Allosteric Modulation

Q. Feedback inhibition of enzyme is due to

1. substrate accumulation
2. structural similarity between substrate and inhibitor
3. accumulation of end product
4. accumulation of inhibitor

Q.

Can humans digest casein?

Q.

In feedback inhibition mechanism to control the rate of a metabolic pathway, the end product of the pathway acts as a

1. Competitive inhibitor

2. Irreversible inhibitor

3. Allosteric inhibitor

4. Cooperative molecule

Q. Which of these molecules act as an inducer in Lac operon?

1. Allolactose
2. Lactic acid
3. Galactose
4. Glucose

Q. In the Lac operon, the repressor protein exerts a negative effect on the expression of structural genes in the absence of inducer molecule. In case of the Lac operon, what is the inducer molecule?

1. Allolactose
2. Glucose
3. RNA polymerase
4. Galactose

Q. Is allosteric inhibition only applicable in the lock and key mechanism?
Since the induced fit theory tells that the substrate can actually induce a change in the active site of the enzyme, hence even if the inibitor attaches itself to the enzyme, the substrate can attach to it (by changing the shape of the active site).

Q. Identify the correct statement regarding enzyme inhibition.

1. Non-competitive inhibition of an enzyme can be overcomed by adding large amount of substrate.
2. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.
3. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme.
4. Non-competitive inhibitors often bind to the enzyme irreversibly.

Q. Match column I with column II and choose the correct option.
$\begin{array}{cccc}& \text{Column I}& & \text{Column II}\\ \text{(a)}& \text{Competitive inhibitor}& \text{(i)}& \text{Catalyze the joining}\\ & & & \text{of C-O, C-S, C-N, etc. bonds}\\ \text{(b)}& \text{Ligases}& \text{(ii)}& \text{Malonate}\\ \text{(c)}& \text{Most abundant protein in the animal world}& \text{(iii)}& \text{Lactose}\\ \text{(d)}& \text{Disaccharide}& \text{(iv)}& \text{Collagen}\end{array}$

1. (a) (b) (c) (d)
   (ii) (iii) (i) (iv)
2. (a) (b) (c) (d)
   (iv) (iii) (ii) (i)
3. (a) (b) (c) (d)
   (ii) (i) (iv) (iii)
4. (a) (b) (c) (d)
   (i) (ii) (iii) (iv)

Q. Which is susceptible to feedback inhibition?

1. Zymase
2. Diastase
3. Zymogen
4. Hexokinase

Q. How does competitive inhibition differ from allosteric inhibition?

Q. An example of feedback inhibition is

1. Sulpha drug on folic acid synthesis in bacteria
2. Reaction between succinic dehydrogenase and succinic acid
3. Allosteric inhibition of hexokinase by glucose 6-phosphate
4. Cyanide action on cytochrome

Q.

Which one of the following characteristics best applies to an allosteric effector?

1. Changes substrate specificity of the enzyme

2. Binds to a site on the enzyme molecule distinct from the catalytic site

3. Competes with the substrate for the catalytic site

4. Changes the nature of the product formed

Q. Feedback inhibition of enzyme is due to

1. substrate accumulation
2. structural similarity between substrate and inhibitor
3. accumulation of end product
4. accumulation of inhibitor

Q. Change of active sites which prevents the binding of substrate to enzyme and stops the reaction, is called

1. Reverse inhibition
2. Competitive inhibition
3. Allosteric inhibition
4. Non-competitive inhibition

Q. If hexokinase is blocked, how will this impact the glycolytic pathway?

1. Glycolysis would continue to occur normally
2. Glycolysis would speed up
3. Glycolysis would slow down
4. Glycolysis would stop

Q. What do you mean by competitive inhibition? How can it be prevented?

Q. The specific site of the protein which binds to the substrate to form an enzyme substrate complex is called.......... site

Q. Competitive inhibition could be reversed by increasing the concentration of ____________.

1. Substrate
2. Product
3. Coenzyme
4. Enzyme

Q. Which is susceptible to feed back inhibition?

1. Zymogen
2. Zymase
3. Diastase
4. Hexokinase

Q.

Substances, which obstruct enzyme activity are called ___.

Q. Feedback inhibition of enzyme is due to

1. substrate accumulation
2. structural similarity between substrate and inhibitor
3. accumulation of end product
4. accumulation of inhibitor

Q.

Substances, which obstruct enzyme activity are called ___.

Q. Which statement regarding enzyme inhibition is correct?

1. Competitive inhibition occurs when a substrate competes with enzyme for binding to inhibitor protein
2. Competitive inhibition occurs when the substrate and the inhibitor compete for active site on the enzyme
3. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate
4. Non-competitive inhibitors often bind to the enzyme irreversibly

Q. Product of an enzyme catalysed reaction can act as an inhibitor of the reaction. It is

1. Feedback inhibition
2. Repression
3. Non-competitive inhibition
4. Competitive inhibition

Q. In an enzymatic reaction, the activity of enzyme is altered by changing _ structure of protein. Choose the option that fills the blank correctly. a) Primary b) Tertiary c) Alpha helix d) Beta pleated

Q. Feedback inhibition is caused by blocking of enzymes by

1. Accumulated end products
2. Competitive inhibition
3. Hormones
4. Chemicals produced by hormones

Q.

Substances, which obstruct enzyme activity are called ___.

Q. IN lock and key hypothesis after the reaction the lock which is the enzyme is get modified ryt but in true things after the rxn the enzyme should not be modified it should be remainunchanged so how this hypothesis fit with enzyme action??

Q.

Which one of the following characteristics best applies to an allosteric effector?

1. Competes with the substrate for the catalytic site

2. Binds to a site on the enzyme molecule distinct from the catalytic site

3. Changes the nature of the product formed

4. Changes substrate specificity of the enzyme