Enzymes 2.4.1

Question 1

What are enzymes? (4 points)

Answer 1

• Biological catalysts (speed up metabolic reactions)
• Globular proteins
• Remain unchanged at the end of a reaction
• Specific

Question 2

What is the turnover number?

Answer 2

The number of reactions that an enzyme molecule can catalyse per second

Question 3

What determines the shape of an enzyme?

Answer 3

It’s tertiary/quaternary structure - this is crucial as its shape is complimentary to the substrate.

Question 4

What is the active site?

Answer 4

An indentation or cleft on the surface of the enzyme

Question 5

How is the enzymes structure stabilised?

Answer 5

Through hydrogen, ionic, and disulphide bonds.

Question 6

What causes the enzymes shape to change?

Answer 6

• Temperature and pH - affect the bonds that maintains the structure
• Genetic mutation - alters the sequence of amino acids, and therefore its structure and ability to function

Question 7

Where do enzymes work? (5 areas)

Answer 7

• Intracellular
• Extracellular (secreted from cells)
• Catabolic (break large molecules into smaller units and release energy)
• Anabolic (use energy to build larger molecules by adding units together (synthesis)
• Isomerase (some alter the substrate molecule)

Question 8

What are metabolites?

Answer 8

Reactants, intermediates, and products that are part of a metabolic pathway

Question 9

What does catalase do?

Answer 9

Ensures hydrogen peroxide is broken down to oxygen and water quickly, preventing its accumulation/toxicity

Question 10

Give an example of an extracellular enzyme

Answer 10

Fungi - release hydrolytic enzymes from their thread like hyphae d
to guest large molecules, and then absorb the products of digestion.