Enzymes

Question 1

what is an enzyme?

Answer 1

A catalyst which speeds up chemical reactions - without themselves being changed as a result

Question 2

What are some of the roles of enzymes?

Answer 2

• Respiration
• Digestion
• Muscle & Nerve function

Question 3

Function of pepsin and trypsin?

Answer 3

Breaks down protein into amino acids

Pepsin = Stomach
Trypsin = Small intestine

Question 4

What happens to enzymes at extreme pH or temperature?

Answer 4

Enzyme may lose its 3D structure and become denatured -> inactive

Question 5

What effect does an enzyme have on the activation energy (Ea) of a reaction?

Answer 5

An enzyme decreases activation energy reducing the energy required for the reaction to occur

Question 6

What are the factors which affect rate of enzyme reaction?

Answer 6

• temperature
• pH
• enzyme conc
• substrate conc
• inhibitors & activators
• covalent modification (addition or removal of chemical groups)

Question 7

What is competitive inhibition?

Answer 7

Substrate and inhibitor compete for SAME active binding site

can overcome inhibition by increasing substrate conc

Question 8

what is non-competitive inhibition?

Answer 8

Inhibitor binds to allosteric site (another binding site on enzyme) causes conformational change to original binding site

cannot overcome inhibition by increasing substrate conc