Metabolic Pathways

Question 1

What controls metabolic pathways

Answer 1

Enzymes

Question 2

The following statements refer to enzyme inhibition.

1. Bind to active site on enzyme
2. Bind away from active site
3. Reversed by increasing substrate concentration
4. Cannot be reversed by increasing substrate concentration

Which option below correctly identifies a competitive inhibitor?

Answer 2

1 and 3

Question 3

The items below refer to properties of anabolic and catabolic reactions within a metabolic pathway.

1. Requires Energy
2. Building up
3. Breaking down
   Which of these refer to a catabolic reaction?

Answer 3

3

Question 4

Which of the following will NOT control the rate of enzyme activity?

pH
Temperature
Concentration of substrates
Time it takes to complete the pathway

Answer 4

Time it takes to complete the pathway

Question 5

What is a catabolic reaction

Answer 5

Breakdown of large molecules into small molecules releasing energy

Question 6

Proteins embedded within the membrane have a variety of functions. One of these functions is a pore.

What is the function of a pore

Answer 6

Allows molecules to pass through

Question 7

When a substrate binds to an enzyme, the active site changes shape to better fit the substrate.

Which of these terms describes this process

Answer 7

Induced fit

Question 8

When an end-product in a metabolic pathway reaches critical concentration, it inhibits an earlier enzyme blocking the pathway.

This type of inhibition is known as…

Answer 8

Feedback inhibition

Question 9

What is the meaning of the term ‘activation energy’ in relation to chemical reactions.

Answer 9

The minimum amount of energy required for a chemical reaction to start

Question 10

Proteins embedded within the membrane have a variety of functions. One of these functions is an enzyme.

What is the function of an enzyme embedded within the membrane?

Answer 10

Catalyses chemical reaction

Question 11

The following statements refer to enzyme inhibition.

1. Bind to active site on enzyme
2. Bind away from active site
3. Reversed by increasing substrate concentration.
4. Cannot be reversed by increasing substrate concentration

Which statements correctly identify a non-competitive inhibitor?

Answer 11

2 and 4

Question 12

What is the impact of an enzyme on the activation energy required by a chemical reaction?

Answer 12

Decreases (lowers)

Question 13

Which of the following represent pathways present in a metabolic pathway?

1. Reversible steps
2. Irreversible steps
3. Alternative routes

Answer 13

1, 2 and 3

Question 14

correctly describe the affinity of a substrate molecule and a product molecule on the active site of an enzyme?

Answer 14

Substrate = high
Product = low

Question 15

Which of the following represents the control of a metabolic pathway?

Absence of key enzymes
Presence of key enzymes
Both presence and absence of key enzymes
All enzymes must be present

Answer 15

Both presence and absence of key enzymes

Question 16

The items below refer to properties of anabolic and catabolic reactions within a metabolic pathway.

1. Requires energy
2. Building up
3. Breaking down

Which of these refer to an anabolic reaction?

Answer 16

1 and 2

Question 17

describe an anabolic reaction

Answer 17

Building up of large molecules from small molecules requiring energy

Question 18

The following refer to functions of proteins.

1. Pores
2. Pumps
3. Enzymes

Which refer to the function(s) of proteins embedded within the membrane?

Answer 18

1, 2 and 3

Question 19

describe the meaning of the term ‘induced fit’

Answer 19

The active site changing shape to better fit the substrate