In the Citric Acid Cycle, ATP Molecules are Produced by _____.？

This is the answer and explanation to In the citric acid cycle, ATP molecules are produced by _.

It belonged to the MCAT Biology practice test.

In the citric acid cycle, ATP molecules are produced by _.

In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _.

1. photophosphorylation
2. substrate-level phosphorylation
3. cellular respiration
4. photosynthesis
5. oxidative phosphorylation

The answer and explanation of What are ATP molecules produced by in the citric acid cycle is below.

What is the citric acid cycle?

The tricarboxylic acid cycle (TCA cycle) is a common metabolic pathway in aerobic organisms. It is distributed in the cytoplasm in prokaryotes and in the mitochondria in eukaryotes.

Because several of the major intermediate metabolites in this cycle are organic acids containing three carboxyl groups. For example, citric acid (C6). This is called the tricarboxylic acid cycle, also known as the citric acid cycle or the TCA cycle.

The complete oxidation of sugars such as glucose under aerobic conditions to produce carbon dioxide and water and to release energy is called aerobic oxidation of sugars. It has been found that muscle chyme does not produce lactate and does not accumulate pyruvate in the presence of oxygen, but energy is still released, why?

The famous biochemist H. Kreb and others made a lot of research work to clarify the metabolism of pyruvate in the presence of oxygen, and proposed the aerobic oxidation pathway of sugar, for which he was awarded the Nobel Prize in 1953.

Under aerobic conditions, the product of myogenic glycolysis, lactate, may also be converted to pyruvate. For example, blood lactate can be used as an energy source by tissues such as the heart muscle and is a reaction performed by the body during the recovery period after intense exercise. During this recovery time, respiration is still accelerated and deepened, and lactate is reoxidized to pyruvate, which is then further oxidized to water and CO2.

Physiological significance of the Citric acid cycle

The complete oxidation of glucose to H2O and CO2 per mole results in a net production of 30 mol or 32 mol ATP.

Therefore, under general physiological conditions, all kinds of tissue cells (except erythrocytes) obtain energy from the aerobic oxidation of sugar.

The aerobic oxidation of sugar is not only efficient but also releases energy gradually and stores it in the ATP molecules. Therefore, the utilization of energy is also extremely high.

Acetyl CoA is not only the product of sugar oxidation and decomposition, but also the product of fatty acid and amino acid metabolism.

Therefore, the tricarboxylic acid cycle is actually the common main pathway for the oxidation and energy supply of the three major organic substances in the body. It is estimated that 2/3 of organic substances in human body are decomposed through the tricarboxylic acid cycle.

The α-ketoglutarate, pyruvate and oxaloacetate produced during the aerobic oxidation of sugar can be transformed into the corresponding amino acids by combining with ammonia. These amino acids, in turn, can be converted to keto acids by removing their amino acids and enter the aerobic oxidation pathway of sugar.

At the same time, glycerol from lipid catabolism and acetyl CoA from fatty acid metabolism can also enter the aerobic oxidation pathway of sugar for metabolism

• Q: In glycolysis, ATP molecules are produced by _____.

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Here is the correct answer to In the citric acid cycle, ATP molecules are produced by _.

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