Table of Contents
What is TCA Cycle?
TCA Cycle – Introduction: The tricarboxylic acid cycle (TCA cycle), also known as the citric acid cycle or the Krebs cycle, is a series of enzyme-catalyzed chemical reactions that occur in the mitochondria of cells. The TCA cycle is used to generate energy in the form of adenosine triphosphate (ATP), as well as to produce certain cellular metabolites.
- The TCA cycle begins with the oxidation of pyruvate, a molecule produced by the breakdown of carbohydrates. This oxidation is catalyzed by the enzyme pyruvate dehydrogenase. The pyruvate molecule is converted into acetyl-CoA, which is then oxidized by the enzyme aconitase. The products of this oxidation are carbon dioxide and water. The carbon dioxide is released into the bloodstream, while the water is transported to the cells’ organelles, the mitochondria.
- In the mitochondria, the acetyl-CoA is converted into citrate by the enzyme citrate synthase. The citrate is then cleaved by the enzyme citrate lyase, resulting in the production of oxaloacetate. The oxaloacetate is then converted into malate by the enzyme malate dehydrogenase. The malate is then transported back to the mitochondria, where it is converted into oxaloacetate by the enzyme malate dehydrogenase. This process is repeated until the oxaloacetate is used up.
- The final step of the TCA cycle is the conversion of oxaloacetate into citrate by the enzyme citrate synthase. The citrate is then transported out of the mitochondria and into the cytosol, where it is used to produce ATP.
Why is The TCA Cycle Also Called The Krebs Cycle?
- The TCA cycle is also called the Krebs cycle because it was first described by Hans Krebs.
- The TCA cycle is also called the Krebs cycle because it was first discovered and described by Hans Krebs. The TCA cycle is a series of biochemical reactions that produce energy in the form of adenosine triphosphate (ATP) from food molecules. The Krebs cycle is the second step in the process of aerobic respiration, in which the energy in food molecules is converted into ATP. The first step is glycolysis, in which glucose is converted into two molecules of pyruvate. The pyruvate molecules are then transported into the mitochondria, where the Krebs cycle takes place. The Krebs cycle is a series of eight reactions that convert the pyruvate molecules into carbon dioxide and water, and release energy that is used to produce ATP.
Steps of TCA Cycle
The steps of the TCA cycle are:
- Pyruvate is converted to acetyl coenzyme A (acetyl-CoA) by the enzyme pyruvate dehydrogenase.
- Acetyl-CoA is converted to citrate by the enzyme citrate synthase.
- Citrate is converted to isocitrate by the enzyme isocitrate dehydrogenase.
- Isocitrate is converted to α-ketoglutarate by the enzyme α-ketoglutarate dehydrogenase.
- α-ketoglutarate is converted to succinyl-CoA by the enzyme α-ketoglutarate dehydrogenase.
- Succinyl-CoA is converted to succinate by the enzyme succinate dehydrogenase.
- Succinate is converted to fumarate by the enzyme succinate dehydrogenase.
- Fumarate is converted to malate by the enzyme fumarase.
- Malate is converted to oxaloacetate by the enzyme malate dehydrogenase.
- Oxaloacetate is converted to pyruvate by the enzyme pyruvate carboxylase.
The tricarboxylic acid (TCA) cycle, also known as the citric acid cycle, is a series of enzymatic reactions that occur in the cytoplasm of all eukaryotic cells. The cycle is responsible for the production of adenosine triphosphate (ATP), the energy currency of the cell. The cycle begins with the oxidation of acetyl coenzyme A (acetyl-CoA) to carbon dioxide and water. This reaction is catalyzed by the enzyme acetyl-CoA synthetase. Acetyl-CoA is then transported into the mitochondrial matrix, where it is converted to citrate by the enzyme citrate synthase. The citrate is then converted to isocitrate by the enzyme isocitrate dehydrogenase. Isocitrate is then converted to alpha-ketoglutarate by the enzyme alpha-ketoglutarate dehydrogenase. Alpha-ketoglutarate is then converted to succinyl-CoA by the enzyme succinyl-CoA synthetase. Succinyl-CoA is then converted to succinate by the enzyme succinate dehydrogenase. Succinate is then converted to fumarate by the enzyme fumarate reductase. Fumarate is then converted to malate by the enzyme fumarase. Malate is then converted to oxaloacetate by the enzyme malate dehydrogenase. Finally, oxaloacetate is converted to citrate by the enzyme citrate synthase. The cycle is then repeated.
The steps of the TCA cycle are as follows:
1. Oxidation of acetyl-CoA to carbon dioxide and water.
2. Transport of acetyl-CoA into the mitochondrial matrix.
3. Conversion of acetyl-CoA to citrate by the enzyme citrate synthase.
4. Conversion of citrate to isocitrate by the enzyme isocitrate dehydrogenase.
5. Conversion of isocitrate to alpha-ketoglutarate by the enzyme alpha-ketoglutarate dehydrogenase.
6. Conversion of alpha-ketoglutarate to succinyl-CoA by the enzyme succinyl-CoA synthetase.
7. Conversion of succinyl-CoA to succinate by the enzyme succinate dehydrogenase.
8. Conversion of succ
End Products of TCA Cycle
The final products of the TCA cycle are:
- 2 carbon molecules
- 4 hydrogen molecules
- 1 ATP molecule
- 1 NADH molecule
The end products of the TCA cycle are acetyl-CoA, oxaloacetate, and carbon dioxide. Acetyl-CoA is produced when one molecule of glucose is converted to two molecules of acetyl-CoA. This occurs during glycolysis, the first step of the glycolysis pathway. Oxaloacetate is produced when the four-carbon molecule, malate, is converted to the two-carbon molecule, oxaloacetate. Malate is produced when the two-carbon molecule, pyruvate, is converted to the four-carbon molecule, malate. Pyruvate is produced when the one-carbon molecule, acetate, is converted to the two-carbon molecule, pyruvate. Carbon dioxide is produced when the two-carbon molecule, carbon dioxide, is converted to the one-carbon molecule, carbon dioxide.
To Sum Up The Entire Cycle
Overall, the menstrual cycle is a process that prepares the body for possible pregnancy. It involves the release of hormones that control the ovaries and the uterus. The cycle begins with the release of an egg from an ovary and ends with the onset of menstruation.
The tricarboxylic acid (TCA) cycle is a series of biochemical reactions that produce energy in the form of adenosine triphosphate (ATP) from simple molecules like glucose. The cycle begins with the oxidation of glucose to two molecules of pyruvate. Pyruvate is then oxidized to acetyl coenzyme A (acetyl-CoA), which enters the TCA cycle. The cycle consists of five steps:
1. Oxidation of acetyl-CoA to carbon dioxide and water.
2. Conversion of the carbon dioxide to carbon monoxide and hydrogen.
3. Reduction of the carbon monoxide to methane and water.
4. Oxidation of the methane to methanol and water.
5. Conversion of the methanol to formaldehyde and water.
The TCA cycle is also called the Krebs cycle, after the German scientist who discovered it in the 1930s.
