Aerobic respiration is a biological process that takes energy from glucose and organic compounds to create a molecule called ATP using oxygen.Aerobic respiration has four stagesGlycolysis –
·Process occurs in the cytoplasm;
·A six-carbon glucose molecule is converted to two, 3-carbon molecules of pyruvate
·This process occurs in the cytoplasm.
·In order to initiate the process, 2 molecules of ATP are consumed. Four molecules of ATP and 2 molecules of NADH are produced;
2.Formation of acetyl coenzyme A –
·Process involves shuttling pyruvate molecules into mitochondrion
·Each pyruvate molecules is oxidized to carbon dioxide and a 2-carbon acetyl group.
·The carbon dioxide is released as a waste product, and the 2-carbon acetyl group is bound to coenzyme A and brought into the mitochondrion;
3.The citric acid cycle –
·Each of the 2-carbon acetyl groups produced from the original glucose molecule is bonded to a pre-existing molecule of oxaloacetate to form citrate (i.E. Citric acid).
·These two citric acid molecules are gradually oxidized, and the hydrogen ions are bound to NAD to form NADH and to FAD to form FADH2.
·Oxaloacetate is produced when the last carbon atom is released in the form of carbon dioxide;
·Two ATP molecules are synthesized for each glucose molecule entering the cell.
4.Electron transport chain and chemiosmosis –
·The electrons removed from the molecules in glycolysis and citric acid follow a series of cytochromes on the mitochondrial membrane,
·Hydrogen ions (protons) are pumped across the inner membrane of the mitochondrion.
·These protons flow through ATP synthase enzyme molecules, and thereby release energy which drives the formation of 34 ATP molecules.Sliding muscle model:"During muscle contracion the thin actin filaments slide over the thick myosin filaments when calcium is present the blockage active site of actin clears.StepB:power stroke:myosin head pivot pulling the actin towards the center.StepC:the bridge detaches when a new ATP binds with the myosin.