Question

question 19 of 22
what happens to an enzyme if the temperature varies too far from the enzymes optimum (or best) temperature?
a. the enzyme binds to a different substrate.
b. the enzyme causes the reaction to take place too quickly.
c. the enzyme changes shape and no longer binds to the substrate.
d. the enzyme is unaffected by changes in temperature.

Explanation:

Enzymes have an optimal temperature range. When temperature varies too far from this optimum, the enzyme's structure (shape) is disrupted (denatured). This change in shape means it can no longer bind to its specific substrate as the active site (where substrate binds) is altered. Option A is incorrect as enzyme - substrate specificity is based on shape, not temperature - induced substrate change. Option B is wrong because if the enzyme is denatured (at extreme temperatures), it doesn't function (so reaction doesn't occur too quickly). Option D is incorrect as enzymes are affected by temperature (denaturation at extremes).

Answer:

C. The enzyme changes shape and no longer binds to the substrate.