Question

Gibberellin is the primary plant hormone that promotes elongation of the stem as a plant grows taller. GA 3-beta-hydroxylase (GA3H) is the enzyme that catalyzes the reaction by converting a precursor of gibberellin to the active form of gibberellin. A mutation in the GA3H gene results in a short plant phenotype. When a pure-breeding tall plant is crossed with a pure-breeding short plant, all offspring in the F1 generation are tall.

Describe what it means for an enzyme to catalyze a chemical reaction.

Explain why a change in an enzyme’s shape will cause it to function less effectively.

Answer 1