Factors Affecting Enzymes Flashcards

All 7 cards in this deck

What is the optimum temperature of an enzyme?

The temperature at which the enzyme works fastest (has its highest rate of reaction).

What effect does increasing the temperature up to the optimum have on the rate of an enzyme-controlled reaction?

The rate increases, because molecules have more kinetic energy so there are more collisions between enzyme and substrate.

What is denaturation of an enzyme?

A permanent change in the shape of the enzyme's active site, so the substrate no longer fits and no enzyme–substrate complexes form.

What effect does increasing substrate concentration have on the rate of an enzyme-controlled reaction?

The rate increases at first, then levels off when all the active sites are occupied (the enzyme is saturated).

True or false? Enzymes are killed by high temperatures.

False. Enzymes are not alive — they are denatured, as the shape of the active site changes.

What is the optimum pH of an enzyme?

The pH at which the enzyme works fastest (highest rate of reaction).

True or false? Every enzyme has an optimum pH of 7.

False. Different enzymes have different optimum pH values, e.g. stomach protease works best at about pH 2.