Question

How does a low blood glucose levels trigger the mobilization of stored fats for b-oxidation.

Answer 1

-At the time of fasting or strict diet, we basically restrict the consumption of food.

-The energy already present in the body is used up while doing activities, but a time comes when the blood glucose level lowers down and we require any substitute for glucose. This is done by b- oxidation of fatty acids.

-According to amphibolic pathway, the fatty acids are converted into Acetyl Co A, which then enters into citric acid cycle to liberate energy.

- This conversion is triggered by the low level of glucose which causes the release of hormones like epinephrine, norepinephrine, glucagon and adrenocorticotropic hormone.

- At first, the triglycerols are broken down by enzyme lipase through the process lipolysis. Thus it releases fatty acids.

-b- oxidation of fatty acids in prokaryotes takes place in the cytosol whereas, in eukaryotes it takes place in the mitochondria.

- In eukaryotes, the fatty acid undergoes number of oxidative reactions which results into the formation of 2-carbon atom containing compound, Acetyl Co A, with the liberation of one molecule each of NADH and FADH2 which will yield 5 ATP molecules.

- The Acetyl Co A then enters the citric acid cycle and then enters the ETC which forms the ATP molecules.

- so one fatty acid (containing 16 carbons) generate 129 ATP molecules.

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