Which term describes a reaction that can occur without oxygen?

• A. Aerobic
• B. Anaerobic
• C. Coupled reaction
• D. Short term lactate anaerobic system

Answer: (B)

The key idea is anaerobic: it means a process can happen without oxygen, producing energy quickly when oxygen supply is limited. In muscles during intense efforts, glycolysis can proceed without oxygen, generating ATP and lactate, which is why this pathway is described as anaerobic. In contrast, aerobic processes require oxygen and occur in the mitochondria, providing more ATP but at a slower rate. A coupled reaction isn’t defined by the presence or absence of oxygen, and the short-term lactate anaerobic system refers to a broader energy-system description rather than a single reaction. So the term that best fits a reaction that can occur without oxygen is anaerobic.