AP Biology - The Chemistry of Life Latest Update Already Passed

AP Biology - The Chemistry of Life Latest Update Already Passed 4 classes of organic molecules 1. carbohydrates 2. proteins 3. lipids 4. nucleic acids acid substance that increases the molarity of hydrogen ions in a solution, decreasing pH (simultaneously diminishes the molarity of hydroxide ions, because product of the molarities of both is always 10^-14) adhesion the tendency of water molecules to stick to other substances; enables transportation of H2O against gravity in vascular plants, because molecules stick to sides of xylem alpha helix delicate coil in polypeptide chain held in place by hydrogen bonds between every fourth amino acid amino (-NH2) nitrogen atom attached to two separate hydrogens; called "amines;" alkaline properties; important in AMINO acids amino acids organic molecules that serve as the building blocks of proteins; 20 common ones, each composed of an amino group (NH2) attached to a middle carbon attached to a carboxyl group (COOH) and an R group (variable) amphipathic substances substances with both hydrophobic and hydrophilic regions amylopectin moderately branched starch (1-6 linkages) found in plants amylose unbranched starch molecule found in plants atom the smallest unit of an element that retains its characteristic properties; composed of subatomic particles such as protons, neutrons, and electrons atomic mass the mass of an atom of a particular isotope of a particular element; equal to the number of protons plus the number of neutrons atomic number the number of protons in all atoms of a specific element