Just Enough Chemistry for Genetics Cell Bio/Genetics Mr. Foster

Types of Bonds Ionic Bond- –Ion - atom that has gained or lost electrons (e - ’s) –Transfer of e - ’s b/t 2 atoms –Metals and nonmetals (ex. NaCl) Covalent Bond- –Share e - ’s equally –Nonmetal and nonmetal (ex. H 2 O)

Covalent Bond

Types of Bonds (cont.) Polar Covalent Bond- –e - ’s are shared unevenly –One atom holds e - ’s closer (electronegativity) –H 2 O Hydrogen Bond- –A slightly +H of a polar cov. bond in one molecule is attracted to a slightly neg. atom of another molecule (WEAK) –Ex. H with O, F, N H H O

Compounds of Life Organic- contain carbon VERY IMPORTANT Inorganic- usually do not contain carbon

Organic Form chains or rings Form strong stable bonds Form 4 bonds Methane Benzene

Compounds of Life (cont.) 1.Water –Most abundant compound in living organisms –Uneven distribution of electrons Polar molecule Give water unique characteristics –Wide range of temp. is liquid –Good solvent- dissolves many substances H H O - +

2. Carbohydrates –C, H and O –Sugar & Starches (Glucose) (Glycogen) –Functions Provide energy Contribute to cellular structure –Hydroxyl functional group (R-OH) Compounds of Life (cont.)

3. Lipids –C, H, O –Fats, oils, Waxes –Carboxyl group – (COOH) Compounds of Life (cont.) R OH ?

Compounds of Life (cont.) 4. Proteins –C,H,O and N –Amino acids- building blocks –Functional group – amine group –Functions Structure Enzymes- biological catalysts

Enzymes Substrate- (X) reactants effected by enzyme Active Site Enzyme Enzymes are very specific Enzymes are sensitive to temperature and pH

5. Nucleic Acids (DNA, RNA) –C, H, O, N, P –Building blocks Nucleotide –Functional Group- phosphate group –Functions Store genetic info. Transmit genetic info. Compounds of Life (cont.)