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Question 01

Embedded in the inner membrane of the mitochondrion are:

a) the enzymes of the tricarboxylic acid cycle (Krebs' cycle)

b) the components of the electron transport chain

c) glycogen molecules

d) triacylglycerol molecules

e) GLUT4 molecules

Question 02

Glucose enters muscle cells mostly by:

a) simple diffusion

b) facilitated diffusion using a specific glucose transporter

c) co-transport with sodium

d) co-transport with amino acids

e) active transport

Question 03

Aerobic resynthesis of ATP occurs:

a) in the mitochondria in a process called glycogenolysis

b) in the mitochondria in a process called oxidative phosphorylation

c) in the cytosol

d) in the sarcoplasmic reticulum

e) only in Type I muscle fibres

Question 04

The synthesis of glucose from lactate, glycerol, or amino acids is called:

a) glycogenolysis

b) glycolysislipolysis

c) lipolysis

d) gluconeogenesis

e) transamination

Question 05

The major source of carbohydrate in a typical Western diet is:

a) starch

b) cellulose

c) glycogen

d) sucrose

e) saccharin

Question 06

Liver glycogen breakdown is stimulated by:

a) insulin

b) glucagon

c) adrenaline

d) both (a) and (b)

e) both (b) and (c)

Question 07

The process of breaking down triacylglycerol into free fatty acids and glycerol is called:

a) beta oxidation

b) lipogenesislipolysis

c) lipolysis

d) both (a) and (c) are correct

e) none of the above are correct

Question 08

Most of the free fatty acids are transported in the blood:

a) inside the red blood cells

b) as lipoproteins

c) combined with glucose

d) bound to albuminbound to antibodies

e) bound to antibodies

Question 09

Fatty acids are transported into the mitochondria bound to:

a) thiokinasecoenzyme A (CoA)

b) coenzyme A (CoA)

c) acetyl-CoA

d) carnitine

e) phosphate

Question 10

The Β-oxidation of a molecule of palmitic acid, CH₃(CH₂)₁₄CO₂H:

a) yields 8 molecules of acetyl-CoA and some ATP and water

b) yields 16 molecules of acetyl-CoA only

c) yields carbon dioxide and water only

d) does not involve oxygen

e) uses more ATP than it generates

Question 11

Which of the following releases most energy when completely oxidised in the body?

a) one gram of glucose

b) one gram of palmitic acid

c) one gram of leucine

d) one gram of alcohol

e) one gram of protein

Question 12

When branched chain amino acids are deaminated in muscle, the ammonia produced is mostly:

a) converted into arginine and released from the muscle

b) converted into alanine and glutamine and released from the muscle

c) converted into urea and released from the muscle

d) used to synthesise purines and pyrimidines in the muscle

e) oxidised to form nitric oxide

Question 13

Which of the following promotes glucose and amino acid uptake by muscle?

a) adrenaline

b) insulin

c) glucagon

d) cortisol

e) glycogen

Question 14

During exercise, adrenaline secretion from the adrenal glands is stimulated by:

a) increased plasma glucose

b) increased plasma fatty acids

c) increased plasma ACTH

d) increased sympathetic nerve activity

e) negative feedback

Question 15

Within the inner matrix of the mitochondrion are:

a) the enzymes of the tricarboxylic acid cycle (Krebs' cycle)

b) the components of the electron transport chain

c) glycogen molecules

d) the enzymes of gluconeogenesis

e) the enzymes creatine kinase and carnitine acyl transferase 1

Question 16

How many CO₂ and ATP molecules are formed during one complete turn of the tricarboxylic acid cycle (Krebs' cycle)?

a) 2CO₂ and 2ATP

b) 2CO₂ and 16ATP

c) 2CO₂ and 12ATP

d) 2CO₂ and 1ATP

e) 1CO₂ and 5ATP

Question 17

Oxygen is used:

a) in glycolysis

b) in the conversion of fatty acids to acetyl CoA

c) in the tricarboxylic acid cycle (Krebs' cycle)

d) in glycogenolysis

e) in Type I fibres only

Question 18

Which of the following is not a true statement?

a) muscle glycogen is broken down enzymatically to glucose-1-phosphate

b) elite endurance runners have a high proportion of Type I fibres in their leg muscles

c) liver glycogen is important in the maintenance of the blood glucose concentration

d) insulin promotes glucose uptake by all tissues in the body

e) glucagon has generally antagonistic actions to those of insulin

Question 19

The oxidative deamination of the amino acid alanine in muscle produces:

a) one molecule of pyruvic acid and a molecule of ammonia

b) one molecule of pyruvic acid and a molecule of carbon dioxide

c) one molecule of pyruvic acid and another amino acid

d) one molecule of pyruvic acid and a molecule of water

e) one molecule of pyruvic acid and a molecule of urea

Question 20

Substrate-level phosphorylation differs from oxidative phosphorylation in that:

a) substrate-level phosphorylation involves the transfer of electrons

b) substrate-level phosphorylation only occurs in the cytosol

c) oxidative phosphorylation only occurs in the cytosol

d) oxidative phosphorylation involves the transfer of electrons

e) GTP is always involved in substrate-level phosphorylation

Question 21

Which of the following statements is false?

a) phosphofructokinase is the rate limiting enzyme in glycolysis

b) phosphorylase activity is higher in Type II fibres than in Type I fibres

c) endurance training increases the amount of TCA cycle enzymes in muscle

d) oxygen is consumed in the TCA cycle

e) the heart can oxidise lactate

Question 22

Pairs of electrons carried in the form, FADH₂ and NADH+H, collectively contain enough free energy to rephosphorylate:

a) 6 ATP

b) 5 ATP

c) 4 ATP

d) 3 ATP

e) none of the above are correct

Question 23

How many ATP molecules can be derived from each molecule of acetyl CoA that enters the Krebs' Cycle?

a) 6

b) 12

c) 18

d) 38

e) 39

Question 24

Muscle and liver glycogen stores in a well nourished athlete would be sufficient to sustain approximately how many minutes of submaximal exercise (if this were the only energy source used)? The exercise is club level marathon pace.

a) 30 minutes

b) 90 minutes

c) 180 minutes

d) 210 minutes

e) 300 minutes

Question 25

Approximately how much energy is liberated when one gram of carbohydrate is completely oxidised?

a) 4 kJ

b) 8 kJ

c) 16 kJ

d) 24 kJ

e) 38 kJ

Question 26

Resting oxygen uptake for a 70 kg person is approximately:

a) 1.0 l.min^-1

b) 2.5 ml.min^-1

c) 0.25 l.min^-1

d) 45 ml.min^-1

e) none of the above

Question 27

The respiratory exchange ratio (RER) is the ratio of:

a) volume of oxygen consumed ÷ volume of carbon dioxide produced

b) volume of carbon dioxide produced ÷ volume of oxygen consumed

c) volume of oxygen produced ÷ volume of carbon dioxide consumed

d) volume of oxygen consumed ÷ body mass

e) volume of oxygen consumed ÷ lung ventilation

Question 28

Which of the following factors stimulate insulin secretion?

a) a rise in the blood glucose concentration

b) a rise in the blood amino acid concentration

c) a rise in the blood adrenaline concentration