Answer:
Because DNA polymerase can synthesize DNA strands in 5' to 3' direction only.
Explanation:
The 5' end of one DNA strand is present opposite to the 3' end of the other strand. But DNA polymerase enzyme can elongate the primers in 5' to 3' direction only. Formation of a phosphodiester bond between the existing nucleotide and the incoming nucleotide requires the free 3'OH. This 3' OH serves in the nucleophilic attack during the formation of the bond.
Therefore, the lagging strand is synthesized discontinuously in the form of short DNA fragments. These are called Okazaki fragments. Primers are formed for short distances which in turn are elongated by DNA polymerase to form the Okazaki fragments. On the other hand, the synthesis of the leading strand occurs continuously in the same direction in which the replication fork moves.
Answer:
Explanation:
NADH and FADH2 are both electron carriers of the electron transport chain. NADH gives up its electrons starting from Complex I, which has a higher energy level compared to other complexes. Energy is given off to pump protons across the membrane by the time electrons are transferred to ComplexIII. More electrons are pumped across the membrane as electrons move to Complex IV. Because NADH commenced giving up its electrons from Complex I (higher energy level complex), more protons are pumped across the membrane gradient, which enables ATP synthase with more power to produce 3ATP molecules per NADH molecule.
On the other hand, 2 molecules of ATP are generated by FADH2 because it starts by giving up its electrons to ComplexII. It missed a chance to pump protons across the membrane when it passed Complex I. By the time the electrons reach Complex IV, less protons have been pumped. The lesser the protons to power ATP synthase, the lesser the ATP molecules produced.
In the citric acid cycle (also
known as Kreb’s Cycle), the enzyme that catalyzes oxidative decarboxylation reactions
is α-Ketoglutarate dehydrogenase. The oxidative decarboxylation reaction is the
irreversible stage of the citric acid cycle; it generates NADH (equivalent of
2.5 ATP), and regenerates the 4C chain (CoA is excluded).
All of these components are reservoirs of carbon. The cycle is usually discussed as four main reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels).
I think, Lipogenesis is a common for organic molecules because the intermediate Acetyl-CoA is formed in most metabolic processes. Lipogenesis involves the formation of fatty acids from Acetyl-CoA. Acetyl-CoA is an intermediate stage in metabolism of simple sugars, such as glucose, which is the preferred source of energy for most living organisms.
