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Chem 153a - Final Exam With Complete Solutions
100% 2026||Verified Exam!!!
What is substrate-level phosphorylation? - Answers-
Production of ATP or GTP by transfer of phosphate group
from a substrate (higher energy) to ADP or GDP
What conditions are required for substrate-level
phosphorylation occurrence? - Answers-Needs to be a
higher energy phosphate-containing phosphate compound
that when cleaved generates more energy than ADP + Pi -
> ATP requires
What makes a thioester bond high-energy? - Answers-
Structure undergoes less resonance stabilization than
oxygen esters and therefore more energy is released upon
their hydrolysis
Which reactions/pathways produce acetyl-CoA? -
Answers-Pyruvate and PDC (pyruvate decarboxylation)
Catabolism of AA's (isoleucine, leucine, threonine)
Beta oxidation of fatty acids
Ketone bodies
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Which pathways consume acetyl-CoA? - Answers-TCA
cycle
Fatty acid synthesis
Ketone bodies
Why is acetyl delivery useful? - Answers-It adds two
carbons to compounds and also serves as a cofactor for
protein acetylation
Its main function is to deliver the acetyl group to the citric
acid cycle (Krebs cycle) to be oxidized for energy
production.
What role do these coenzymes (NAD+ and NADP+) play?
Be able to write out the general reactions for either
molecule. - Answers-Serve as electron carriers
Free molecules that bind to active site to assist with
catalysis
NAD+ generally assists in oxidations of catabolism (lec
24).
NADPH assists in reductions in anabolism (lec 24).
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NAD+ + 2e- —--> NADH + H+
NADP+ + 2e- —> NADPH + H+
Why do both of these molecules (NAD+ and NADP+)
exist? What utility does this provide? - Answers-Ratios
serve as gauges of cell's energy status
Many proteins use NAD+ as a substrate, the availability
could be a sign of cellular stress
Be able to discuss the basal ratios of both coenzymes and
connect them to their roles - Answers-Basal ratio of NAD+
: NADH is usually high (more NAD+), favors formation of
NADH
Basal ratio of NADP+ : NADPH is low, favoring hydride
transfer from NADPH to a substrate
Ratios serve as gauges of cell's energy status
Many proteins use NAD+ as a substrate, the availability
could be a sign of cellular stress
What could a high basal ratio of NAD+ imply and why? -
Answers-It implies that NADH formation is favored and is
thus reduced in catabolic pathways
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NAD+ acts as a substrate for a number of enzymes,
including sirtuins. Sirtuins transmit a stress response,
which makes sense because a high ratio of NAD+ implies
dysregulation (energy-poor cell)
If NAD+:NADH is unusually high it means your energy
stores have been depleted (Glycolysis +TCA which
produce NADH have NOT been active).
How would you quantify the concentration of
NADH/NADPH? What would this quantification be useful
for? Understand this application. - Answers-By taking the
UV Absorption of a reaction, you can quantify the amount
of NADH/NADPH present as they each have certain
bands that arise.
This application would be useful in determining if a
reaction is catabolic or anabolic
Useful for evaluating the kinematics of an enzymatic
reaction
NADH has a new band at 340, NADPH has same band
Be able to recognize the full structure of FMN. - Answers-
Be able to recognize the full structure of FAD. - Answers-
Chem 153a - Final Exam With Complete Solutions
100% 2026||Verified Exam!!!
What is substrate-level phosphorylation? - Answers-
Production of ATP or GTP by transfer of phosphate group
from a substrate (higher energy) to ADP or GDP
What conditions are required for substrate-level
phosphorylation occurrence? - Answers-Needs to be a
higher energy phosphate-containing phosphate compound
that when cleaved generates more energy than ADP + Pi -
> ATP requires
What makes a thioester bond high-energy? - Answers-
Structure undergoes less resonance stabilization than
oxygen esters and therefore more energy is released upon
their hydrolysis
Which reactions/pathways produce acetyl-CoA? -
Answers-Pyruvate and PDC (pyruvate decarboxylation)
Catabolism of AA's (isoleucine, leucine, threonine)
Beta oxidation of fatty acids
Ketone bodies
,2|Page
Which pathways consume acetyl-CoA? - Answers-TCA
cycle
Fatty acid synthesis
Ketone bodies
Why is acetyl delivery useful? - Answers-It adds two
carbons to compounds and also serves as a cofactor for
protein acetylation
Its main function is to deliver the acetyl group to the citric
acid cycle (Krebs cycle) to be oxidized for energy
production.
What role do these coenzymes (NAD+ and NADP+) play?
Be able to write out the general reactions for either
molecule. - Answers-Serve as electron carriers
Free molecules that bind to active site to assist with
catalysis
NAD+ generally assists in oxidations of catabolism (lec
24).
NADPH assists in reductions in anabolism (lec 24).
,3|Page
NAD+ + 2e- —--> NADH + H+
NADP+ + 2e- —> NADPH + H+
Why do both of these molecules (NAD+ and NADP+)
exist? What utility does this provide? - Answers-Ratios
serve as gauges of cell's energy status
Many proteins use NAD+ as a substrate, the availability
could be a sign of cellular stress
Be able to discuss the basal ratios of both coenzymes and
connect them to their roles - Answers-Basal ratio of NAD+
: NADH is usually high (more NAD+), favors formation of
NADH
Basal ratio of NADP+ : NADPH is low, favoring hydride
transfer from NADPH to a substrate
Ratios serve as gauges of cell's energy status
Many proteins use NAD+ as a substrate, the availability
could be a sign of cellular stress
What could a high basal ratio of NAD+ imply and why? -
Answers-It implies that NADH formation is favored and is
thus reduced in catabolic pathways
, 4|Page
NAD+ acts as a substrate for a number of enzymes,
including sirtuins. Sirtuins transmit a stress response,
which makes sense because a high ratio of NAD+ implies
dysregulation (energy-poor cell)
If NAD+:NADH is unusually high it means your energy
stores have been depleted (Glycolysis +TCA which
produce NADH have NOT been active).
How would you quantify the concentration of
NADH/NADPH? What would this quantification be useful
for? Understand this application. - Answers-By taking the
UV Absorption of a reaction, you can quantify the amount
of NADH/NADPH present as they each have certain
bands that arise.
This application would be useful in determining if a
reaction is catabolic or anabolic
Useful for evaluating the kinematics of an enzymatic
reaction
NADH has a new band at 340, NADPH has same band
Be able to recognize the full structure of FMN. - Answers-
Be able to recognize the full structure of FAD. - Answers-
