Unit 2 - Enzymes

Question 1

What does a substrate need to have in order to bind with an active site

Answer 1

Complementary shape
Opposite charges to the active site

Question 2

How does change in pH alter the rate of the reaction

Answer 2

Enzymes have an optimum pH (usually around 7 with a working range from 5-9), where the enzyme is most active. This may change in certain conditions, such as pepsin which has an optimum of 2.

Question 3

Properties of enzymes

Answer 3

Complementary active site to shape of substrate
High turnover no.
Ability to reduce activation energy
Left unchanged after reaction

Question 4

What are enzymes affected by

Answer 4

Temperature
pH
Enzyme conc.
Substrate conc.

Question 5

What is the lock and key hypothesis

Answer 5

Shape of active site caused by sequence of amino acids (specific tertiary structure - 3D)

Question 6

How are enzymes broken down?

Answer 6

Enzyme + substrate (E + S) —>
enzyme substrate complex (ESC) —>
enzyme product complex (EPC) —>
Enzyme and product (E + P)

Question 7

Digestion of starch

Answer 7

Starch + amylose –> maltose
Occurs in mouth (saliva) and small intestine (pancreatic juice)
Maltose + maltase –> glucose (absorbed directly into bloodstream)
Occurs in small intestine