This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category 'Other. The cookies is used to store the user consent for the cookies in the category 'Necessary'. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category 'Functional'. The cookie is used to store the user consent for the cookies in the category 'Analytics'. These cookies ensure basic functionalities and security features of the website, anonymously.

Necessary cookies are absolutely essential for the website to function properly. Calcium: Accelerates the TCA cycle by stimulating the link reaction.This reduces the rate of production of pyruvate and therefore of acetyl-coA. Citrate: Inhibits phosphofructokinase, a key enzyme in glycolysis.For example, NADH inhibits the majority of the enzymes found in the TCA cycle. Metabolites: Products of the cycle provide negative feedback on the enzymes that catalyse it.The TCA Cycle is regulated in a variety of ways:

Therefore, each molecule of glucose produces double the net output of each cycle. Net OutputĮach molecule of glucose produces two molecules of pyruvate, which in turn produce two molecules of acetyl-coA. For example, alpha-ketoglutarate can leave the cycle to be converted into amino acids, and succinate can be converted to haem. These enter or exit the cycle at various points depending on demand. While the primary role of the TCA cycle is production of NADH and FADH₂, it also produces molecules that supply various biosynthetic processes. Fig 1 - Diagram showing the steps of the TCA cycle. Acetyl-coA is the intermediate that enters the TCA cycle. Pyruvate is then decarboxylated to form acetyl-coA by the pyruvate decarboxylase complex. Prior to the TCA cycle, glycolysis has occurred, which generates molecules including pyruvate, ATP and NADH. In this article we will outline the steps and regulation of this essential part of cellular physiology. These electrons come from electron carriers such as NADH and FADH₂, which are produced by the Tricarboxylic Acid Cycle (TCA cycle, also known as the Kreb's/Citric Acid cycle). In order for ATP to be produced through oxidative phosphorylation, electrons are required for ATP to pass down the electron transport chain. The third molecule of NADH is also produced. Step 8: Malate is then converted into oxaloacetate.Step 7: Fumarate is converted to malate (another 4 carbon molecule).Step 6: Succinate is converted into fumarate (4 carbon molecule) and a molecule of FADH₂ is produced.Step 5: Succinyl CoA is then converted to succinate (4 carbon molecule) and one GTP molecule is produced.A second molecule of NADH is produced, alongside a second molecule of carbon dioxide. This binds to coenzyme A, forming succinyl CoA. Step 4: Alpha-ketoglutarate is oxidised to form a 4 carbon molecule.This is a rate limiting step, as isocitrate dehydrogenase is an allosterically controlled enzyme. The enzyme responsible for catalysing this step is isocitrate dehydrogenase. Step 3: Isocitrate is oxidised to alpha-ketoglutarate (a five carbon molecule) which results in the release of carbon dioxide.Step 2: Citrate is converted to isocitrate (an isomer of citrate).Step 1: Acetyl CoA (two carbon molecule) joins with oxaloacetate (4 carbon molecule) to form citrate (6 carbon molecule).It takes place over eight different steps: The TCA cycle is a central pathway that provides a unifying point for many metabolites, which feed into it at various points.

Summarize the steps of the water cycle.