Coenzyme A (CoA) is derived from th

Coenzyme A (CoA) is derived from the B vitamin pan-tothenic acid and functions primarily to transfer acetylgroups, which contain two carbons, from one moleculeto another. These acetyl groups come either from pyruvate, which, as we have just seen, is the end prod-CoASOCH3Cuct of aerobic glycolysis, or from the breakdown offatty acids and some amino acids, as we shall see in alater section.Pyruvate, upon entering mitochondria from thecytosol, is converted to acetyl CoA and CO2(Figure 4–21). Note that this reaction produces the first mole-cule of CO2formed thus far in the pathways of fuelcatabolism, and that hydrogen atoms have been trans-ferred to NAD.The Krebs cycle begins with the transfer of theacetyl group of acetyl CoA to the four-carbon mole-cule, oxaloacetate, to form the six-carbon molecule, ci-trate (Figure 4–22). At the third step in the cycle a mol-ecule of CO2is produced, and again at the fourth step.Thus, two carbon atoms entered the cycle as part ofthe acetyl group attached to CoA, and two carbons (al-though not the same ones) have left in the form of CO2.Note also that the oxygen that appears in the CO2isnot derived from molecular oxygen but from the car-boxyl groups of Krebs-cycle intermediates

Kết quả (Anh) 1:

Coenzyme A (CoA) is derived from the B vitamin pan-tothenic acid and functions primarily to transfer acetylgroups, which contain two carbons, moleculeto from one another. These reductive acetyl-CoA groups come either from pyruvate, which, as we have just seen, is the end prod-CoASOCH3Cuct of aerobic glycolysis, or from the breakdown and some amino acids offatty acids, as we shall see in section alater. Pyruvate, upon entering mitochondria from thecytosol, is converted to the reductive acetyl-CoA CoA and CO2 (Figure 4-21). Note that this reaction produces the first mole cule-of CO2formed thus far in the pathways of fuelcatabolism, and that of the hydrogen atoms have been trans-ferred to NAD. The Krebs cycle begins with the transfer of theacetyl group of the reductive acetyl-CoA CoA to the four-carbon oxaloacetate, cule, mole-to form the six-carbon molecule, ci-trate (Figure 4-22). At the third step in the cycle a mol-ecule of CO2is produced, and again at the fourth step. Thus, two carbon atoms entered the cycle as part ofthe group attached to the reductive acetyl-CoA CoA, and two carbons (al-though not the same ones) have left in the form of CO2. Note also that the oxygen that appears in the CO2isnot derived from molecular oxygen but from the car-boxyl groups of Krebs-cycle intermediates

Kết quả (Anh) 2:

Coenzyme A (CoA) is derived from the B vitamin pan-tothenic acids and functions to transfer chính acetylgroups, mà chứa two carbons, from one another moleculeto. These acetyl groups from pyruvate come hoặc, mà, as WE HAVE just seen, is the end of aerobic glycolysis prod-CoASOCH3Cuct, or from the breakdown offatty acids and some amino acids, as we shall see in alater section.Pyruvate, upon entering the mitochondria from thecytosol, acetyl CoA is converted to CO2 and (Figure 4-21). Note có this reaction produces the first mole-cule of CO2formed thì far in the pathways of fuelcatabolism, and honest hydrogen atoms trans-ferred to được NAD.The Krebs cycle begins with the transfer of acetyl CoA theacetyl to the group of four-carbon mole-cule, oxaloacetate, to form the six-carbon molecule, ci-trate (Figure 4-22). At the third step in the cycle a mol-ecule of CO2is Produced, and again at the fourth step.Thus, two carbon atoms as part ofthe vào cycle acetyl group attached to CoA, and two carbons (al-though not the same ones ) have left in the form of CO2.Note cũng vẻ có là oxygen in the molecular oxygen CO2isnot derived from but from the car-boxyl groups of Krebs-cycle intermediates