Which of the following statements is true of most cellular redox reactions?

• A. They always require the presence of oxygen.
• B. They involve the transfer of electrons from a donor to an acceptor.
• C. They result in the production of ATP directly.
• D. They occur only in the mitochondria of eukaryotic cells.

Answer: (B)

Verified step by step guidance

1. Understand the concept of redox reactions: Redox reactions involve the transfer of electrons between two species. The species that loses electrons is oxidized, and the species that gains electrons is reduced.
2. Identify the role of oxygen in redox reactions: While oxygen is a common oxidizing agent, not all redox reactions require oxygen. Therefore, the statement that redox reactions always require oxygen is not true.
3. Consider the production of ATP: While some redox reactions are involved in processes that produce ATP, such as cellular respiration, not all redox reactions directly result in ATP production.
4. Examine the location of redox reactions: Redox reactions can occur in various parts of the cell, not just in the mitochondria. For example, they also occur in the cytoplasm during glycolysis.
5. Conclude with the correct statement: The most accurate statement about cellular redox reactions is that they involve the transfer of electrons from a donor to an acceptor, which is a fundamental characteristic of redox processes.