Biochemistry 451 Exam 1 Past Questions

With respect to decarboxylation of pyruvate:

a. it can work non-oxidatively in yeast

b. FADH2 and NADH are required

c. lipoamide is required for reduction of acetaldehyde

d. it produces acetyl-CoA when there is no NAD+

e. all of the above are true

d. none of the above are true

a. it can work non oxidatively in yeast

With respect to fermentation in yeast:

a. acetaldehyde gets oxidized

b. NAD+ is used making ethanol

c. NADH is produced in making ethanol

d. all of the above are true

e. none of the above are true

e. none of the above are true

With respect to the Citric Acid Cycle:

a. it can produce and use CO2 in the forward direction

b. it occurs in the mitochondrion

c. each turn of the cycle directly produces one GDP

d. all of the above are true

e. none of the above are true

b. it occurs in the mitochondrion

With respect to the second decarboxylation of the citric acid cycle:

a. it produces NAD+

b. it is oxidative in all organisms

c. it is catalyzed by isocitrate dehydrogenase

d. all of the above are true

e. none of the above are true

b. it is oxidative in all organisms

With respect to the enzymes of the citric acid cycle:

a. citrate synthase catalyzes an oxidation that is energetically favorable

b. isocitrate dehydrogenase requires 5 coenzymes

c. citrate synthase catalyzes conversion of citrate to isocitrate

d. they are mostly activated when NADH is abundant

e. all of the above are true

f. none of the above are true

a. citrate synthase catalyzes an oxidation that is energetically favorable

With respect to the glyoxylate cycle:

a. it is not a means of making glucose in plants

b. it uses the enzyme aconitase

c. it involves only one decarboxylation

d. all of the above are true

e. none of the above are true

b. it uses the enzyme aconite

With respect to fatty acids:

a. they are found in phosphatides, fats, and sphingolipids

b. they can be unsaturated even if they contain only one double bond

c. they are mostly non-polar

d. all of the above are true

e. none of the above are true

d. all of the above are true

With respect to lipids in membranes:

a. they include sphingolipids, glycerophospholipids and cholesterol

b. they can contain saturated and unsaturated fatty acids

c. they do not all contain fatty acids

d. all of the above are true

e. none of the above are true

d. all of the above are true

With respect to membrane transport:

a. diffusion driven transport requires no external energy

b. active transport always moves at least one molecule with a concentration gradient

c. ARP is the only source of energy for active transport

d. all of the above are true

e. none of the above are true

a. diffusion driven transport requires no external energy

Prostaglandins:

a. are made by enzymes known as cyclooxygenases (COX enzymes)

b. are derived from linolenic acid

c. are favored for syntheses by treatment with NSAIDs, such as aspirin or ibuprofen

d. all of the above are true

e. none of the above are true

a. are made by enzymes known as cyclooxygenases

With respect to the lactose permeate:

a. it uses energy from a proton gradient

b. it is a symport

c. it is electrogenic

d. all of the above are true

e. none of the above are true

d. all of the above are true

At the start of nerve transmission,

a. potassium gates open to attempt to restore the charge imbalance caused by opening of the sodium gates

b. the first ions to move are protons

c. the second ion to move is sodium

d. all of the above are true

e. none of the above are true

a. potassium gates open to attempt to restore the charge imbalance caused by opening of the sodium gates

Neurotransmitters:

a. travel through sodium and/or potassium gates

b. required a proton gradient

c. are protons

d. all of the above are true

e. none of the above are true

e. none of the above are true

With respect to electron transport, which of the following statements is not true?

a. electrons enter in pairs and exit singly

b. coenzyme Q acts as the traffic cop

c. oxygen is not required in the process

d. cytochrome C interacts with complex 3

c. oxygen is not required in the process

With respect to the Q cycle:

a. the first pair of electrons splits, one going to cytochrome C and the other to coenzyme Q

b. the second pair of electrons splits, one going to cytochrome C and the other to coenzyme Q

c. proton pumping occurs during the cycle

d. all of the above are true

e. none of the above are true

d. all of the above are true

With respect to oxidative phosphorylation, which of the following is not true?

a. the process requires ATP

b. the process does not have a step involving O2

c. it decreases with treatment with 2.4 dintrophenol

d. ATP synthase is located in the mitochondrial inner membrane

a. the process requires ATP

With respect to the structure of ATP synthase:

a. the "L" configuration makes ATP

b. the "O" configuration makes ATP

c. the "T" configuration makes ATP

d. all of the above are true

e. none of the above are true

c. the "T" configuration makes ATP

When repertory control exists:

a. mitochondria are resistant to 2,4 dinitrophenol

b. high NAD+ levels tend to favor electron transport

c. high ATP levels will stimulate electron transport

d. all of the above are true

c. none of the above are true

c. none of the above are true

When mitochondria get uncoupled, which of the following is not true:

a. oxygen consumption goes up

b. temperature increases

c. citric acid cycle slows

d. temperature increases

c. citric acid cycle slows

With respect to glycerolized metabolism:

a. phosphatidic acid is a precursor of sphingolipid compounds

b. glycerolipids typically contain a saturated fatty acid at position #2

c. it does not use palmitoyl-CoA and serine as precursors

d. all of the above are true

e. none of the above are true

c. it does not use palmitoyl-CoA and serine as precursors

With respect to metabolites made from cholesterol:

a. estrogens are derived from androgens

b. it includes vitamin D, but not vitamin A

c. it includes all of the steroid hormones

d. all of the above are true

e. none of the above are true

d. all of the above are true

With respect to NADH:

a. it cannot move across the mitochondrial outer membrane

b. it is needed for the citric acid cycle to function

c. it binds to the ATP synthase to provide the protons

d. all of the above are true

e. none of the above are true

e. none of the above are true

With respect to cholesterol biosynthesis:

a. it uses 5 carbon building blocks known as isoperenes

b. squalene is not a cyclic intermediate

c. it is regulated allosterically

d. all of the above are true

e. none of the above are true

d. all of the above are true

With respect to superoxide dismutase:

a. it produces superoxide

b. it uses ozone

c. it uses oxidized molecular oxygen

d. all of the above are true

e. none of the above are true

e. none of the above are true

With respect to glycerophospholipid metabolism:

a. phosphatidic acid contains two fatty acids

b. triacylglycerol lipase does not work on them

c. CDP is found in activated intermediates in their metabolsim

d. all of the above are true

e.none of the above are true

d. all of the above are true