To enter the citric acid cycle, pyruvate must enter the mitochondria by active transport. three things are necessary to convert pyruvate to acetyl coa. explain the three steps in the conversion process.

Decarboxylation, the Reduction of NAD+, and the attachment of CoA.

Explanation:

Step 1 Decarboxylation: the co-enzyme thiamine pyrophosphate (TPP) catalyzes the decarboxylation of the carboxyl group of pyruvate and given off as a molecule of CO2. The two carbon unit remains attached to the enzyme.

Step 2 Reduction: The remaining two-carbon (hydroxyethyl group) is oxidized to form acetyl group. The extracted electrons are transferred to NAD+, storing energy in the form of NADH.

Step 3. The last step is the attachment of coenzyme A, a sulfur compound derived from a B vitamin, is attached to the acetyl group to form acetyl CoA, the Co-enzymes TPP, Lipoamide and FAD will be regenerated.

The acetyl CoA will go into TCA for complete oxidation.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]