Krebs Cycle Overview and Functions

<p>32 ATP (C)</p> Signup and view all the answers

<p>Slows down the cycle (A)</p> Signup and view all the answers

<p>Pyruvate Carboxylase reaction (B)</p> Signup and view all the answers

<p>ADP (D)</p> Signup and view all the answers

<p>NADH concentration (D)</p> Signup and view all the answers

<p>It is oxidized to CO2 and H2O. (A)</p> Signup and view all the answers

<p>To oxidize Acetyl-CoA to CO2 and produce ATP. (A)</p> Signup and view all the answers

<p>NADH and FADH2 (B)</p> Signup and view all the answers

<p>Glycolysis is a linear pathway while the TCA cycle is cyclic. (C)</p> Signup and view all the answers

<p>Two molecules of CO2 are released. (B)</p> Signup and view all the answers

<p>NAD+ and FAD (C)</p> Signup and view all the answers

<p>They are used for nucleic acid synthesis. (C)</p> Signup and view all the answers

<p>Energy production is significantly reduced. (C)</p> Signup and view all the answers

Also known as Tricarboxylic Acid (TCA) cycle, it's a central metabolic pathway that occurs in the mitochondria of cells and involves a series of enzyme-catalyzed reactions that oxidize acetyl-CoA to carbon dioxide, producing reducing equivalents (NADH and FADH2) used in oxidative phosphorylation to generate ATP.

The Krebs Cycle requires oxygen. This is because oxygen serves as the final electron acceptor in oxidative phosphorylation, the process that ultimately uses the reducing equivalents produced by the cycle to generate ATP.

When the cell lacks oxygen, the energy production process is less efficient, yielding only around 6% of the energy produced under aerobic conditions. This is because the absence of oxygen prevents the complete oxidation of pyruvate.

During the Krebs Cycle, the enzyme-catalyzed reactions reduce coenzymes NAD+ and FAD to NADH and FADH2, respectively. These reduced coenzymes then carry electrons to oxidative phosphorylation, where they are used to generate ATP.

The Krebs Cycle generates ATP, the main energy currency of the cell, by directly phosphorylating GDP to GTP. The process also produces reducing equivalents (NADH and FADH2) that can be used to generate more ATP through oxidative phosphorylation.

The Krebs Cycle is a key metabolic pathway that serves two primary purposes: 1. It helps oxidize acetyl-CoA to CO2 and produces energy in the form of ATP and reducing equivalents (NADH and FADH2). 2. It provides intermediates that are used for biosynthesis of various biomolecules.

The Krebs Cycle is a cyclic pathway consisting of a series of enzyme-catalyzed reactions that occur in the mitochondrial matrix. It is in contrast to glycolysis, which is a linear pathway that occurs in the cytosol.

The Krebs Cycle requires oxygen, unlike glycolysis, which can occur in the absence of oxygen. The need for oxygen is because the Krebs Cycle relies on oxidative phosphorylation, which uses oxygen as the final electron acceptor to generate ATP.

The Krebs Cycle (also known as the Citric Acid Cycle) is a key metabolic pathway that occurs in the mitochondria of eukaryotic cells and the cytoplasm of prokaryotes. It is a series of chemical reactions that break down acetyl-CoA, derived from carbohydrates, fats, and proteins, into carbon dioxide, generating energy in the form of ATP, NADH, and FADH2.

Each turn of the Krebs Cycle produces 3 molecules of NADH, 1 molecule of FADH2, and 1 molecule of GTP (which can be converted to ATP).

The oxidation of one NADH molecule yields 2.5 ATP molecules, while the oxidation of one FADH2 molecule yields 1.5 ATP molecules.

Complete oxidation of one molecule of acetyl-CoA through the Krebs Cycle and oxidative phosphorylation yields a total of 10 ATP molecules.

The Krebs Cycle is regulated by the energy level of the cell. When the energy level is high, the cycle slows down, and when it is low, the cycle speeds up.

The Krebs Cycle is regulated by small molecule modulators, covalent modification of enzymes, and the supply of acetyl-CoA.

Citrate synthase, isocitrate dehydrogenase, and α-ketoglutarate dehydrogenase are key enzymes in the Krebs Cycle, and their activity is regulated by various factors, including the levels of NADH, ATP, ADP, and other metabolites.

Anaplerotic reactions are metabolic pathways that replenish the intermediates of the Krebs Cycle. These reactions are essential for maintaining the cycle's function.