QUESTION

Question

Question

Question #1

When blood glucose concentration is normal, the glucose which is filtered from the blood in the kidneys is reabsorbed back into the bloodstream by the kidney tubules, and so none is lost in the urine. But if blood glucose exceeds about 12 mmol/litre, this causes more glucose to be filtered by the kidneys than they can reabsorb. Glucose is therefore lost in the urine, and, because glucose is a powerful osmotic agent, it draws water with it, causing large volumes of sweet urine to be excreted (characteristic of diabetes mellitus). The other undesirable consequence of a persistently elevated blood glucose is that a chemical reaction (glycation or glycosylation) can occur between glucose and proteins, including the important structural proteins in cell membranes, and this can damage the membranes, producing harmful effects. Thus the action of insulin to control blood glucose prevents these undesirable effects of hyperglycaemia, and also ensures that glucose is available for use by the body's tissues.

Question #2

Dietary fiber is widely recognized an important part of the treatment and prevention of diabetes, colorectal cancer, gastrointestinal disorders, high cholesterol, heart disease and obesity. The main value of dietary fiber is that it provides bulk to the bolus moving through the digestive tract.

Soluble fiber has been shown to be able to bind bile salts which may reduce blood cholesterol levels. Low blood cholesterol levels have been associated with a reduced risk of coronary heart disease. Soluble fiber attracts water and forms a gel in the digestive tract. This slows digestion and lowers the rate of nutrient absorption from the stomach and intestine. Soluble fibers can also lower blood sugar levels in people with diabetes. Intake of soluble fiber may also improve glucose tolerance in people with diabetes. Fibers that lower blood cholesterol levels include foods such as ...