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How does the pyruvate produced by glycolysis enter the mitochondrion?
Wiki User
∙ 10y ago
Pyruvate enters the Krebs cycle via an intermediate called acetyl CoA.
Pyruvate is formed in the cytoplasm as the end product of glycolysis. Pyruvate enters a mitochondrion, in the matrix of which it encounters the enzyme pyruvate dehydrogenase. This enzyme catalyzes the reaction of pyruvate with coenzyme A to form acetyl CoA. This reaction is sometimes called the link reaction, as it links glycolysis to the Krebs cycle (= citric acid cycle, or tricarboxylic acid cycle).
"Pyruvate dehydrogenase" is in fact a huge complex (bigger than a ribosome) consisting of three enzymes and a number of other substances, including coenzymes. In the course of the reaction NAD+ is reduced to NADH. A molecule of CO2 is also produced. So this reaction involves a both an oxidation and a decarboxylation.
Acetyl CoA then reacts with oxaloacetate to form citrate. Both oxaloacetate and citrate are intermediates of the Krebs cycle.
Wiki User
∙ 15y ago
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When does Calvin cycle begin?
When acetyl CoA and oxaloacetate is present.
What are two reactants that enter the mitochondrion?
Glucose and Oxygen
Describe the pathway of electrons from the time they enter the intermembrane space of the mitochondrion to the time they are returned to the inside of the mitochondrion?
The electrons move
Is fermentation as effective as glycolysis?
because from glycolisis comes pyruvate, and then it is turned into acetylCoA. Without acetylCoA, nothgn will be able to enter the Krebs Cycle, otherwise known as the Citric acid cycle. Once the AcetylCoA comes in, after the prep cycle, it can then bind to RuBp, turnign into a six carbon sugar.
What has to be present for Pyruvate to enter the mitochondria?
The mitochondrial membrane has special transporter proteins which are needed to transport pyruvate. This transport also requires ATP.
When does Calvin cycle begin?
When acetyl CoA and oxaloacetate is present.
What happens to pyruvate molecules formed glycolysis in the absence of oxygen?
they will enter the Krebs cycle
Why only glucose enters into glycolysis why not other sugars directly enter into glycolysis?
Other sugars do enter into glycolysis such as fructose, galactose and mannose. Fructose can directly enter into glycolysis while the other two is converted to a glucose intermediate molecule because it can produce the two triose phophate molecules (DHAP and G3P) which are needed to generate energy from the reactions (ATP) and pyruvate.
What is a product of aerobic respiration that will enter into and begin the Krebs cycle?
glycolysis yiels 2 pyruvate molecules that will undergo Kreb's cycle
How do redox environment of cell determine weither glycolysis is aerbic or anerobic?
Merely the presence of oxygen determines whether pyruvate will enter the citric acid cycle or be cycled in glycolysis to produce ATP.
How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?
In substrate level phosphorylation, the ADP is phosphorylated directly by the transfer of phosphate group from substrate. If we consider glucose, then we get four substrate level phosphorylated ATPs, net gain of two in glycolysis and other two are formed when the two pyruvate molecules formed after glycolysis enter the TCA cycle.
What is the fate of pyruvate in mitochondrial respiration?
Pyruvate is formed from glucose during glycolysis. Should the conditions be aerobic, pyruvate will be converted into Acetyl Coenzyme A (CoA) with the help of an enzyme called "pyruvate dehydrogenase." Bi-products of this reaction include CO2 and NADH This occurs in the matrix of the mitochondria. Acetyl CoA will then continue into the Krebs cycle/citric acid cycle. After this, the products of the cycle (NADH and FADH2) will be involved in oxidative phosphorylation and the electron transport chain where large amounts of ATP will be produced. This occurs in the inner layer of the mitochondria. Should there be anaerobic conditions, then animals can convert pyruvate into lactate. Or, in plants; pyruvate is converted into ethanal and then into ethanol in a process called fermentation.
Can pyruvic acid use in the Krebs cycle?
The pyruvic acid that is produced by glycolysis is used as the initial input for the Krebs Cycle (also called citric acid cycle). In the initial step of the Krebs Cycle, the pyruvic acid is converted to acetyl-CoA via pyruvate decarboxylation. This continues a series of chemical reactions leading to the production of 2 ATP molecules.
What are two reactants that enter the mitochondrion?
Glucose and Oxygen
Describe the pathway of electrons from the time they enter the intermembrane space of the mitochondrion to the time they are returned to the inside of the mitochondrion?
The electrons move
What can you do with the end product of glycolysis?
The end products of glycolysis enter the Kreb's Cycle or Citric Acid Cycle.
Is fermentation as effective as glycolysis?
because from glycolisis comes pyruvate, and then it is turned into acetylCoA. Without acetylCoA, nothgn will be able to enter the Krebs Cycle, otherwise known as the Citric acid cycle. Once the AcetylCoA comes in, after the prep cycle, it can then bind to RuBp, turnign into a six carbon sugar.
