EVERYDAY SCIENCE

Detailed explanation-1: -The Krebs cycle itself actually begins when acetyl-CoA combines with a four-carbon molecule called OAA (oxaloacetate) (see Figure above). This produces citric acid, which has six carbonatoms. This is why the Krebs cycle is also called the citric acid cycle.

Detailed explanation-2: -At the end of this series of reactions, the four-carbon starting molecule, oxaloacetate, is regenerated, allowing the cycle to begin again.

Detailed explanation-3: -In the citric acid cycle, oxaloacetate (a 4 carbon molecule) is combined with acetyl CoA (a 2 carbon molecule) to generate the 6 carbon molecule citric acid.

Detailed explanation-4: -Answer and Explanation: Oxaloacetate is one of the essential intermediates of the Krebs cycle. It results in the formation of the citrate after reacting with acetyl-CoA. Citrate synthase plays a significant role in catalyzing carrying out this reaction.

Detailed explanation-5: -Acetyl CoA is a two-carbon compound that enters the TCA cycle. It combines with a four-carbon compound called oxaloacetate to produce a six-carbon molecule called citrate and releases the CoA group. This oxaloacetate molecule will be regenerated at the end of the cycle from malate.