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Modern Biology : Chapter 3. Biochemistry. Carbon Compounds. Organic compounds – primarily Carbon atoms Large, complex molecules essential for life Contributes to diversity of life Carbon bonding Has 4 valence electrons Can form single, double, or triple covalent bonds
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Modern Biology: Chapter 3 Biochemistry
Carbon Compounds • Organic compounds – primarily Carbon atoms • Large, complex molecules essential for life • Contributes to diversity of life • Carbon bonding • Has 4 valence electrons • Can form single, double, or triple covalent bonds • Can form straight or branched chains of itself • Can form rings of itself
Functional Groups • Influence characteristics of molecules • Make polar with addition of charged entities • Affect chemical reactions molecules undergo • Allow bond formation between molecules • Some of these groups are – • Hydroxyl (R-OH) • Carboxyl (R-COOH) • Phosphate (R-PO4) • Amine (R-NH2)
Large Carbon Molecules • Monomers • Small, simple molecules • Amino acid, fatty acid, nucleotide, monosaccharide • Polymer • Monomers join via condensation reactions • Polypeptides • Disaccharides • Polymers break down with hydrolysis reaction • Macromolecules -- Formed from large polymers -- Protein, lipids, nucleic acids, carbohydrates
Energy Currency • Compounds store energy in chemical bonds • Certain ones’ overall structure stores energy • ATP (Adenosine triphosphate) • NADH (Nicotinamide adenine dinucleotide) • NADPH (Nicotinamide adenine dinucleotide phosphate) • FADH2 (Flavin adenine dinucleotide)
Molecules of Life • Carbohydrates • (CH2O)n general formula n = 3–8 monosaccharides • Hundreds of glucose monomers make glycogen (animals) or starch & cellulose (plants) • Proteins • Composed of amino acids (C, H, O, N et al) • 20 essential amino acids, differ in –R groups • Amino acids joined via peptide bond between amino side of 1 & carboxyl side of another • Enzymes are protein catalysts
Molecules of Life, continued • Lipids • Large, nonpolar organic molecules • Higher ratio of C & H atoms to O atoms than sugar • Types • Fatty acids (12-28 C chain with –COOH group) • Triglycerides (3 fatty acids attach to glycerol) • Phospholipids (2 fatty acids attach to phosphate on glycerol’s 3rd carbon) • Waxes (long fatty acid attaches to long alcohol chain) • Steroids (Four fused carbon rings + functional groups)
Molecules of Life, continued • Nucleic acids • Store and transmit important info in the cell • DNA: determines traits & directs cell activities • RNA: stores/transmits info from DNA • Composed of nucleotides • Adenine, guanine, cytosine, thymine or uracil • Made of 3 compartments • Phosphate group • 5-C sugar [(deoxy)ribose] • Ring-shaped nitrogenous base