A hungry yeast cell lands in a vat of grape juice and begins to feast on the sugars there, producing carbon dioxide and ethanol in the process:
C₆H₁₂O₆ + 2ADP + 2P_i + H⁺ → 2CO₂ + 2CH₃CH₂OH + 2ATP + 2H₂O
Unfortunately, the grape juice is contaminated with proteases that attack some of the transport proteins in the yeast cell membrane, and the yeast cell dies.Which of the following is the most likely cause of the yeast cell's demise?

Question

Quizplus · Accepted Answer

Without transport proteins, the yeast cell cannot import sugar from the grape juice, and thus cannot produce the energy (ATP) needed to survive. The toxic buildup of carbon dioxide and ethanol may contribute to the yeast cell's demise, but the inability to import sugar is the primary cause of its death. Diffusion of ATP out of the cell is not a likely cause of death, as ATP is produced inside the cell and used for energy within the cell.

A Hungry Yeast Cell Lands in a Vat of Grape