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The Krebs Cycle: The Best explanation – Functions & Products

The Krebs Cycle is also known as the Citric Acid Cycle and Tricarboxylic Acid Cycle, this is an important biochemical process that happens within the mitochondria (Powerhouse of the Cell) of eukaryotic cells.

Another thing rises to mind who discovered was the Krebs Cycle, so Sir Hans Krebs found it and was named after its founder, he found that the cycle is an essential part of cellular respiration, and this is responsible for producing energy with the help of breaking carbohydrates, fats, and proteins.

In this article, we will also know about the function of the Krebs Cycle, where the Krebs Cycle happens, and what are the products of the Krebs Cycle, and we will also explore its significance in our cellular metabolism.

The Krebs Cycle

What is the Krebs Cycle and its Function?

The Krebs cycle is an important process of our cellular metabolism that plays an important role in obtaining energy from food. It is the second stage of cellular respiration after Glycolysis, and it is required for the complete oxidation of acetyl-CoA molecules derived from carbohydrates, fats, and proteins.

The main function of the Krebs cycle is to produce energy in the form of ATP (Adenosine Triphosphate) and to produce the power and energy NADH and FADH2 used in energy production. The electricity of Mitochondria continues to produce more ATP.

The Krebs Cycle

Where does the Krebs Cycle Occurs?

If you want to know that where The Krebs cycle happens in the mitochondrial matrix of eukaryotic cells. Mitochondria are known as the “powerhouses of the cell” because of their role in energy production. The Krebs cycle enzymes and substrates exist in the mitochondrial matrix to allow the cycle to function properly.

The Krebs Cycle

The Krebs Cycle Diagram:

Here is a simplified diagram of the Krebs Cycle

The Krebs Cycle

The Krebs cycle starts when acetyl-CoA combines with 4-carbon molecules, and it is called oxaloacetate to form a 6-carbon molecule called citrate. Through the chemical reaction, citrate undergoes many changes that lead to the regeneration of oxaloacetate at the end of the cycle.
Intermediates in this process produce energy molecules such as NADH and FADH2, which transport energy down the energy transport chain to produce ATP.

The Krebs Cycle

The Krebs Cycle Products:

The Krebs Cycle yields several important products:

ATP: Adenosine triphosphate is a large energy molecule. This is a source of energy for cells. During the Krebs cycle, ATP is produced directly by substrate-level phosphorylation and indirectly by the electron transport chain.

NADH and FADH2: These are also energy sources for high-energy cells produced during storage.

The Krebs Cycle

The Steps of the Krebs Cycle:

The Krebs cycle includes 8 enzymatic reactions, each of which is performed by a particular enzyme.

Here is a brief description of the steps involved:

Step 1: Acetyl-CoA (2-carbons) combines with oxaloacetate (4-carbons) to form citrate (6-carbons).
Step 2: The citrate is isomerized to form its isomer isocitrate.
Step 3: Oxidative decarboxylation of isocitrate to form α-ketoglutarate releases a molecule of CO2 and produces NADH.
Step 4:

α-ketoglutarate undergoes another oxidative decarboxylation to form succinyl-CoA, releasing another CO2 molecule and producing NADH.
Step 5: Succinyl-CoA is reformed to succinate and phosphorylated at the substrate level to produce an ATP molecule.
Step 6: Succinic acid is oxidized to fumaric acid and makes FADH2.
Step 7: Fumaric acid is hydrated to form malic acid.
Step 8: Lastly Malic acid is oxidized to form oxaloacetate to form NADH.

The Krebs Cycle


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Final Verdict:

The Krebs cycle is an important metabolic process that enables cells to efficiently convert nutrients and produces ATP, which is needed for many cellular processes.
The Krebs Cycle happens in the mitochondria and performs several chemical reactions which produce energy-rich products such as ATP, NADH, and FADH2.

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