Liver cells have membrane-bound organelles known as peroxisomes, and these contain the enzyme catalase. Catalase breaks down hydrogen peroxide into water and oxygen gas. A student took two liver pieces of identical size and kept one in a refrigerator at $5\,^{\circ}\text{C}$ and the other in a freezer at $-18\,^{\circ}\text{C}$. After 12 hours, both pieces were returned to room temperature and then placed in equal volumes of hydrogen peroxide. The liver that had been kept at $-18\,^{\circ}\text{C}$ gave off oxygen bubbles more quickly than the liver that had been kept at $5\,^{\circ}\text{C}$. Which statement explains why the liver that had been at $-18\,^{\circ}\text{C}$ produced bubbles of oxygen more rapidly than the liver that had been at $5\,^{\circ}\text{C}$?
- AAt $5\,^{\circ}\text{C}$ the cell surface membrane allowed water to enter cells and dilute the catalase.
- BFreezing at $-18\,^{\circ}\text{C}$ made the cell walls more permeable to hydrogen peroxide.
- CIce crystals damaged the cell membranes of the liver cells at $-18\,^{\circ}\text{C}$.
- DThe higher temperature had denatured some of the catalase.