What happens in malate-aspartate shuttle?

The malate-aspartate shuttle system, also called the malate shuttle, is an essential system used by mitochondria, that allows electrons to move across the impermeable membrane between the cytosol and the mitochondrial matrix. The electrons are created during glycolysis, and are needed for oxidative phosphorylation.

Which enzyme is important for driving the malate-aspartate shuttle?

Mechanism. The primary enzyme in the malate-aspartate shuttle is malate dehydrogenase.

How many enzymes mediate the malate-aspartate shuttle system?

four enzymes
In the heart and liver, electrons from cytosolic NADH are brought into mitochondria by the malate-aspartate shuttle, which is mediated by two membrane carriers and four enzymes (Figure 18.38).

Can malate across the mitochondrial membrane?

On the cytoplasmic side a transaminase enzyme is used to remove an amino group from aspartate which is converted into oxaloacetate, then malate dehydrogenase enzyme uses an NADH cofactor to reduce oxaloacetate to malate which can be transported across the membrane because of the presence of a transporter.

What is the importance of malate-aspartate shuttle?

The malate-aspartate (M-A) shuttle provides an important mechanism to regulate glycolysis and lactate metabolism in the heart by transferring reducing equivalents from cytosol into mitochondria.

Is the malate-aspartate shuttle reversible?

This shuttle is reversible, so electrons from NADH are brought into the mitochondrion when the NADH/NAD+ ratio is higher in the cytosol than in the mitochondrial matrix. The malate-aspartate shuttle yields approximately 3 molecules of ATP per molecule of cytosolic NADH and is found in liver, heart and kidney [Voet04].

Why is the malate-aspartate shuttle Important?

Why do we need malate-aspartate shuttle?

Why is the malate-aspartate shuttle necessary?

How is malate-aspartate shuttle different from the glyceraldehyde 3 phosphate dehydrogenase shuttle?

Glycerol-3-phosphate shuttle generates 2 ATP for every cytosolic molecule oxidized, as FADH2 bypasses the first phosphorylation site in the electron transport chain. Malate aspartate shuttle generates 3 ATP for every cytosolic molecule oxidized. So, it is more efficient than the glycerol-3-phosphate shuttle.

Where does malate-aspartate shuttle occur?

The malate-aspartate shuttle yields approximately 3 molecules of ATP per molecule of cytosolic NADH and is found in liver, heart and kidney [Voet04]. It is quantatively the most important shuttle for the reoxidation of cytosolic NADH in vertebrate tissues under aerobic conditions.

Which of the following processes generates the most ATP?

electron transport chain
Explanation: The electron transport chain generates the most ATP out of all three major phases of cellular respiration. Glycolysis produces a net of 2 ATP per molecule of glucose.

Which is the primary enzyme in the malate aspartate shuttle?

The primary enzyme in the malate-aspartate shuttle is malate dehydrogenase. Malate dehydrogenase is present in two forms in the shuttle system: mitochondrial malate dehydrogenase and cytosolic malate dehydrogenase.

How is malate converted into oxaloacetate and aspartate?

After malate reaches the mitochondrial matrix, it is converted by mitochondrial malate dehydrogenase into oxaloacetate, during which NAD + is reduced with two electrons to form NADH. Oxaloacetate is then transformed into aspartate (since oxaloacetate cannot be transported into the cytosol) by mitochondrial aspartate aminotransferase.

Which is more energy efficient glycerol phosphate or malate aspartate?

The glycerol-phosphate shuttle transports NADH across the outer mitochondrial membrane, while the malate-aspartate shuttle transports NADH across the inner mitochondrial membrane. c. The malate-aspartate shuttle is a less energy-efficient means of transporting metabolites across the mitochondrial membrane. d.

Which is the primary enzyme in the glutamate-aspartate antiporter?

glutamate-aspartate antiporter in the inner membrane. The primary enzyme in the malate-aspartate shuttle is malate dehydrogenase. Malate dehydrogenase is present in two forms in the shuttle system: mitochondrial malate dehydrogenase and cytosolic malate dehydrogenase.