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Task A – Biochemical compounds Many organic compounds occur in nature and are sometimes called biochemical compounds. 4 major classes of biochemical compounds: carbohydrates, carboxylic acids, proteins, and amino acids. Carbohydrates are organic compounds that contain carbon hydrogen and oxygen in the ratios: 1 Carbon: 2 Hydrogens: 1 Oxygen. They are classified as: Monosaccharides, disaccharides, and polysaccharides. Monosaccharides are carbohydrates that cannot be hydrolyzed (split by a chemical reaction with water) to simpler carbohydrate units. They are the building blocks or polymers and are often called simple sugars, the most common of which is glucose (C6H12O6). CHEMICAL FORMULAS FOR GLUCOSE Molecular Formula Empirical Formula Structural Formula C6H12O6 CH2O (Ref: 14) Disaccharides are carbohydrates up of two monosaccharide units. Two common disaccharides are sucrose and lactose. They are formed by a condensation reaction where one molecule of water condenses or is released during the joining of two monosaccharides. The type of bond that is formed between the two sugars is called a: Glycosidic bond: - a type of covalent chemical bond that joins two simple sugars via an oxygen atom. The bond may be either above the plane of the ring as in a beta glycosidic bond or below the plane as in an alpha glycosidic linkage. Lactose is a disaccharide formed through the condensation of glucose and galactose. The bond formed between the two monosaccharides is called a beta glycosidic bond. The alpha glycosidic bond, found in sucrose, differs from the beta glycosidic bond only in the angle of formation between the two sugars. Unfortunately, unlike alpha glycosidic bonds, beta-glycosidic bonds are unable to be digested by some people. Therefore, many people are lactose intolerant and suffer from intestinal cramping and bloating due to the incomplete digestion of the substance. Sucrose is found in common table sugar and is composed of glucose and fructose linked via a 1-2 alpha glycosidic bond. Glucose unit + Fructose unit = Sucrose (Ref: 14) Sucrose is an excellent preservative because it has no "reducing end" or reactive group like the other sugars. Because glucose is joined to the carbon atom labelled number two on fructose, neither monosaccharide is able to open or react with other compounds in solution. It is for this reason that sucrose is an excellent natural preservative and is found in many jarred foods including jams. Other natural sources of sucrose are found in plants such as sugar cane, sugar beets, and maple syrup. Polysaccharides are also called complex carbohydrates and can be hydrolyzed to a large number of monosaccharide units. Polysaccharides typically exist as Starch. Starch is a polysaccharide that consists entirely of glucose monomers. In starch, the glucose monomers are linked (minimally) by 1-4 linkages (this means that the number 1 carbon of one glucose is linked by a glycosidic linkage to the number 4 carbon of a second glucose. Carboxylic acids A carboxylic acid contains a carboxyl group, COOH, which has one oxygen atom doubly bonded to the carbon atom and a hydroxyl (OH) group singly bonded to the carbon atom. The carbon atom of the carboxyl group must also be attached to an organic group or a hydrogen atom. Examples of common carboxylic acids include: Ref: 12 Carboxylic acids that have long (12 to 24 carbon atom) unbranched aliphatic groups are called fatty acids.
Approximate Word count = 2097
Approximate Pages = 8.4
(250 words per page double spaced)
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