state the general molecular formula for a monosaccharide
Monosaccharide Monosaccharides (from Greek monos: single, sacchar: sugar), also called simple sugars, are the most basic units of carbohydrates.[1] They are fundamental units of carbohydrates and cannot be further hydrolyzed to simpler compounds. The general formula is C nH 2nO n. They are the simplest form of sugar and are usually colorless, water-soluble, and crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose (dextrose), fructose (levulose) and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch). Further, each carbon atom that supports a hydroxyl group (so, all of the carbons except for the primary and terminal carbon) is chiral, giving rise to a number of isomeric forms, all with the same chemical formula. For instance, galactose and glucose are both aldohexoses, but have different physical structures and chemical properties.
Cell wall The composition of cell walls varies between species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are absent from land plants. In bacteria, the cell wall is composed of peptidoglycan. The cell walls of archaea have various compositions, and may be formed of glycoprotein S-layers, pseudopeptidoglycan, or polysaccharides. Fungi possess cell walls made of the N-acetylglucosamine polymer chitin. Unusually, diatoms have a cell wall composed of biogenic silica.[1]