AP Biology - 2024 Cheat Sheet

AP Biology – 2024 Cheat Sheet Unit 1 Unit 2 Unit 3 Chemistry of Life Cell Structure & Function Cellular Energetics Water has hydrogen bonds = fun, special properties! Cohesion (water molecules stick to each other) Adhesion (water molecules stick to other surfaces) Surface tension (bugs walk on water!) Hydrolysis = cleave monomer bonds; dehy. synt. = form DNA and RNA: made of nucleic acids, genetic information Nucleotides made of (1) deoxy/ribose, (2) phosphate grp, (3) nitrogenous base. Proteins: made of amino acids; order of the polypeptide protein’s structure and function. Carbohydrates: made of sugar monomers; store energy! Lipids: nonpolar, vary in saturation; found in cell membrane Organelle mania: ribosomes make proteins; ER detoxes, makes lipids; Golgi complex folds, packages proteins; mitochondria powerhouse of cell; lysosomes expels waste Inner membrane folds → increase surf. area… more ATP made! more resources, more waste expelled = win, win! High surface area + smaller volume = ideal ratio for cells Phospholipid bilayers are (p)icky: nutrients pass on their own, some need channel proteins to chaperone Small nonpolar (N2, O2, CO2) easily pass; large polar don't Passive transport = high to low conc. w/o ATP cost Facilitated diffusion uses proteins to move H2O, Na+, K+, etc Active transport = low to high. conc. w/ ATP cost (bike up hill) Endosymbiosis theory: organelles merged>form new species Enzymes lower activation energy ⇒ catalyze chem rxn Enzymes meet substrate @ active site Enzymes love certain pH, temperature, concentration; otherwise they'll be less efficient or denature ● Competitive inhibitors (compete for active site) and noncompetitive inhibitors (sabotage active site binding) = BAD ● PHOTOSYNTHESIS – 2 parts: (1) chlorophylls charge electrons in photosystems I and II w/ light energy; (2) Calvin cycle powers carb. production @ stroma using electrons ● Cell respiration (need O2) & fermentation (don't need) make ATP ● CELL. RESPIRATION: transfer of electrons → proton gradient → ATP produced → organism uses up energy → cycle repeats! ● Big takeaway: organisms always need energy to function! Cell Communication & Cell Cycle Heredity Gene Expression & Regulation ● SIGNALING types: paracrine = nearby cells, endocrine = long distances, autocrine = within own cell ● SIgnal transduc.: reception → transduction → response ● Reception: ligand (molecule) binds to cell memb. receptor (e.g. ion-gated channel, G-protein coupled receptor) ● Transduction: signal amplifies w/ help of messengers ● Response: gene transcription activates/some other way ● Negative feedback = reduce stimulus (insulin & glucose). ● Positive feedback = increase response (oxytocin & birth) ● Cell cycle: three stages of interphase (G1, S, G2) before it enters into mitosis ● Mitosis: cell duplicates entire genome → identical daughter cells ● Meiosis: di→haploid set of chromosomes (n) ● Meiosis I: homologous chromosomes cross over (swap bits) and split (X X >>> X and X) ● Meiosis II: sister chromatids (X >>> \ and /) ● Crossing over & indep. assortment = more genetic diversity ● Mono/dihybrid crosses = handy tool to predict inheritance patterns for autosomal/sex-linked genes. ● Genotype = genetic makeup, phenotype = appearance ● Pedigrees – use to track traits across multiple generations! ● Environment can affect phenotype: weight, melanin, fur color… ● Human genetic disorders – caused by mutated alleles, chromosome changes (nondisjunction), etc ● DNA replicates 5’ to 3’-style, semi-conservative way ● Enzyme mania: helicase = unwinds; topoisomerase = prevents coiling; DNA polymerase = builds DNA molecule; ligase = combines fragments in lagging strand. ● Transcription: DNA copied into RNA; processing involves (1) GTP cap and poly-A tail addition + (2) intron splicing ● Translation: ribosome reads mRNA ⇒ protein! ● Gene expression – regulated by transcription factors (eukaryotic) or operons (prokaryotic). ● DNA mutations ⇒ protein loses/gains function (or unaffected) ● Gel electrophoresis: separates DNA fragments by size ● PCR: amplifies DNA segments ● Bacterial transformation: introduces DNA to bacterial cells. Natural Selection Ecology FRQ Tips Homeostasis = maintain internal equilibrium, respond to env. Net gain in energy = growth in an organism! Endotherms: use heat → int. temps. (exotherms can't) Some factors limit populations; popns create s (logistic) curve Simpson's Diversity Index: calculates ecosystem diversity More biodiversity in ecosys. = more resilient to disruptions Kinds of species interactions: commensalism, mutualism, parasitism, predator-prey, competition, etc. ● Going up a trophic level = only 10% energy transferred; most energy lost via heat ● Read. The. Question. Carefully. (read directions carefully) ● Figure out which are worth the most points, the least points, will take the longest, will be the quickest… then prioritize! ● Identify and graph/draw questions = quickest to respond to (don’t require complete sentences) and get out of the way ● Skip the fluff and go straight to the point ● Label your responses (a, b, c, …) ● COMMIT TO YOUR ANSWER! Erase “might” and “possible” and “I think” from your vocabulary ● If possible, always give an example Unit 4 Unit 7 Reproductive success = evolutionary fitness Competition + selective pressure ⇒ natural selection Random events (mutations) & genetic drift drive evol. Use Hardy-Weinberg equation to predict equilib. freqs! Common ancestry links lots of organisms Phylogenetic trees, cladograms: relates diff. lineages Extinction: provides newly available niches. Variation: affects population dynamics Unit 5 Unit 8 Unit 6