Tutorial Practice Questions - Week 10 - Introduction to Metabolism

Question 1

1. Rapid fine control of enzyme activity is important to regulate metabolic pathways,
   select two ways to achieve that:
   a. Covalent modification via phosphorylation/dephosphorylation
   b. Hormonal regulation
   c. Allosteric regulation via feedback inhibition
   d. Synthesis of more enzyme via gene expression

Answer 1

a, c

Question 2

2. Slow coarse control of enzyme activity is important to regulate metabolic pathways,
   name two ways to achieve that:
   a. Changes in substrate concentration
   b. Changes in energy status
   c. Synthesis of regulatory enzymes via gene expression
   d. Spatial segregation of enzymes/substrates via compartmentation

Answer 2

c, d

Question 3

3. Catabolic pathways often:
   a. Are oxidative
   b. Synthesise ATP
   c. Consume ATP
   d. Are reductive
   e. Involve the synthesis of larger molecules
   f. Involve the degradation of macromolecules to smaller molecules

Answer 3

a, b, f

Question 4

4. Which enzyme exerts the most control on glycolysis?
   a. Hexokinase
   b. Phosphofructokinase-1
   c. glucose-6-phosphatase
   d. aldolase

Answer 4

b

Question 5

5. During the second half of glycolysis, what occurs?
   a. ATP is used
   b. Fructose is split in two
   c. ATP is obtained
   d. Glucose becomes fructose

Answer 5

c

Question 6

6. What is removed from pyruvate during its conversion into an acetyl group?
   a. oxygen
   b. ATP
   c. B vitamin
   d. carbon dioxide

Answer 6

d

Question 7

How many rounds of the TCA cycle are required to catabolise 1 molecule of glucose?

Answer 7

2

Question 8

How many NADH molecules are produced on each turn of the TCA cycle?

Answer 8

3

Question 9

What is the yield of ATP molecules per molecule of glucose in glycolysis?

Answer 9

2

Question 10

What is the yield of ATP molecules per molecule of glucose if fully oxidised in aerobic cells?

Answer 10

32