Marco Learning AP Biology Unit 1

AP Biology Insta-Review Unit 1: Chemistry of Life Tiffany Jones @apbiopenguins AP Biology AP Biology students are penguins because they are Dressed for Success! You are now an AP Bio Penguin! Today’s Plan Today’s Plan: Macromolecules Water Properties Practice Questions Unit 1 Q&A Carbohydrates Composed of C, H, & O – Ratio: 1:2:1 Monomer: Monosaccharide Structural: • Cellulose: found in plant cell walls • Chitin: found in fungi cell walls & exoskeleton of arthropods Storage: • Starch: found in plants • Glycogen: found in animals Examples: Glucose, Fructose, Galactose Disaccharides: Two monosaccharides Bond: Glycosidic Linkage Examples: Sucrose, Lactose, Maltose Proteins Composed of C, H, O, N, & S Monomer: Amino Acid Hydrogen Amino Carboxyl R R group Bond: Peptide bond (between carboxyl & amino groups) R group Fold Hydrophilic Exterior Hydrophobic Interior Charged Exterior N terminus C terminus Levels of Protein Structure: Primary: • Bond: peptide bonds between amino acids • Structure: string of amino acids Secondary: • Bond: hydrogen bonds between backbone • Structure: alpha helix or beta pleated sheet Tertiary: • Bond: ANY (hydrogen, covalent, ionic, …) between R groups • Structure: final 3D structure Quaternary : • Bond: ANY (hydrogen, covalent, ionic, …) between R groups of different polypeptides Nucleic Acids Composed of C, H, O, N, & P 5’ end Monomer: Nucleotide Phosphate Nitrogenous Base Pentose Sugar Bond: Phosphodiester linkage (between phosphate and hydroxyl) Nitrogenous Bases Purine: • Double Ring • A&G Pyrimidine: • Single Ring • C, U, T 3’ end Directionality: 5’  3’; antiparallel Base Pairing H bonds A&T 2 C&G 3 DNA RNA Nitrogenous Bases A, T, C, G A, U, C, G Sugar Deoxyribose Ribose Strandedness “double” “single” Lipids Composed of C, H, O, & P (in phospholipids) All of the lipids are NONPOLAR!! Monomer: N/A Fats 3 fatty acids Phospholipids Phosphate Glycerol Glycerol 2 fatty acids Amphipathic Saturated fatty acid • • ALL single bonds Each carbon is SATURATED by hydrogen Unsaturated fatty acid • • Steroids At least one double bond NOT all carbons are SATURATED by hydrogen Four fused rings Ligand: • Intracellular Reception Polar Polar covalent bonds between oxygen & hydrogen IN the water molecule Hydrogen bonds between oxygen & hydrogen BETWEEN water molecules Cohesion/Adhesion Cohesion: • Water molecules attracted to other WATER molecules Adhesion: • Water molecules attracted to other POLAR substances Together leads to Capillary Action Universal Solvent Partial negative oxygen binds with other polar molecules (partial positive end) & to positively charged ions (cations) Partial positive hydrogen binds with other polar molecules (partial negative end) & to negatively charged ions (anions) Surface Tension Cohesion develops a “surface” based on the interaction of hydrogen bonds Allows you to skip rocks or water striders to walk on water Less Dense when Solid Hydrogen bonds inhibit compaction Ice floats; temperature buffer High Specific Heat Water must absorb or release A LARGE amount of energy to change 1 gram of water by 1°C. Evaporative Cooling Release water on surface of organism to absorb heat energy from body (and break the bonds cooling down the organism) Temperature Buffer • Coastal Regions • Body Temperature pH pH = - log [H+] As the concentration of hydronium/hydrogen ion increases, the pH decreases Multiple Choice Practice Multiple Choice Practice: Scientists examined the folded structure of a purified protein resuspended in water and found that amino acids with nonpolar R groups were primarily buried in the middle of the protein, whereas amino acids with polar R groups were primarily on the surface of the protein. Which of the following best explains the location of the amino acids in the folded protein? hydrogen Polar R groups on the surface of the protein can form ionic bonds with the charged ends of the water molecules. Polar R groups are too bulky to fit in the middle of the protein and are pushed toward the protein’s surface. Nonpolar R groups that cannot form hydrogen bonds with water are pushed into the middle of the protein. Nonpolar R groups from different parts of the protein form covalent bonds with each other to maintain the protein’s structure. Hydrophobic interaction due to attractive forces a. b. c. d. Multiple Choice Practice Multiple Choice Practice: Rosalind Franklin’s x-ray diffraction images taken in the 1950s most directly support which of the following claims about DNA? a. The ratios of base pairs are constant. b. The nucleotide sequence determines genetic information. c. The two strands of DNA are antiparallel. d. The basic molecular structure is a helix. FRQ Practice (2021 #2) Free Response Practice: Geneticists investigated the mode of inheritance of a rare disorder that alters glucose metabolism and first shows symptoms in adulthood. The geneticists studied a family in which some individuals of generations II and III are known to have the disorder. Based on the pedigree (Figure 1), the geneticists concluded that the disorder arose in individuals II-2 and was caused by a mutation in mitochondrial DNA. (a) The disorder alters glucose metabolism. Describe the atoms AND types of bonds in a glucose molecule. Follow us on your favorite social media channels! @marcolearning @apbiopenguins @marcolearning @apbiopenguins Marco Learning AP Bio Insta-Review