AP Biology Exam Review-Key

CONCEPT 1 - BIOCHEMISTRY 1. CHNOPS- most common elements in all living matter 2. Bonds- ionic (transfer electrons), covalent (sharing- polar/unequal sharing and non-polar/equal sharing), hydrogen (weak bonds between hydrogen and negatively charged items), hydrophobic interactions (how non-polar compounds congregate together- lipids) 3. pH a. acid-base/ 0-14, # of H ions determines scale; logarithmic- pH 3 = 10-3 = 1/1000 b. blood- 7.4, stomach- 2, small intestine- 8; enzymes are specific to pH 4. Water properties- polarity, cohesion(attraction to other water molecules), adhesion (attraction to other charged compounds) low density when frozen, versatile solvent, high heat of fusion/vaporization; surface tension 5. Organic molecules - monomers are simplest form of all; monomers join together via dehydration synthesis (loss of water) to make polymers; polymers are broken down via hydrolysis (input of water) a. Carbohydrates- CHO 1:2:1 ratio, monomer= monosaccharides, 2=disaccharides, 3 or more= polysaccharides  Used for energy (cell respiration)  Examples (1) glucose- immediate energy to make ATP (2) starch- stored energy in plants (3) glycogen- stored energy in animals (stored in liver) (4) cellulose- plant cell w