lipids. Carbohydrates are aldehyde or ketone compounds with multiple hydroxyl groups. They make up most of the organic matter on earth because of their multiple roles in all forms of life. First, carbohydrates serve as energy stores, fuels, and metabolic intermediates. Starch in plants and glycogen in animals are polysaccharides that can be rapidly mobilized to yield glucose, a prime fuel for the generation of energy. ATP, the univer- sal currency of free energy, is a phosphorylated sugar derivative, as are many coenzymes. Second, ribose and deoxyribose sugars form part of the structural framework of rna and DNA. The conformational flexibility of these sugar rings is important in the storage and expression of genetic information. Third, polysaccharides are structural elements in the cell walls of bacteria and plants, and in the exoskeletons of arthropods. In fact, cellulose, the main constituent of plant cell walls, is one of the most abundant organic compounds in the biosphere. Fourth, carbohydrates are linked to many proteins and lipids. For example, the sugar units ofgl-onorin, an integra/ membrane protein, give red blood cells a highly polar anionic coat
Recent studies have revealed that carbohydrate units on cell surfaces play hey roles in cell-cell recognition processes. Fertilization begins with the binding of a sperm to a specific oligosaccharide on the surface of an egg. The adhe- sion of leukocytes to the lining of injured blood vessels and the return of lymphocytes to their sites of origin in lymph nodes further illustrate the importance of carbohydrates in recognition processes. Carbohydrates have entered the limelight as information-rich molecules, full of signifi cance in development and repair
Monosaccharide Monosaccharide is another term for a simple sugar, such as glucose, which is not linked to any other sugars Common monosaccharides include Glucose Mannose Fructose Ribose Galactose Erythrose
Monosaccharide Monosaccharide is another term for a simple sugar, such as glucose, which is not linked to any other sugars. Common monosaccharides include: Glucose Mannose Fructose Ribose Galactose Erythrose
Monosaccharide nomenclature are the simplest sugars, having the formula (CH2O)n. The smallest molecules usually considered to be monosaccharides are those with n= 3 Category 3- --Triose Tetrose Pentose 5678 Hexose Heptose Octose
Monosaccharide nomenclature ◼ are the simplest sugars, having the formula (CH2O)n. The smallest molecules usually considered to be monosaccharides are those with n = 3 ◼ Category ◼ 3-------------Triose ◼ 4-------------Tetrose ◼ 5------------- Pentose ◼ 6--------------Hexose ◼ 7--------------Heptose ◼ 8--------------Octose
Monosaccharides containing an aldehyde group are called aldoses Monosaccharides containing a ketone group are called ketoses Monosaccharides that form five member rings are called furanoses Monosaccharides that form six member rings are called pyranoses
•Monosaccharides containing an aldehyde group are called aldoses. •Monosaccharides containing a ketone group are called ketoses. •Monosaccharides that form five member rings are called furanoses. •Monosaccharides that form six member rings are called pyranoses