Exam 3

Question 1

During protein synthesis, how many phosphoanhydride bonds are hydrolyzed (broken) for each amino acid in a protein?

Answer 1

4

Question 2

Which molecule is involved with the oxidation of glucose, synthesis of fatty acids and oxidation of fatty acids?

Answer 2

acetyl-CoA

Question 3

What represents the net products of glycolysis from one molecule of glucose?

Answer 3

2 pyruvate, 2 NADH, 2 ATP

Question 4

What is the name for the process that produces ATP from ADP in glycolysis?

Answer 4

substrate-level phosphorylation

Question 5

Under anaerobic conditions in skeletal muscle, pyruvate is converted into

Answer 5

lactate

Question 6

What is an inhibitor of pyruvate dehydrogenase?

Answer 6

NADH

Question 7

What transport system moves activated fatty acids (acyl-CoA) from the cytosol to the mitochondrial matrix?

Answer 7

Carnitine shuttle

Question 8

Each round of B-oxidation of a saturated fatty acyl-CoA produces

Answer 8

1 NADH, 1 QH2, 1 acetyl-CoA

Question 9

The activation of acetyl-CoA for fatty acid synthesis is achieved by converting the acetyl-CoA into

Answer 9

malonyl-CoA

Question 10

What molecule is able to move across the mitochondrial membrane and is thus used to “transfer” acetyl-CoA from the mitochondria to the cytosol?

Answer 10

citrate

Question 11

Under anaerobic conditions, _______ is produced in the muscle and is then used by the liver for _____.

Answer 11

lactate

gluconeogenesis

Question 12

How does insulin cause an increase in the rate of glucose transport into cells?

Answer 12

recruits glucose transporters from intracellular vesicles to the cell membrane

Question 13

What hormone is most likely responsible for the body weight set-point?

Answer 13

leptin

Question 14

What aspect of brown adipose tissue is responsible for its ability to generate heat?

Answer 14

the uncoupling protein thermogenin allows fatty acid oxidation without ATP production

Question 15

When a reaction is at equilibrium, the DeltaG is equal to

Answer 15

0

Question 16

The steps in glycolysis that are different than those in gluconeogenesis are catalyzed by these enzymes

Answer 16

pyruvate kinase, phosphofructokinase, hexokinase

Question 17

To mobilize glucose from glycogen for energy, the activity of two enzymes, _____ and _____ are carefully regulated by kinases and phosphatases to ensure sufficient energy is available for use.

Answer 17

glycogen phosphorylase and glycogen synthase

Question 18

Inhibited by NADH and Succinyl-CoA

Answer 18

Alpha-ketoglutarate dehydrogenase complex

Question 19

Inhibited by Succinyl-CoA and ATP

Answer 19

Citrate synthase

Question 20

Stimulated by AMP and CoA

Answer 20

Pyruvate dehydrogenase complex

Question 21

Stimulated by ADP; inhibited by ATP

Answer 21

Isocitrate dehydrogenase

Question 22

Stimulated by Citrate

Answer 22

Acetyl-CoA carboxylase

Question 23

Lactate released from muscle converted back to glucose in liver. What is the cost of ATP of this cycle?

Answer 23

4 ATP since 2 ATP are generated in glycolysis.

Gluconeogenesis is 6 ATP.

Question 24

What is one of the major hormones that regulates gluconeogenesis?

Answer 24

Insulin. It decreases transcription of genes coding for certain gluconeogenic enzymes.

Question 25

For which genes would you expect insulin to suppress transcription?

Answer 25

Gluconeogenic enzymes:
G6P
PEPCK
Fructose,1,6-biphosphatase
Pyruvate carboxylase

Question 26

Which compound could be involved in a reaction coupled to the synthesis of ATP from ADP + Pi?

Answer 26

Reactions involving phoshphoenolypyruvate, 1,3-bisphosphoglycerate, and phosphocreatine

Question 27

ADP stimulates the activity of phosphofructokinase, yet it is a _____ of the reaction not a ______

Answer 27

product

not a reactant

Question 28

Yeast grow under anaerobic conditions and can convert pyruvate to alcohol in a process called

Answer 28

fermentation