Biochemistry Multiple Choice Questions on “Analysis of Metabolic Control”.
1. Flux control coefficient measures the ____________
A. Steady state change
B. pH change
C. Temperature change
D. Hormonal change
Answer: A
Clarification: Flux control coefficient relatively measures of how much a perturbation affects a system variable flux.
2. What is the relation between elasticity coefficient, flux coefficient and response coefficient?
A. R = C.ε
B. R = C⁄ε
C. R = ε⁄C
D. ε = C.R
Answer: A
Clarification: R = C.ε, where R=response coefficient, C = flux coefficient and ε=elasticity coefficient.
3. Which of the following is a measure of the effect of an enzyme’s concentration on flux through a multi-enzyme pathway?
A. Response coefficient
B. Elasticity coefficient
C. Flux control coefficient
D. Metabolic control
Answer: C
Clarification: Elasticity coefficient is a measure of how responsive the enzyme is to changes in the concentration of a metabolite.
An expression for the experimentally determined change in flux through a pathway in response to a regulatory hormone or second messenger is the response coefficient.
4. Which of the following is a measure of how responsive the enzyme is to changes in the concentration of a metabolite?
A. Response coefficient
B. Elasticity coefficient
C. Flux control coefficient
D. Metabolic control
Answer: B
Clarification: Flux control coefficient is a measure of the effect of an enzyme’s concentration on flux through a multi-enzyme pathway.
An expression for the experimentally determined change in flux through a pathway in response to a regulatory hormone or second messenger is the response coefficient.
5. An expression for the experimentally determined change in flux through a pathway in response to a regulatory hormone or second messenger.
A. Response coefficient
B. Elasticity coefficient
C. Flux control coefficient
D. Metabolic control
Answer: A
Clarification: Flux control coefficient is a measure of the effect of an enzyme’s concentration on flux through a multi-enzyme pathway.
Elasticity coefficient is a measure of how responsive the enzyme is to changes in the concentration of a metabolite.
6. Which of the following statements about the control of glycogen synthesis from blood glucose in myocytes is incorrect?
A. Insulin affects three of five steps in this pathway
B. The effects on transport and hexokinase activity increase the flux towards glycogen
C. The change in glycogen synthase activity increases the flux towards glycogen
D. Hexokinase enzyme is involved
Answer: C
Clarification: The change in glycogen synthase activity decreases the flux towards glycogen.
7. Some regulated enzymes control the flux through a pathway, this activity is ___________
A. Regulation
B. Control
C. Metabolism
D. Anabolism
Answer: B
Clarification: Some regulated enzymes control the flux through a pathway, this activity is control.
8. Some regulated enzymes rebalance the level of metabolites in response to the change in flux, this activity is ___________
A. Regulation
B. Control
C. Metabolism
D. Anabolism
Answer: A
Clarification: Some regulated enzymes rebalance the level of metabolites in response to the change in flux, this activity is regulation.
9. Metabolic control analysis does not suggest that ___________
A. When the blood glucose level rises, insulin acts in muscle to increase glucose transport into cells by bringing GLUT4 to the plasma membrane
B. When the blood glucose level rises, insulin acts in muscle to induce the synthesis of PFK-1
C. When the blood glucose level rises, insulin acts in muscle to activate glycogen synthase by covalent alteration
D. When the blood glucose level rises, insulin acts in muscle to induce the synthesis of hexokinase