= glucose + fructose (linked by α1→2 glycosidic bond); sucrose is NOT A REDUCING SUGAR and is cleaved in the intestine by sucrase.

Sucrose

L-Ribulose, also known as β-L-ribulose, belongs to the class of organic compounds known as pentoses. These are monosaccharides in which the carbohydrate moiety contains five carbon atoms. L-Ribulose is an extremely weak basic (essentially neutral) compound (based on its pKa).

Figure 10-4. The aldotetroses contain two chiral carbon atoms, each of which may exist in an R- or S- form, giving rise to four stereoisomers. The two erythrose isomers are mirror images (enantiomers), as are the two threose isomers.

Polysaccharides such as starch, glycogen, and dextrans are all stored in the liver and muscles to be converted to energy for later use. Amylose and Amylopectin are polysaccharides of starch. Amylose has a linear chain structure made up of hundreds of glucose molecules that is linked by a alpha 1,4 glycosidic linkage.

The digestive enzyme α-amylase is responsible for the breakdown of the starch molecule into maltotriose and maltose, which can be used as sources of energy. Amylose is also an important thickener, water binder, emulsion stabilizer, and gelling agent in both industrial and food-based contexts.

Starch with elevated levels of amylose, compared to the typical wild‐type lines, can be termed high‐amylose starch (HAS). So far, HAS types from mutant cereal grains such as wheat, maize, rice, barley, as well as potato tuber have been developed.

what is glycogen and why it is more efficient in delivering energy than starch. The branching in glycogen is more frequent than amylopectin, glycogen has branching every 8-10 units of glucose, while amylopectin has 12-20 glucose molecules between each branch.

Glycogen is similar to starch in that it is a storage form of glucose. Glycogen, however, is the carbohydrate storage form in animals, rather than plants. It is even more highly branched than amylopectin, as shown below.

Structurally glycogen is very similar to amylopectin but with more α-1,6 linkages – every 8-12 glucose units. This means it is very branched and so more compact than amylopectin, and it can be broken down very rapidly to provide the glucose fuel needed for cellular respiration.

The combination of two monosaccharides produces disaccharides. Polysaccharides are formed by combining a large number of glucose monomers together. The main difference between sugar and starch is that sugars are disaccharides or monosaccharides whereas starch is a polysaccharide.

Starch is the stored form of sugars in plants and is made up of a mixture of amylose and amylopectin (both polymers of glucose). Plants are able to synthesize glucose, and the excess glucose, beyond the plant’s immediate energy needs, is stored as starch in different plant parts, including roots and seeds.

All digestible simple sugars and starches eventually get converted to glucose in the body. Most types of cells use glucose as their main fuel source.

Diets high in refined starches are linked to a higher risk of diabetes, heart disease and weight gain. In addition, they can cause blood sugar to spike rapidly and then fall sharply. This is especially important for people with diabetes and prediabetes, since their bodies can’t efficiently remove sugar from the blood.

How do potatoes affect blood sugar levels? Like any other carb-containing food, potatoes increase blood sugar levels. When you eat them, your body breaks down the carbs into simple sugars that move into your bloodstream.

The findings suggest that eating two eggs per day, 6 days a week can be a safe part of a healthy diet for people with type 2, according to Nicholas Fuller, PhD, from the Boden Institute Clinical Trials Unit, University of Sydney, Australia.