Aerobic Metabolism

Aerobic respiration requires oxygen in order to generate energy (ATP). It is the preferred method of pyruvate breakdown from glycolysis and requires that pyruvate enter the mitochondrion in order to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (Adenosine Triphosphate), by substrate-level phosphorylation, NADH and FADH2.

Simplified reaction: C6H12O6 (aq) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l)
ΔG = -2880 kJ per mole of C6H12O6

The reducing potential of NADH and FADH2 is converted to more ATP through an electron transport chain with oxygen as the "terminal electron acceptor". Most of the ATP produced by aerobic cellular respiration is made by oxidative phosphorylation. This works by the energy released in the consumption of pyruvate being used to create a chemiosmotic potential by pumping protons across a membrane. This potential is then used to drive ATP synthase and produce ATP from ADP. Biology textbooks often state that 38 ATP molecules can be made per oxidised glucose molecule during cellular respiration (2 from glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system).[2] However, this maximum yield is never quite reached due to losses (leaky membranes) as well as the cost of moving pyruvate and ADP into the mitochondrial matrix and current estimates range around 29 to 30 ATP per glucose.

Aerobic metabolism is 19 times more efficient than anaerobic metabolism (which yields 2 mol ATP per 1 mol glucose). They share the initial pathway of glycolysis but aerobic metabolism continues with the Krebs cycle and oxidative phosphorylation. The post glycolytic reactions take place in the mitochondria in eukaryotic cells, and in the cytoplasm in prokaryotic cells.

Glucocorticoid Hormone

Glucocorticoid hormone predominately affects the metabolism of carbohydrates and to a lesser extent, fats and proteins, Glucocorticoid are made in the outside portion of the adrenal glands and it’s chemically classed as steroids.

Action of Glucocortocoid hormone

Glucocorticoid hormones are steroid hormones that influence nutrient metabolism, These hormones activate genes for proteins involved in process such as the synthesis of glucose, the breakdown of proteins, and the mobilization of fats.

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Glucocorticoid hormone predominately affects the metabolism of carbohydrates and to a lesser extent, fats and proteins, Glucocorticoid are made in the outside portion of the adrenal glands and it’s chemically classed as steroids.

Action of Glucocortocoid hormone

Glucocorticoid hormones are steroid hormones that influence nutrient metabolism, These hormones activate genes for proteins involved in process such as the synthesis of glucose, the breakdown of proteins, and the mobilization of fats.

Glucocorticoid hormones are secreted by endocrine glands into the blood stream. They enter cells through transporters in the plasma membrane, once inside the cytosol the hormone molecules can bind to glucocortocid receptors, which function as transcription factors that activate genes. The binding of the hormone causes proteins that were bound to the receptor such as the heat shock protein hsp90 to be released.

Release of HSP90allows two receptors to bind and form a dimer as well as exposing a nuclear localization signal on the receptor.The receptor dimer is then allowed to enter into the nucleus through a nuclear pore.

The receptor dimer is able to bind to a specific DNA sequence regions called glucocortocid response elements, or GREs,that are near target genes.The GREs function as enhancers, so that binding of a receptor dimer to a GRE activates transcription of the nearby target gene.