8/25/20111Life’s molecular diversity is based on the properties of carbonCharacteristic chemical groups help determine the properties of organic compounds8/25/20112Cells make a huge number of large molecules from a small set of small molecules12 3Making polymers by aDehydration reactionBreaking polymers by a Hydrolysis reaction8/25/20113Four major macromoleculesCarbohydratesLipids (Fats)ProteinsNucleic AcidsMonosaccharides are the simplest carbohydrates Cells link two single sugars to form disaccharides8/25/20114Polysaccharides are long chains of sugar unitsFats are lipids that are mostly energy-storage moleculesPhospholipids and steroids are important lipids with a variety of functions8/25/20115Cholesterol, a steroid1 23 4Anabolic steroids pose health risksProteins are essential to the structures and functions of life • Structural proteins: are found in hair and the fibers that make up connective tissues such as tendons and ligaments.• Contractile proteins: Found in muscles• Defensive proteins: The antibodies of the immune system• Signal proteins: Such as hormones that coordinate body activity8/25/20116More proteins• Receptor proteins: may be built into cell membranes and transmit signals into cells.• Transport proteins: Like hemoglobin transport oxygen in the red blood cells.• Storage proteins: such as ovalbumin, the protein of egg white, which serves as a source of amino acids for developing embryos. General structure of an amino acidPeptide bond formation8/25/20117A protein’s specific shape determines its functionA protein’s shape depends on four levels of structure1234Linus Pauling contributed to our understanding of the chemistry of life8/25/20118Nucleic acids are information-rich polymers of nucleotidesSugar-phosphate backboneDNA double
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