Life’s molecular diversity is based on the properties of carbonCharacteristic chemical groups help determine the properties of organic compoundsCells make a huge number of large molecules from a small set of small molecules12 3Making polymers by aDehydration reactionBreaking polymers by a Hydrolysis reactionFour major macromoleculesCarbohydratesLipids (Fats)ProteinsNucleic AcidsMonosaccharides are the simplest carbohydratesCells link two single sugars to form disaccharidesPolysaccharides are long chains of sugar unitsFats are lipids that are mostly energy-storage moleculesPhospholipids and steroids are important lipids with a variety of functionsCholesterol, 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 activityMore 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 formationA 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 lifeNucleic acids are information-rich polymers of nucleotidesSugar-phosphate backboneDNA double
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