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Semester 1- MGD > Enzyme Activity > Flashcards

Flashcards in Enzyme Activity Deck (17)
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1
Q

What is activation energy?

A

The minimum energy the substrates must have to allow the reaction to occur

2
Q

What happens when the temperature is increased in an enzyme catalysed reaction?

A

The number of molecules with the activation energy is increased.

3
Q

What happens when the concentration of the substrates is increased?

A

Increases the chance of molecular collisions so rate of reaction increases

4
Q

What is the function of an enzyme?

A

A biological catalyst that increases the rate of reaction by lowering the activation energy.

5
Q

List 3 properties of an enzyme

A

Highly-specific
Unchanged after the reaction
Do not affect reaction equilibrium
Increase rate of reaction

6
Q

What is an active site?

A

The area of an enzyme where substrates bind and the chemical reaction occurs.

7
Q

How is an enzyme able to be specific?

A

The active site will be a complementary shape to a specific substrate

8
Q

What is the optimum temperature for a human enzyme?

A

37 degrees Centigrade

9
Q

What is the optimum pH for a human enzyme?

A

Varies depending on where it works in the body

10
Q

What does the Michaelis- Menten Model propose?

A

A complex between the substrate and enzyme is a necessary intermediate

11
Q

What is the definition of Vmax?

A

The maximum rate of a reaction when all enzyme active sites are saturated

12
Q

What is the definition of Km?

A

The substrate concentration that gives half the maximum velocity of a reaction

13
Q

What does Km give a measure of?

A

The affinity of an enzyme for its substate

14
Q

What is an enzyme inhibitor?

A

Molecules that slow down or prevent an enzyme reaction

15
Q

Describe the actions of a competitive enzyme inhibitor? (+ effect on Km and Vmax)

A

A molecule with a similar shape to the substate binds to the active site of an enzyme instead of the substate. There is no effect on the Vmax but the Km increases.

16
Q

Describe the actions of a non-competitive enzyme inhibitor? (+ effect on Km and Vmax)

A

A molecule will bind at an alternative site on the enzyme (NOT the active site) to change the shape of the enzyme so the substate can no longer bind. Vmax is decreased as the enzyme number is decreased. Km stays the same

17
Q

In an enzyme catalysed reaction, what is the transition state?

A

A high energy intermediate that lies between the substrates and the product