ALL MCQS

Question 1

What is an incorrect statement about biological redox reactions?

Answer 1

B. Redox reactions are not catalyzed by kinase enzymes, which are involved in phosphorylation.

Question 2

Which statement is INCORRECT (energy related)?

Answer 2

D. Enzymes do not provide energy to make unfavorable reactions occur; they lower activation energy.

Question 3

Which statement is CORRECT q3?

Answer 3

A. In catabolism, large molecules are broken down to release energy.

Question 4

Which statement is INCORRECT Q4?

Answer 4

D. Most vitamins cannot be synthesized in the body; they must be obtained from the diet.

Question 5

GLUCOSE IS:

Answer 5

C. Essential for red blood cells as fatty acids cannot cross the cell membrane.

Question 6

What are two key features of the coenzyme NAD+?

Answer 6

C. NAD+ can be in two forms and can carry electrons and hydrogen ions (H+).

Question 7

What does digestion of carbohydrates involve?

Answer 7

D. Hydrolysis of glycosidic bonds in large polysaccharides to produce smaller oligosaccharides.

Question 8

Which is NOT involved in glucose absorption from the gastrointestinal tract?

Answer 8

A. Facilitative transport through SGLT1 is not the correct mechanism for moving glucose out of epithelial cells.

Question 9

What is a proposed reason glucose is the preferred fuel for the brain?

Answer 9

C. Brain cells have limited access to fatty acids circulating in the blood.

Question 10

Which statement about using fatty acids as a fuel molecule is CORRECT?

Answer 10

A. Fatty acids are the preferred manner to store energy because they require less space than sugars.

Question 11

What are chylomicrons involved in?

Answer 11

C. Chylomicrons are involved in the transport of fatty acids around the body after absorption.

Question 12

Which statement is INCORRECT about lipase enzymes?

Answer 12

B. Lipase enzymes cleave the ester bonds, not the glycerol, to release fatty acids.

Question 13

Which statement is INCORRECT about lipoproteins?

Answer 13

D. Lipoproteins are distinguished by the type of apolipoproteins on their surface, not the type of TAG.

Question 14

How is fatty acyl-CoA transported into the mitochondrial matrix for β-oxidation?

Answer 14

D. Conversion into fatty acyl-carnitine in the intermembrane space and back to fatty acyl-CoA in the matrix.

Question 15

What do the first three reactions of β-oxidation involve?

Answer 15

A. The rearrangement of the bond between the α and β carbons.

Question 16

Which statement is INCORRECT about the oxidation steps in β-oxidation?

Answer 16

B. The oxidation steps in β-oxidation do require coenzymes NAD+ and FAD.

Question 17

What are the products of the complete oxidation of myristate (C14:0)?

Answer 17

B. 7 acetyl-CoA + 6 NADH + 6 FADH2 + 6H+.

Question 18

What is the energy source in the conversion of succinyl-CoA to succinate?

Answer 18

B. The energy comes from the cleavage of Co-A from the succinyl-CoA.

Question 19

Which statement about the citric acid cycle is INCORRECT?

Answer 19

C. Acetyl-CoA does not need to be activated to enter the citric acid cycle.

Question 20

How does carbon enter and exit the citric acid cycle?

Answer 20

B. Carbon enters as acetyl-CoA and exits as carbon dioxide.

Question 21

What is a likely consequence of inhibiting the citric acid cycle?

Answer 21

A. A decrease in the amount of NAD in its reduced form.

Question 22

Which statement is INCORRECT about endopeptidases?

Answer 22

D. Endopeptidases cannot hydrolyze peptide bonds between any two amino acids, they have specificity.

Question 23

What does protein digestion involve?

Answer 23

C. Hydrolysis of peptide bonds by proteases.

Question 24

Which one of the following statements is CORRECT regarding deamination?

Answer 24

A. Deamination can occur through a transamination reaction transferring an amino group to a keto acid.

Question 25

In a transamination reaction, what is the carbon substrate without nitrogen?

Answer 25

B. A keto acid.

Question 26

What are the two energetic gradients resulting from the proton gradient across the inner mitochondrial membrane?

Answer 26

C. A chemical/pH gradient and an electrical gradient.

Question 27

What does the chemiosmotic theory for ATP synthesis describe?

Answer 27

B. The coupling of the electron transport chain and ATP synthesis by ATP synthase.

Question 28

Where is the electron transport chain located?

Answer 28

C. Inner mitochondrial membrane.

Question 29

What do carriers in the electron transport chain undergo?

Answer 29

A. Undergo reversible redox reactions.

Question 30

What is the succinate dehydrogenase enzyme shared between?

Answer 30

D. The citric acid cycle and the electron transport chain.

Question 31

What is a possible route for electrons in the electron transport chain?

Answer 31

D. FADH2 ➔ Complex II ➔ CoQ ➔ Complex III ➔ Cyt C ➔ Complex IV ➔ H2O.

Question 32

What happens on exposure to light with artificial liposomes containing bacteriorhodopsin and ATP synthase?

Answer 32

B. ATP is made using the proton gradient generated by bacteriorhodopsin.

Question 33

Where is the FO component of the F1FO-ATP synthase located?

Answer 33

A. Is in the inner mitochondrial membrane.

Question 34

Which one of the following statements about the F1FO-ATP synthase is INCORRECT?

Answer 34

C. Energized substrates are not required for substrate-level phosphorylation to occur in the F1FO-ATP synthase.

Question 35

Which statement concerning stored triacylglycerol (TAG) is CORRECT?

Answer 35

B. Mobilization of stored triacylglycerol is stimulated by adrenaline and glucagon.

Question 36

Which glucose transporter is responsible for insulin-stimulated glucose uptake in muscle and adipose tissue?

Answer 36

D. GLUT4.

Question 37

Which tissue predominantly uses fatty acids as the primary fuel source under resting conditions?

Answer 37

B. Skeletal muscle.

Question 38

Which statement concerning glycogen metabolism is INCORRECT?

Answer 38

A. Glycogen is stored, not circulating in the blood.

Question 39

Which statement concerning glycogenolysis is INCORRECT?

Answer 39

C. Glycogenolysis is stimulated by glucagon, not insulin.

Question 40

Which molecule is NOT a substrate for gluconeogenesis?

Answer 40

B. Citrate.

Question 41

Which statement regarding glucose-6-phosphatase is CORRECT?

Answer 41

D. Glucose-6-phosphatase is essential for the conversion of glucose 6-phosphate to glucose for release during glycogenolysis.

Question 42

Which statement about starvation is INCORRECT?

Answer 42

A. Glucagon, not insulin, activates fuel mobilization pathways during starvation.

Question 43

Which statement is INCORRECT regarding adipose tissue during starvation?

Answer 43

C. Adipose tissue does not provide fatty acids for the brain during starvation, as the brain uses glucose or ketone bodies.