Enzyme

The solid line on the graph represents the product formed over time for a reaction in a cell.

Which other line represents the effect of adding the enzyme for this reaction?

• A

• B

• C

• D

What is the factor limiting the rate in region X?

• substrate concentration

• enzyme concentration

• temperature

• number of active sites

What would limit the initial rate of reaction at point X?

• enzyme concentration

• pH

• substrate concentration

• temperature

• A

• B

• C

• D

Which statements describe some enzyme actions?

1. Enzymes hold reacting molecules so that their reactive groups are close together.

2. In an enyzme-catalysed reaction, more molecules have sufficient energy to react than without enzyme.

3. Reactions catalysed by enzymes take place at a lower temperature than they would without the enzyme.

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

• A

• B

• C

• D

• Enzymes are fibrous proteins that catalyse reactions inside cells.

• True

• False

What is the optimal pH for this enzyme?

• 6

• 10

• 9

• 7

Most enzymes have the ending:

• -ose

• -ase

• -ic acid

• -ate

What factors would affect the reaction rate?

(multiple correct answer)

• temperature

• pH

• concentration of enzymes

• concentration of substrate