AP Review Chapters 2-5

Fast Facts Life requires about 25 elements 4 of those make up 96% of living matter Carbon, Oxygen, Hydrogen, and Nitrogen Isotopes: different atomic forms of an element. -ex. Carbon-12 (99%), Carbon-13 (1%), Carbon-14 (<1%)

Fast Facts Water is a polar molecule, opposite ends have opposite charges. A slightly positive hydrogen is attracted to a slightly negative oxygen of a nearby molecule

Fast Facts Results of Hydrogen bonds 1) Cohesion: when a substance (water) is held together by hydrogen bonds 2) Adhesion: the clinging of one substance to another 3) Surface tension: measure of how difficult it is to stretch or break the surface of a liquid. 4) Water stabilizes temperatures because of its high specific heat.

Fast Facts Hydrophilic (hydro=water, philios=love): any substance that has an affinity to water. ionic or polar molecules Hydrophobic (phobos=fearing): any substance that repels water. Nonpolar or non-ionic Buffers: substances that minimize changes in the concentration of H+ and OH- in a sln.

Fast Facts Compounds containing carbon are said to be organic compounds. Carbohydrates: include sugars and polymers Monosaccharides (monos = single; sacchar = sugar) - molecular formula is CH2O - ex. Glucose (C6H12O6)

Fast Facts Disaccharide: two monosaccharides joined by a glycosidic linkage Polysaccharides: polymers w/ few hundred to a few thousand monomers - starch: found in plants; consists only of glucose monomers (1-4 linkage); how plants store glucose (chloroplasts) - glycogen: polymer of glucose found in animals; stored in liver and muscle cells

Fast Facts Lipids: little or no affinity for water; consist mostly of hydrocarbons - 3 families: fats, phospholipids, steroids Fat: composed of 2 parts - glycerol: 3 carbon alcohol w/ hydroxyl - fatty acids: long carbon skeletons w/ carboxyl groups

Fast Facts Phospholipids: similar to fats but have only 2 fatty acid tails; 3rd hydroxyl group joins to a phosphate group

Fast Facts Proteins are polymers constructed from the same set of 20 amino acids - called polypeptides Amino acids are bonded together by a peptide bond - carboxyl group of one amino acid connects w/ the amino group of another (dehydration synthesis)

Fast Facts

Fast Facts Four levels of protein structure - primary structure: unique sequence of amino acids - secondary structure: coils or folds that are a result of hydrogen bonds at regular intervals - a helix and b pleated sheets

Fast Facts - tertiary structure: irregular contortions from interactions between side chains (R groups) - quaternary structure: overall protein structure resulting from combining of multiple subunits

Fast Facts

Fast Facts The unique conformation endows each protein with a specific function - denaturation: protein unravels and losses its conformation - pH, [salt], temperature

Fast Facts Nucleotides are the monomers (building blocks) of nucleic acids -nucleotide = nitrogenous base + pentose (5-carbon sugar) + phosphate

Fast Facts Two families of nitrogenous bases: - pyrimidines: single ring; cytosine (C), thymine (T), and Uracil (U) - purines: double ring; adenine (A), and guanine (G)

Sample Questions Describe why water is an ideal medium for living things

Sample Questions Discuss the biological importance of each of the following organic compounds in relation to cellular structure and function in plants and animals. a. Carbohydrates b. Proteins c. Lipids d. Nucleic acids