What happens to muscle cells if they deplete their supply of oxygen and ATP?

• A. They increase the production of creatine phosphate.
• B. They stop contracting and enter a state of rigor mortis.
• C. They switch to anaerobic metabolism, producing lactic acid.
• D. They continue aerobic respiration without any changes.

Answer: (C)

Verified step by step guidance

1. Understand the role of oxygen and ATP in muscle cell function: Oxygen is crucial for aerobic respiration, which produces ATP, the energy currency of the cell. ATP is necessary for muscle contraction and relaxation.
2. Recognize the consequences of oxygen depletion: When muscle cells lack oxygen, they cannot perform aerobic respiration efficiently, leading to reduced ATP production.
3. Explore alternative energy pathways: In the absence of sufficient oxygen, muscle cells switch to anaerobic metabolism to generate ATP. This process does not require oxygen but is less efficient and results in the production of lactic acid.
4. Consider the effects of anaerobic metabolism: The accumulation of lactic acid can lead to muscle fatigue and soreness, as it lowers the pH within the muscle cells.
5. Clarify why other options are incorrect: Creatine phosphate is a short-term energy reserve but does not increase production in response to oxygen depletion. Rigor mortis occurs post-mortem, not during oxygen depletion. Aerobic respiration cannot continue without oxygen.