Chapter 20Control of the Blood Glucose

The level of blood glucose is the amount of glucose in the bloodThe level of blood glucose is expressed as millimoles per liter (mM).

The concentration of blood glucose is regulated within narrow limits:

3.89----6.11mM

Hypoglycemia: the blood glucose level blow 3.33.9 mM.

Hyperglycemia: the blood glucose level above 7.227.78mM.

Physiologic significance of stable level of blood glucoseGlucose is a major source of energy for most cells of the body.Some tissues and cells (brain, red blood cells) are almost totally dependent on blood glucose as a source of energy.Glucose is the only fuel that will supply energy to skeletal muscle under anaerobic conditions.

Glucose is also required in adipose tissue as a source of glyceride-glycerol, and it probably plays a role in maintaining the level of intermediates of citric acid cycle in many tissues.A continual supply of glucose is necessary as a source of energy, especially for the nervous system and erythrocytes.

Blood glucose is derived from the diet, gluconeogenesis, and glycogenolysis

Blood sugarThe inlet and outlet of blood sugar

Control of the blood glucose by hormones

Metabolism pathway of glucose in red blood cellsGlycolysis and 2,3-bisphosphoglycerate shunt

2,3-bisphosphoglycerate shunt result in the production of 2,3-BPG but not ATP.

The pentose phosphate pathway

glucose1, 3-BPG3-phosphoglycerate2, 3-BPG2, 3-BPG phosphatase bisphosphsglycerate mutasePhosphoglycerate kinase lactate 2,3-bisphosphoglycerate shunt

Pyruvate as a junction point

48.psd

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49.psd

50.psd

51.cdx

52.cdx

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