SB1e - Enzymes and Nutrition

Question 1

What is an enzymes?

Answer 1

it is a protein which speed up reactions by lowering the activation energy without being used up or changed themselves.

This means they can be reused again and again
* In short, enzymes are biological catalysts.

Question 2

Explain the lock and key hypothesis.

Answer 2

• Enzymes have a pocket called the active site
• Substrate molecules bind to it and are catalyzed
• In the lock and key hypothesis, the shape of the active site matches the shape of its substrate molecules - this makes enzymes highly specific.’
• Each type of enzyme can usually catalyse only one type of reaction

Question 2

What is denaturing and when does it occur?

Answer 2

Denaturing is altering the shape of the active site so that the substrate can no longer carry out its function

Enzymes denature when:
- Temperature above optimum
- pH values above and below their optimum pH

Question 2

Name the 4 enzymes.

Answer 2

Amylase
catalase
starch synthase
DNA polymerase