Final answer:
Catalase in yeast cells is responsible for decomposing hydrogen peroxide into water and oxygen, thus protecting the cell from oxidative damage.
Step-by-step explanation:
Catalase is an enzyme found in yeast cells that facilitates the decomposition of hydrogen peroxide into water and oxygen. This function is crucial as hydrogen peroxide (H₂O₂) is a reactive oxygen species that can potentially harm cells by oxidizing biomolecules. Catalase helps in protecting the cell by breaking down hydrogen peroxide, which is a byproduct of various metabolic processes, particularly those involved in aerobic respiration. Aerobic organisms use catalase to detoxify reactive oxygen species and maintain cellular health. Therefore, the correct answer to the given multiple-choice question is d) Hydrogen peroxide decomposition.