Lec. 15: Intro of Metabolism/ Metabolic Fuels Flashcards
What factors account for the high phosphoryl-transfer potential of nucleoside triphosphates, NTPs?
A) low standard free energy of hydrolysis
B) increase in entropy
C) resonance stabilization
D) stabilization by hydration
E) decrease in entropy
B) increase in entropy
C) resonance stabilization
D) stabilization by hydration
ATP has a very high phosphoryl transfer potential for many reasons. Which statement below is NOT such a reason?
A) Charge repulsion lower after ATP hydrolysis
B) Resonance stabilization of ATP hydrolysis products
C) Decrease in entropy after ATP hydrolysis
D) Stabilization by hydration after ATP hydrolysis
E) More hydrogen bond donors and acceptors after ATP hydrolysis
C) Decrease in entropy after ATP hydrolysis
Resonance stabilization:
A) orthophosphate (Pi) has greater resonance stabilization than ATP
B) repulsion between phosphates is reduced when ATP is hydrolyzed
C) entropy of the products of ATP hydrolysis is greater: 2 products instead of 1
D) water bunds to ADP and Pi, stabilizing these molecules
A) orthophosphate (Pi) has greater resonance stabilization than ATP
Electrostatic repulsion:
A) orthophosphate (Pi) has greater resonance stabilization than ATP
B) repulsion between phosphates is reduced when ATP is hydrolyzed
C) entropy of the products of ATP hydrolysis is greater: 2 products instead of 1
D) water bunds to ADP and Pi, stabilizing these molecules
B) repulsion between phosphates is reduced when ATP is hydrolyzed
Increase in entropy:
A) orthophosphate (Pi) has greater resonance stabilization than ATP
B) repulsion between phosphates is reduced when ATP is hydrolyzed
C) entropy of the products of ATP hydrolysis is greater: 2 products instead of 1
D) water bunds to ADP and Pi, stabilizing these molecules
C) entropy of the products of ATP hydrolysis is greater: 2 products instead of 1
Stabilization due to hydration:
A) orthophosphate (Pi) has greater resonance stabilization than ATP
B) repulsion between phosphates is reduced when ATP is hydrolyzed
C) entropy of the products of ATP hydrolysis is greater: 2 products instead of 1
D) water bunds to ADP and Pi, stabilizing these molecules
D) water bunds to ADP and Pi, stabilizing these molecules
ATP has a high phosphoryl group transfer potential because:
A) it has a high rate of spontaneous hydrolysis at physiological pH and temperature.
B) it turns into water molecules easily.
C) it has three phosphate groups linked to three sulfur groups.
D) cleavage of either of its two phosphoanhydride bonds proceeds with a large negative △Go’ of hydrolysis
D) cleavage of either of its two phosphoanhydride bonds proceeds with a large negative △Go’ of hydrolysis
Which statement is true regarding
the oxidation of carbon fuels?
A. In most aerobic organisms, the carbon in fuel molecules, including glucose and fats, is oxidized to O2.
B. The ultimate electron acceptor for the aerobic oxidation of carbon is CO2.
C. The free energy of oxidation of single-carbon compounds decreases with the degree of hydrogen saturation.
D. Energy of oxidation can be trapped as a high-phosphoryl- transfer potential compound and used to form ATP.
E. Electrons captured during the oxidation of carbon fuels are used to generate ADP and Pi from ATP.
D. Energy of oxidation can be trapped as a high-phosphoryl- transfer potential compound and used to form ATP.
Which of the following best characterizes NADH and NADPH?
a. NADH and NADPH are interchangeably used for both ATP generation and biosynthesis.
b. NADH is primarily used for ATP generation, whereas NADPH is primarily used for biosynthesis.
c. NADPH is primarily used for ATP generation, whereas NADH is primarily used for biosynthesis.
d. Both ATP generation and biosynthesis preferentially use NADH over NADPH.
b. NADH is primarily used for ATP generation, whereas NADPH is primarily used for biosynthesis.
Acetyl-CoA:
A. can be fully oxidized to CO2.
B. can be used to synthesize fatty acids.
C. is the breakdown product of fatty acid
oxidation.
D. A and B
E. All of the above
E. All of the above
Which of the following can be used as a metabolic control mechanism?
A) Enzyme compartmentalization
B) Action of hormones
C) Covalent modification of an enzyme
D) Regulation of enzyme activity
E) All of the above
E) All of the above
Imagine that you just consumed delicious strawberry ice cream. For simplicity, let’s say that the ice cream treat ONLY contains lactose and sucrose. Which of the following enzymes would you expect to be active to help you digest your tasty snack (assume that you are not lactose intolerant)?
A) maltase & a-amylase
B) sucrase & lactase
C) fructase & lactase
D) a-amylase & sucrase
E) lipases & maltase
B) sucrase & lactase
Creatine phosphate is an example of substrate-level phosphorylation.
How does it fuel a sprint?
A. Creatine phosphate uses ADP from ATP to fuel a sprint.
B. Creatine phosphate isn’t needed, because muscles produce enough
ATP to fuel a short burst of energy,
C. Creatine phosphate uses ATP from ADP to fuel a sprint.
D. Creatine phosphate is an enzyme used in metabolic pathways, and it
creates energy in a metabolic pathway to fuel a sprint.
C. Creatine phosphate uses ATP from ADP to fuel a sprint.
