Starch, digestion glucose from

Diabetic patients have reduced antioxidant defences and suffer from an increased risk of free radical-mediated diseases such as coronary heart disease. EC has a pronounced insulin-like effect on erythrocyte membrane-bound acetylcholinesterase in type II diabetic patients (Rizvi and Zaid, 2001). Tea polyphenols were shown to possess anti-diabetic activity and to be effective both in the prevention and treatment of diabetes (Choi et al, 1998 Yang et al, 1999). The main mechanism by which tea polyphenols appear to lower serum glucose levels is via the inhibition of the activity of the starch digesting enzyme, amylase. Tea inhibits both salivary and intestinal amylase, so that starch is broken down more slowly and the rise in serum glucose is thus reduced. In addition, tea may affect the intestinal absorption of glucose. 

Fig. 2.2 Enzyme reactors prepared by LbL assembly (A) reactor on quartz plate for color-indication of glucose (B) multi-enzyme reactor for starch digestion on ultrafilter. Adapted from [26], M. Onda etal, Biotechnol. Bioeng. 1996, 57, 163 and [27], M. Onda et al.,J. Ferment. Bioeng. 1996, 82, 502.

The embryonic axis and the endosperm in cereals are separated by the shieldshaped scutellum (a modified cotyledon). Its role is to absorb the products of starch digestion from the endosperm, convert them to sucrose and transport this to the growing embryo. Glucose is absorbed by the scutellum both passively... 

Humans have enzymes in saliva and pancreatic juices that break apart the a-l,4-glycosidic bonds of starches but not the j8-l,4-glycosidic bonds of cellulose. Thus, humans cannot digest cellulose. Animals such as horses, cows, and goats can obtain glucose from cellulose because their digestive systems contain bacteria that provide enzymes to break apart j8-l,4-glycosidic bonds. 

Unlike cellulose, which is also a long chain of glucose molecules, starch can be split by the digestive enzymes of the body. When either amylose or amylopectin are split, dextrins are formed. Dextrins may vary in length from five or more glucose molecules, and the final product of enzymatic splitting of starch is glucose. 

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