OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Which part of the yeast cell is involved in cellular respiration?

1. Nucleus

2. Cytoplasm

3. Cell wall

4. Cell membrane

The correct answer is: Cytoplasm

The cytoplasm is the correct choice because it is the site where glycolysis occurs, which is the first stage of cellular respiration. In yeast cells, as in many other eukaryotic cells, glucose is broken down in the cytoplasm to produce pyruvate, generating a small amount of ATP in the process. This is essential for the cell to obtain energy for various metabolic processes. While the nucleus contains the genetic material and is involved in regulating cellular activities, it does not directly participate in the process of cellular respiration. The cell wall provides structure and protection to the cell but does not play a role in energy production. The cell membrane is crucial for regulating what enters and exits the cell, but like the nucleus and cell wall, it does not directly facilitate the reactions involved in cellular respiration. Thus, the cytoplasm's role in housing metabolic pathways makes it the key location for cellular respiration in yeast.