short note on Krebs Krebs cycle
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Most organisms use glucose as a major fuel source, but must break down this glucose and store the energy in ATP and other molecules. The Krebs cycle is contained within mitochondria. Within the mitochondrial matrix, the reactions of the Krebs cycle adds electrons and protons to a number of electron carriers, which are then used by the electron transport chain to produce ATP.
The Krebs cycle starts with the products of glycolysis, which are two three-carbon molecules known as pyruvate. This molecule is acidic, which is why the Krebs cycle is also called the tricarboxylic acid cycle (TCA). Throughout a number of reactions, these molecules are further broken down into carbon dioxide. Energy from the molecules is moved to other molecules, called electron carriers. These molecules carry the stored energy to the electron transport chain, which in turn creates ATP.
Then, the cell uses this ATP to power various cellular reactions, such as the activation of enzymes or transport proteins. The Krebs cycle is the second of 4 different processes which must happen to extract the energy from glucose. Altogether, the Krebs cycle consists of 9 sequential reactions.
The Krebs Cycle, also called the Citric acid cycle, is the second major step in oxidative phosphorylation. After glycolysis breaks glucose into smaller 3-carbon molecules, the Krebs cycle transfers the energy from these molecules to electron carriers, which will be used in the electron transport chain to produce ATP.
Krebs Cycle Overview :
Most organisms use glucose as a major fuel source, but must break down this glucose and store the energy in ATP and other molecules. The Krebs cycle is contained within mitochondria. Within the mitochondrial matrix, the reactions of the Krebs cycle adds electrons and protons to a number of electron carriers, which are then used by the electron transport chain to produce ATP.
The Krebs cycle starts with the products of glycolysis, which are two three-carbon molecules known as pyruvate. This molecule is acidic, which is why the Krebs cycle is also called the tricarboxylic acid cycle (TCA). Throughout a number of reactions, these molecules are further broken down into carbon dioxide. Energy from the molecules is moved to other molecules, called electron carriers. These molecules carry the stored energy to the electron transport chain, which in turn creates ATP.
Then, the cell uses this ATP to power various cellular reactions, such as the activation of enzymes or transport proteins. The Krebs cycle is the second of 4 different processes which must happen to extract the energy from glucose. Altogether, the Krebs cycle consists of 9 sequential reactions.
Where Does the Krebs Cycle Take Place?
The Krebs cycle happens only within the mitochondrial matrix. Pyruvate is formed in the cytosol of the cell, then imported into the mitochondria. Here, it is converted to acetyl CoA and imported into the mitochondrial matrix. The mitochondrial matrix is the innermost part of the mitochondria. The graphic below shows the different parts of mitochondria.
The mitochondrial matrix has the required enzymes and environment for the complex reactions of the Krebs cycle to take place. Further, the products of the Krebs cycle drive the electron transport chain and oxidative phosphorylation, both of which occur in the inner mitochondrial membrane. The electron carriers will dump their electrons and protons into the chain, which ultimately drives the production of ATP. This molecule is then exported from the mitochondria as the main energy source for the cell.
Mitochondria are found in almost all organisms, especially multicellular organisms. Plants, animals, and fungi all use the Krebs cycle as an indispensable part of aerobic respiration.