what molecule initiates the citric acid cycle by reacting with oxaloacetate course hero

by Prof. Elisa Farrell MD 4 min read

What is the link between the citric acid cycle and oxygen?

The citric acid cycle (CAC) is activated in the presence of oxygen, but what is the link between the CAC and oxygen? A) Oxygen is an allosteric activator for citrate synthase. B) The iron-sulfur center requires oxygen to be in the appropriate oxidation state.

How is OAA synthesized from acetyl CoA?

E) OAA is synthesized via pyruvate carboxylase in an anapleurotic reaction that occurs when acetyl CoA is present. E) OAA is synthesized via pyruvate carboxylase in an anapleurotic reaction that occurs when acetyl CoA is present.

How is OAA formed in the cell cycle?

A) OAA can be formed by the condensation of two moles of acetyl CoA and occurs when the energy charge of the cell is high. B) The rate of the cycle is increased when the cell has high levels of NADH.

What is the product of isocitrate lyase?

B) Isocitrate lyase hydrolyzes isocitrate to form malate and acetate; acetate is used to synthesize glucose. C) One product of isocitrate lyase is succinate, a potent inhibitor of pyruvate kinase.

What molecule initiates the citric acid cycle by reacting with oxaloacetate?

Glycolysis produces pyruvate molecules, , and ATP. The pyruvate molecules undergo reactions that convert the three carbon pyruvate to a two carbon acetyl CoA and an one carbon carbon dioxide. The acetyl-CoA molecules are then used as the initial inputs for the citric acid cycle, as they are combined with oxaloacetate.

Which molecule will combines with oxaloacetate to form citric acid?

Acetyl CoAAcetyl CoA combines with oxaloacetate in a reaction catalyzed by citrate synthase.

How does oxaloacetate regulate the citric acid cycle?

1:1312:53Regulation of Citric Acid Cycle - YouTubeYouTubeStart of suggested clipEnd of suggested clipBut basically by regulating. This step we call pyruvate decarboxylation. By either turning it on orMoreBut basically by regulating. This step we call pyruvate decarboxylation. By either turning it on or off we can regulate. The rate of the citric acid cycle. Now that's the first process of regulation.

What type of reaction is involved in the formation of citrate from oxaloacetate and acetyl-CoA?

Citrate synthase catalyzes the Claisen condensation between acetyl CoA and oxaloacetate to yield, after hydrolysis of the thioester bond, citrate and CoA. This reaction probably occurs via the stabilized enolate anion of acetyl CoA.

What molecule starts the citric acid cycle?

oxaloacetateThe citric acid cycle is called a cycle because the starting molecule, oxaloacetate (which has 4 carbons), is regenerated at the end of the cycle.

What is oxaloacetate made from?

A pyruvate molecule is carboxylated by a pyruvate carboxylase enzyme, activated by a molecule each of ATP and water. This reaction results in the formation of oxaloacetate.

Which amino acids are converted to oxaloacetate?

2 Amino acids catabolized to oxaloacetate. Aspartate and asparagine are both readily catabolized to oxaloacetate.

What amino acids are derived from oxaloacetate?

The oxaloacetate/aspartate family of amino acids is composed of lysine, asparagine, methionine, threonine, and isoleucine. Aspartate can be converted into lysine, asparagine, methionine and threonine. Threonine also gives rise to isoleucine.

What reactants are required for the citric acid cycle?

What Are the Reactants of the Citric Acid Cycle? The Citric Acid Cycle reactants include pyruvic acid, oxaloacetic acid, succinic acid, fumarate and malate. In the first stage, pyruvic acid is oxidized into a molecule called acetyl-coenzyme A.

What activates citrate synthase?

In the citric acid cycle, these remaining carbon atoms are fully oxidized to form carbon dioxide. Citrate synthase starts this process by taking the molecules of acetate and attaching them to oxaloacetate, which acts as a convenient handle as the carbon atoms are passed from enzyme to enzyme in the citric acid cycle.Molecule of the Month: Citrate Synthase - PDB-101https://pdb101.rcsb.org › motmhttps://pdb101.rcsb.org › motmSearch for: What activates citrate synthase?

What enzymes catalyze the conversion of acetyl CoA and oxaloacetate to citrate?

The first step is fusion of the acetyl group of acetyl-CoA with oxaloacetate, catalyzed by citrate synthase. CoA-SH and heat are released and citrate is produced. Citrate is isomerized by dehydration and rehydration to isocitrate. The enzyme aconitase catalyzes these two steps using cis-aconitate as the intermediate.Citric Acid Cycle - an overview | ScienceDirect Topicshttps://www.sciencedirect.com › topics › neuroscience › ci...https://www.sciencedirect.com › topics › neuroscience › ci...Search for: What enzymes catalyze the conversion of acetyl CoA and oxaloacetate to citrate?

When acetyl CoA reacts with oxaloacetate what is produced?

citrateAcetyl CoA to CO In the presence of oxygen, acetyl CoA delivers its acetyl group to a four-carbon molecule, oxaloacetate, to form citrate, a six-carbon molecule with three carboxyl groups.Jun 1, 20227.3B: Acetyl CoA to CO₂ - Biology LibreTextshttps://bio.libretexts.org › 7:_Cellular_Respiration › 7.3:_...https://bio.libretexts.org › 7:_Cellular_Respiration › 7.3:_...Search for: When acetyl CoA reacts with oxaloacetate what is produced?

Which of the following is an input to the citric acid cycle?

Acetyl-CoA is the starting ingredient for the Citric Acid Cycle, which is carried out inside a cell's mitochondria (the famed “powerhouse of the cell”). Carbon dioxide being released, and 2 acetyl-CoA molecules ready to begin the citric acid cycle inside a mitochondrion.

What molecule joins with the pyruvate to form acetyl CoA during the preparatory step?

Coenzyme AA carboxyl group is removed from pyruvate and released as carbon dioxide. The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH. The oxidized two-carbon molecule, an acetyl group, is attached to Coenzyme A to form acetyl CoA.

Which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?

Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see the accompanying figure)? In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle.

What occurs during the citric acid cycle quizlet?

In the cycle a series of reactions oxidize a two-carbon acetyl unit that may be derived from the metabolism of carbohydrate, fat and or protein. The citric acid cycle generates 3 molecules of NADH, 1 molecule of FADH2, and 1 molecule of GTP(ATP) per acetyl-sCoA that enters the cycle.