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Answer the following questions from your knowledge of respiration - Leaving Cert Biology - Question c - 2016
Question c
Answer the following questions from your knowledge of respiration. (i) Name the 3-carbon molecule that is an intermediate compound in both aerobic and anaerobic res... show full transcript
Worked Solution & Example Answer:Answer the following questions from your knowledge of respiration - Leaving Cert Biology - Question c - 2016
Step 1
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Step 3
What happens to the intermediate compound referred to in (i) above when oxygen is available and used in the breakdown of glucose?
Answer
When oxygen is available, pyruvate undergoes oxidative decarboxylation. It is converted into acetyl-CoA, which then enters the mitochondria for further processing in the Krebs cycle. In this cycle:
- Krebs cycle: Carbon dioxide (CO₂) is produced, and ATP/NADH is generated during the cycle.
- Electron transport system: Protons (H⁺ ions) combine with oxygen (O₂) or electrons. The electrons combine with O₂ to form water and the energy released from the process is used to produce ATP from ADP plus inorganic phosphate (P).
Step 4
What is produced from the intermediate compound referred to in (i) above when oxygen is not available?
Answer
*1. In muscle: When oxygen is not available, pyruvate is converted into lactic acid (or lactate). *2. In yeast: In the absence of oxygen, pyruvate is converted to ethanol and carbon dioxide.