Health Effects and Recommended Intakes of Sugars

Gelatin Rich Food

Ever since people first discovered honey and dates, they have enjoyed the sweetness of sugars. In the United States, the natural sugars of milk, fruits, vegetables, and grains account for about half of the sugar intake the other half consists of sugars that have been refined and added to foods for a variety of purposes. Added sug- brown sugar refined white sugar crystals to which manufacturers have added molasses syrup with natural flavor and color 91 to 96 percent pure sucrose. confectioners'...

Glucose in the Body

Uptake Glucose Cells

The primary role of the available carbohydrates in human nutrition is to supply the body's cells with glucose to deliver the indispensable commodity, energy. Starch contributes most to the body's glucose supply, but as explained earlier, any of the sugars can also provide glucose. Glucose plays the central role in carbohydrate metabolism. The next two sections provide an overview first of the pathways glucose can follow in the body and then of the ways the body regulates those pathways. A...

The Complex Carbohydrates

Starch Molecule

The simple carbohydrates are the sugars just mentioned glucose, fructose, and galactose, either singly or paired with glucose. In contrast, the complex carbohydrates contain many glucose units and a few other monosaccharides strung together as polysaccharides. Three are important in nutrition glycogen, starches, and fibers. Glycogen is a storage form of energy in the animal body starches play that role in plants and the fibers of plants serve as structural elements in stems, trunks, roots,...

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Examples Legumes Vegetables

Starch and Cellulose Molecules Compared Small Segments The bonds that link the glucose molecules together in cellulose are different from the bonds in starch and glycogen . Human enzymes cannot digest cellulose. See Appendix C for chemical structures and descriptions of linkages. When the hormonal message Release energy arrives at the storage sites in a liver or muscle cell, enzymes respond by attacking all the many branches of each glycogen simultaneously, making a surge of fuel available....

The Simple Carbohydrates

Numbering Carbon Atoms Glucose

The following list of the six sugars most important in nutrition symbolizes them as hexagons and pentagons of different colors. Three are single sugars or monosaccharides Glucose. Fructose. Galactose. Three are double sugars or disaccharides Maltose glucose glucose . Sucrose glucose fructose . Lactose glucose galactose . The three monosaccharides important in nutrition all have the same numbers and kinds of atoms, but in different arrangements. These chemical differences account for the...

The Chemists View of Carbohydrates

To understand the structure of carbohydrates, look at the units of which they are made. The sugars most important in nutrition are the 6-carbon monosaccharides known as hexoses. Each contains 6 carbon atoms, 12 hydrogens, and 6 oxygens written in shorthand as C6H12O6 . Each atom can form a certain number of chemical bonds with other atoms Carbon atoms can form four bonds. Chemists represent the bonds as lines between the chemical symbols such as C, N, O, and H that stand for the atoms see...

Sugars Starches and Fibers

DIGESTION AND ABSORPTION OF CARBOHYDRATES The Processes of Digestion and Absorption Lactose Intolerance A Preview of Carbohydrate Metabolism The Constancy of Blood Glucose HEALTH EFFECTS AND RECOMMENDED INTAKES OF SUGARS Health Effects of Sugars Recommended Intakes of Sugars HEALTH EFFECTS AND RECOMMENDED INTAKES OF STARCH AND FIBERS Health Effects of Starch and Fibers Recommended Intakes of Starch and Fibers student, quietly studying a textbook, is seldom aware that within his brain cells,...

Digestion and Absorption of Carbohydrates

Absorption Food With Capillaries

The ultimate goal of digestion and absorption of sugars and starches is to dismantle them into small molecules that the body can absorb and use chiefly glucose. The large starch molecules require extensive breakdown the disaccharides need only to be hydrolyzed once. The initial splitting begins in the mouth the final splitting and absorption occur in the small intestine and conversion to a common energy currency glucose takes place in the liver. The details follow. The Processes of Digestion...