In glycolysis, ATP molecules are produced by _____.

In glycolysis, ATP molecules are produced by _. Here is the answer and explanation of the What, in glycolysis, ATP molecules are produced by?

This biology question belonged to the MCAT practice test.

In glycolysis, ATP molecules are produced by _.

In glycolysis, what ATP molecules are produced by?

• Photosynthesis
• Cellular respiration
• Photophosphorylation
• Substrate-level phosphorylation
• Oxidative phosphorylation

Below is the correct answer and explanation.

Glycolysis

Glycolysis is a 10-step enzyme-catalyzed process that begins with the breakdown of glucose into pyruvate.

The primary physiological function of sugars is to provide the body with energy for life activities. Sugar catabolism is the main way in which organisms obtain energy.

There are three main pathways for the oxidative breakdown of sugars in living organisms.

• Anaerobic oxidation of sugar
• Aerobic oxidation of sugar
• pentose phosphate

A series of enzymes catalyzing the glycolytic reactions are present in the cytoplasm, so all the reactions of glycolysis are carried out in the cytoplasm. Glycolysis is a common stage through which all organisms must undergo glucose catabolism.

Under normal physiological conditions, various metabolic processes in the body are strictly and finely regulated to maintain the stability of the internal environment and to meet the needs of the physiological activities of the organism. This regulatory control is achieved mainly by changing the activity of enzymes.

Hexokinase, phosphofructokinase-1 and pyruvate kinase are the key enzymes of glycolysis, and their activities directly affect the speed and direction of the whole metabolic pathway, among which phosphofructokinase-1 is the most important.

Reaction characteristics

• The whole process of glycolysis reaction is without the participation of oxygen.
• Less energy is released in the glycolytic reaction. Sugar is metabolized in an enzymatic manner and only incomplete oxidation can occur.
• There are 3 rate-limiting enzymes in the whole process of glycolysis reaction. In the whole process of glycolysis reaction. The three steps are irreversible reactions. These three steps are catalyzed by 3 rate-limiting enzymes, hexokinase, 6-phosphofructokinase-1, and pyruvate kinase, respectively.

ATP molecules

Purine nucleoside triphosphate (abbreviated as adenosine triphosphate), chemical formula C10H16N5O13P3, molecular weight 507.18, is unstable, high-energy chemistry. It consists of 1 molecule of adenine, 1 molecule of ribose, and 3 molecules of the phosphate group. It is also known as adenosine triphosphate (ATP).

ATP is made up of adenine, ribose and 3 phosphate groups linked together. It releases more energy upon hydrolysis and is the most direct source of energy in living organisms.

ATP is a high-energy phosphate compound. In cells, it can store and release energy by interconversion with ADP, thus ensuring the energy supply for all cellular life activities.

There are two main pathways for the production of ATP.

• One is the production of ATP by cells containing chloroplasts in plants during the light reaction phase of photosynthesis.
• The other is that all living cells can produce ATP through cellular respiration.

Muscle stores a variety of energy substances, mainly adenosine triphosphate (ATP), creatine phosphate (CP), myoglycogen and fat.

ATP is a constant source of energy as it is easily regenerated in the cells. This process of using the energy released from exergonic reactions for energy-absorbing reactions through the hydrolysis and synthesis of ATP is called the ATP cycle.

Because ATP is a commonly used carrier of energy in cells, it is often referred to as the energy currency of the cell.

The energy supply mechanism of interconversion of ATP and ADP in cells is common to the biological world. From the bioenergetics point of view, ATP is the core of biochemical systems.

Substrate-level phosphorylation

In glycolysis, ATP molecules are produced by what process?

Substrate-level phosphorylation is the process of biological oxidation of substances, often generating some compounds containing high-energy bonds. And these compounds can be directly coupled to the synthesis of ATP or GTP.

Substrate-level phosphorylation refers to the redistribution of energy within the molecule as a result of dehydrogenation and dehydration of the substrate during catabolism, resulting in the formation of high-energy phosphate compounds. The high-energy phosphate group is then transferred to ADP to form ATP.

For example, during the catabolism of sugar, glyceraldehyde-3-phosphate is dehydrogenated and phosphorylated to form glyceraldehyde-1,3-bisphosphate. A high-energy phosphate group is formed in the molecule, and under enzyme catalysis, glyceraldehyde-1,3-bisphosphate can transfer the high-energy phosphate group to ADP to produce glyceraldehyde-3-phosphate with ATP.

Another example is that when glyceric acid-2-phosphate is dehydrated to generate enol pyruvate phosphate, it can also form a high-energy phosphate group inside the molecule, which can then be transferred to ADP to generate ATP.

Photosynthesis

Photosynthesis is the process by which green plants absorb light energy and synthesize carbon dioxide and water into the energy-rich organic matter while releasing oxygen.

Photosynthesis consists of two main stages: the light reaction and the dark reaction. The process of photosynthesis involves light absorption, electron transfer, photosynthetic phosphorylation, carbon assimilation, and other important reaction steps. It is important to realize the energy conversion in nature and maintain the carbon-oxygen balance in the atmosphere.

Correct Answer

• Answer: D. Substrate-level phosphorylation

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