The malate-aspartate shuttle is the principal mechanism for the movement of reducing equivalents in the form of NADH from the cytoplasm to the mitochondrion. THIS SET IS OFTEN IN FOLDERS WITH... 98 terms. PD Exam 2. Citrin and aralar1 are homologous proteins belonging to the mitochondrial carrier family with EF‐hand Ca 2+ ‐binding motifs in their N‐terminal domains. This system relies on transport systems for malate, aspartate, glutamate, and alpha-keto-glutarate. 17. Another shuttle (mammals) is the malate-aspartate shuttle. Electrons from NADH outside the matrix are transferred in as follows: 1. 16. l NADH + H+ produced in the glycolysis cannot directly enter the mitochondrion to pass ETS because the mitochondrial membranes are impermeable to NAD. 51 terms. In contrast, photoreceptor neurons express AGC1 and the M2 isoform of pyruvate kinase, which is commonly associated with aerobic glycolysis in tumors, proliferating cells, and some other cell types. A more efficient system of transferring electrons is the malate-aspartate shuttle and it is shown in Figure 3.64. malate-aspartate shuttle and glycerol phosphate shuttle. Predict how many ATP are formed when acetyl-CoA undergoes stages 3 and 4 of catabolism. The shuttle uses the a-ketoglutarate (a-KG)-malate exchange transporter, and the glutamate-aspartate exchange transporter, malate dehydrogenase to reduce oxaloacetate (OAA) to malate, using NADH outside (and the reverse reaction inside), and a transaminase enzyme to exchange the amino group between the glutamate/OAA and a-KG/aspartate pairs. Malate-aspartate shuttle. The malate-aspartate shuttle. MCAT Psych PE: Sensory Perception. NADH is oxidized by oxaloacetate (OAc) in cytosol to NAD +. Compare the malate-aspartate shuttle and the glycerol 3-phosphate shuttle and understand their significance in affecting the amount of ATP that can be produced from glucose. The malate/aspartate shuttle and pyruvate kinase as targets involved in the stimulation of gluconeogenesis by phenylephrine. 18. The malate-aspartate shuttle is a biochemical entity that facilitates the translocation of electrons across the membrane. Cytoplasmic malate dehydrogenase reduces oxalacetate to malate while oxidizing NADH to NAD +. hepatocytes. where is the malate-aspartate shuttle most active? Respiration Plants Mechanism Shuttle System. Previous Next. Malate Aspartate Shuttle. Shuttle System l Cytosol NADH + H+ enters mitochondria through shuttle system. The mechanisms responsible for the stimulation by phenylephrine of gluconeogenesis from dihydroxyacetone and glycerol were studied in perifused rat hepatocytes. As is apparent in the figure, this shuttle involves more steps than the glycerol phosphate shuttle, but the advantage of the malate-aspartate shuttle is … 127 terms. Home. 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