Exam 5 Old

Question 1

GSK-470 is a small molecule inhibitor of pdk1 enzyme activity. Which would be a likely effect of decreased PDK1 activity

Answer 1

Increased blood glucose

Question 2

When bound to GTP, the G-alpha subunit is able to interact with

Answer 2

Adenylate cyclase

Question 3

When a person takes in more calories than they use, which of the following would show increased rates?

Answer 3

Glycolysis and glycogen synthesis

Question 4

Which statement best describes the relationship between glycogen and starch?

Answer 4

Glycogen has more branches and both glycogen and starch are degraded from nonreducing ends

Question 5

In the glycolysis pathway, the product of the GAPDH enzyme is

Answer 5

1, 3 BP

Question 6

In which of the following metabolic conversions is ATP consumed during glycolysis

Answer 6

Glucose to glucose-6-phosphate
And fructos-6-phosphate to fructose 1,6 -bisphosphate

Question 7

Which of the following is NOTa consequence of having phosphorylated glycolytic intermediate?
Phosphates help to decrease the overall free energy change for glycolytic reactions
Phosphates provide additional binding intermolecular forces with glycolytic enzymes
Phosphates help to decrease the ctivation energy for the reactions catalyzed by glycolytic enzymes
Phosphates increase the specificity of the substrate recognition by glycolytic enzymes
Phosphates are good leaving groups, allowing a release of energy when the products of their hydrolysis become more stable

Answer 7

Phosphates help to decrease the overall free energy change for glycolytic reactions

Question 8

Triose phosphate isomer are deficiency is a rare recessive disorder that can cause hemolytic anemia. I If a person has deficient triose phosphate isomerase activity, which glycolytic intermediate is likely to accumulate?

Answer 8

DHAP

Question 9

A deficiency of phosphofructokinase-1 activity would lead to an eventual accumulation of upstream and decrease of downstream glycolytic intermediates. A result of this deficient enzyme activity could be

Answer 9

A decrease in 2,3 BPG levels and subsequent increase in Hb affinity for oxygen

Question 10

Under anaerobic conditions in humans, pyruvate is converted to ___ in order to

Answer 10

Lactate; regenerate the NAD+ needed for glycolysis to continue

Question 11

Of ADP, AMP, ATP, citrate and F26BP
Which activate pfk1

Answer 11

ADP, AMP, F26BP

Question 12

Of ADP, AMP, ATP, citrate and F26BP
When PFK1 is activated allosterically, indicate whether it will shift to the relaxed or tense state, whether affinity for substrate decrease or increase, and whether the activity curve will shift left r right

Answer 12

R state
Increased affinity
Left shift in curve

Question 13

Of ADP, AMP, ATP, citrate and F26BP
Which will inhibit phosphofructokinase-1

Answer 13

ATP and citrate

Question 14

Of ADP, AMP, ATP, citrate and F26BP
When PFK1 is inhibited allosterically, indicate whether it will shift to the relaxed or tense state, whether affinity for substrate will decrease or increase, and whether the activity curve will shift right or left

Answer 14

T state
Decreased affinity
Right shift

Question 15

When a person uses more calories than they take in, which of the following would show increased rate?

Answer 15

Gluconegenisis and glycogen degradation

Question 16

In the glycolysis pathway, the product of PGM enzyme is

Answer 16

2PG

Question 17

Phosphoglycerate kinase deficit is an x-linked recessive disorder that can cause hemolytic anemia. If a person has deficient phosphoglycerate kinase activity, which glycolytic intermediate is likely to accumulate

Answer 17

1,3 BPG

Question 18

The standard free energy change for the transfer of electrons from FADH2, to one of the partners below is -52.1kJ/mol. What is the identity of the partner?

Answer 18

Cytochrome c

Question 19

In the following two half reactions are paired together, __would spontaneously accept electrons from ___

Answer 19

NO3-; QH2

Question 20

Which of these describes a role of NAD+ in the pyruvate dehydrogenase complex set of reactions?

Answer 20

Oxidizes FADH2

Question 21

Which of these molecules inhibits the pyruvate dehydrogenase complex?

Answer 21

Acetyl-CoA

Question 22

In humans, what is pyruvate converted to under anaerobic conditions?

Answer 22

Lactic acid

Question 23

In the diagnosis of cancer, 2-fluro-2-deoxyglucose is used as a tracer for PET scanning. Explain what makes this molecule useful for diagnosis and why glucose itself cannot be used

Answer 23

It is a modified glucose used to locate cancer in PET scanning, it cannot be made in F6P so it will accumulate, and glycolysis will not continue. glucose itself cannot be used because cancer uses glucose as an energy source to continue to grow

Question 24

Which of these describes a role of FAD in the pyruvate dehydrogenase complex set of reactions

Answer 24

Oxidizes lipomide

Question 25

how many electrons are accepted by NADH and FADH2 in four turns of the citrate cycle

Answer 25

32

Question 26

If aconitase is inhibited, it’s substrate ___ would accumulate

Answer 26

Citrate

Question 27

The reactions that recreate citrate cycle intermediates are called ____. These reactions are needed because

Answer 27

Anaplerotic; the citrate cycle is an amphibolic pathway

Question 28

Which three enzymes yield CO2 as glucose is completely oxidized through glycolysis, the pyruvate dehydrogenase complex, and the citrate cycle?

Answer 28

Isocitrate——> alpha-ketogluterate
Alpha-ketogluterate——-> succinyl CoA
Pyruvate——> hydroxyethyl-TPP?

Question 29

Account for the 24 electrons removed from glucose through glycolysis, the pyruvate dehydrogenase complex, and citrate cycle. Do this by providing the NADH and FADH2 yield from each pathway and briefly explaining how these correlate to the removal of 24 electrons from glucose

Answer 29

Glycolysis: 2 NADH remove 4 electrons from glucose
PDH complex: 2 NADH removes 4 electrons from glucose
Citrate cycle: 6 NADH and 2 FADH2 remove 16 electrons from glucose

Question 30

Account for the 32 ATP yielded through glycolysis, the pyruvate dehydrogenase complex, and the citrate cycle

Answer 30

Glycolysis: 7 ATP (2 ATP, 2 NADH)
PDH complex: 5 ATP (2 NADH)
Citrate cycle: 20 ATP (6 NADH, 2 FADH2, 2 GTP)