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. H2O)
Covalent Bond
Types of Bonds (cont.)• Polar Covalent Bond-
– e-’s are shared unevenly– One atom holds e-’s closer (electronegativity)– H2O
• 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 bondsMethane
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
EnzymesSubstrate- (X) reactants effected by enzyme
Active Site
EnzymeEnzymes 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.)