The breakdown of pyruvate to give carbon dioxide, water and energy takes place in (a) cytoplasm. (c) chloroplast. (b) mitochondria. (d) nucleus.


-Priyanti, Subject Matter Expert at Edumarz

Solution:  b) Mitochondria

The formation of pyruvate from glucose (glycolysis), during respiration, is an anaerobic process and is carried out in the cytoplasm. However, the subsequent conversion of pyruvate to carbon dioxide, water and energy has to occur in the mitochondria as the reaction is aerobic in nature. The mechanism in which pyruvate participates in the mitochondria is known as the Krebs Cycle (or TCA cycle), generating energy in the form of adenosine triphosphate (ATP). In this, pyruvate is converted to acetyl CoA, which subsequently enters the TCA cycle. Pyruvate is also converted to oxaloacetate in an anaplerotic reaction consequently replenishing the TCA cycle intermediates. All these processes occur in the mitochondria.

Krebs Cycle

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