Aerobic Respiration Part 2 (Pyruvate oxidation)

Summary

In this video, Seher explains pyruvate oxidation, the second step of aerobic respiration that follows glycolysis. Two pyruvate molecules enter the mitochondria, where they release carbon dioxide and are converted into acetyl-CoA by the enzyme pyruvate dehydrogenase. This process also produces NADH, an important energy carrier. The acetyl-CoA then enters the Krebs cycle, leading to the release of more carbon dioxide and the generation of energy in the form of ATP. The video effectively outlines the transformation of glucose into energy, highlighting the significance of each step in cellular respiration.

Takeaways

• 😀 Pyruvate oxidation is the second step of aerobic respiration, following glycolysis.
• 😀 Glycolysis converts glucose (a six-carbon compound) into two pyruvate molecules (three-carbon compounds).
• 😀 Pyruvate enters the mitochondria with the help of transport proteins.
• 😀 Each pyruvate molecule releases one carbon dioxide (CO₂) as it undergoes conversion to acetyl-CoA.
• 😀 The enzyme pyruvate dehydrogenase catalyzes the conversion of pyruvate to acetyl-CoA.
• 😀 Pyruvate dehydrogenase removes hydrogen from coenzyme A, which then forms NADH from NAD⁺.
• 😀 Acetyl-CoA, a two-carbon compound, is prepared to enter the Krebs cycle (citric acid cycle).
• 😀 In the Krebs cycle, additional CO₂ is released, contributing to the total of six CO₂ from one glucose molecule.
• 😀 The remaining energy from this process is stored in NADH and FADH₂, which will enter the electron transport chain.
• 😀 Oxygen serves as the final electron acceptor in the electron transport chain, forming water.

Q & A

What is pyruvate oxidation?

Pyruvate oxidation is the second step of aerobic respiration, where pyruvate is converted into acetyl-CoA.

What is the first step of aerobic respiration before pyruvate oxidation?

The first step is glycolysis, in which glucose is converted into two molecules of pyruvate.

How many molecules of pyruvate are produced from one molecule of glucose?

One molecule of glucose is converted into two molecules of pyruvate.

Where does pyruvate oxidation occur in the cell?

Pyruvate oxidation occurs in the mitochondria of the cell.

What happens to pyruvate when it enters the mitochondria?

Upon entering the mitochondria, pyruvate releases carbon dioxide and is converted into acetyl-CoA.

What enzyme is responsible for converting pyruvate to acetyl-CoA?

The enzyme responsible for this conversion is pyruvate dehydrogenase.

What does the enzyme pyruvate dehydrogenase do?

Pyruvate dehydrogenase removes hydrogen from pyruvate, which is then transferred to NAD+ to form NADH.

What is the significance of acetyl-CoA in cellular respiration?

Acetyl-CoA is a crucial molecule that enters the Krebs cycle (citric acid cycle) for further energy extraction.

How many carbon dioxide molecules are produced from one molecule of glucose during aerobic respiration?

A total of six carbon dioxide molecules are produced from one molecule of glucose during aerobic respiration.

What happens to the energy released during aerobic respiration?

The energy is captured in the form of NADH and FADH2, which then enter the electron transport chain to produce ATP.