Cellular respiration can be studied in isolated mitochondria by measuring the co
ID: 60149 • Letter: C
Question
Cellular respiration can be studied in isolated mitochondria by measuring the consumption of oxygen under different conditions. If sodium malonate to a concentration of 0.01 M is added to an actively respiring preparation of mitochondria using pyruvate as a fuel source, respiration soon ceases and a metabolic
intermediate accumulates. a. What is the structure of this intermediate? b. Explain why it accumulates. c. Explain why the consumption of oxygen ceases. d. Aside from the removal of the malonate, how could you overcome the inhibition of respiration?
Explanation / Answer
The intermediate formed is succinate.Actually sodium malonate is a competitive inhibitor of succinate dehydrogenase enzyme used in Kreb cycle. This results in block in succinate. Which finally causes block in NADH formation. Without NADH oxidative phosphorylation will not occur and oxygen will not be used up. If succinate is supplied, then this inhibition can be overcome..