme's entire pathway in that: All of the above
(it catalyzes a very energetically favorable reaction, it catalyzes a step
that commits metabolites to a pathway, it is allosterically regulated, it is
multimeric - has multiples subunits)
13.The state of ATCase has higher activity than the state.-
: R,T
14.The form of lactate dehydrogenase found in heart tissue has a
affinity for substrate compared to the muscle form of hte en-
zyme. Enzymes that have multiple forms like that are called .:
- high, isozymes
15.Isozymes can differ in multiple properties, including Km, Vmax, and
sensi- tivity to regulation. (T/F): True
16.You are developing a medical test for tissue damage using the presence
of the enzyme pyruvate dehydrogenase in the bloodstream as a marker for
that damage. The amount of the enzyme activity present in blood is
1/
8
, CHEM 3438 Exam 4
Study online at
proportional to the amount of
https://quizlet.com/_8xna2k damaged tissue. If the activity is measured
with a saturat-
2/
8
