ap bio1

• Water

  Polar molecule of H2O that forms hydrogen bonds, giving it nearly every property it has
• Most common elements in biological molecules

  • Carbon
  • Hydrogen
  • Nitrogen
  • Oxygen
  • Phosphorus
  • Sulfur
• Categories of biological molecules

  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids
• Carbohydrates

  Have a 1:2:1 ratio of carbon:hydrogen:oxygen, form rings or long chains, function as short and long-term energy storage and structural materials
• Lipids


  Nonpolar, form hydrocarbon chains and steroid rings, have a hydrogen to oxygen ratio greater than 2:1, fatty acid tails can be saturated or unsaturated
• Proteins


  Polypeptides of amino acid monomers, bend and fold through hydrogen bonding and R group interactions, have diverse cellular roles like enzymes, transport channels, and receptors
• Nucleic acids

  Formed from nucleotide monomers, include DNA and RNA
• Dehydration synthesis

  Process of forming polymers from monomers
• Hydrolysis

  Process of splitting polymers into monomers
• Cell types

  • Prokaryotic
  • Eukaryotic
• Cells

  • Stay relatively small to allow for greater surface area to volume ratio for material exchange efficiency
• Eukaryotic organelles

  • Membrane-bound
  • Part of the endomembrane system (e.g. rough ER, smooth ER, Golgi)
  • Ribosomes (made of rRNA and protein, not membrane-bound)
  • Mitochondria and chloroplasts (have double membranes, excluded due to endosymbiosis theory)
• Types of transport

  • Active (requires ATP, moves large/charged molecules against concentration gradient)
  • Passive (moves small non-polar molecules down concentration gradient by diffusion or facilitated diffusion)
  • Osmosis (water movement following concentration gradient, sometimes through aquaporins)
  • Endo/exocytosis (vesicle transport of larger molecules)
• Isotonic

  Solutions where there is no net movement of water, molecules are still in motion
• Enzymes

  Decrease the activation energy required for reactions to occur, making them more favorable, but do not change the energy difference between reactants and products
• Photosynthesis


  1. Light reaction (in thylakoid membranes of chloroplast)

  2. Calvin cycle (in stroma of chloroplast)
• Cellular respiration

  1. Glycolysis (in cytoplasm)

  2. Krebs cycle (in mitochondrial matrix)

  3. Electron transport chain (in mitochondrial cristae)
• Mitochondria are not the "powerhouse of the cell", they generate ATP through oxidative phosphorylation
• Fitness

  Organisms best suited to their environment will have a greater rate of survival and reproduction, thus passing on their genotype
• Types of cell signaling

  • Autocrine
  • Paracrine
  • Endocrine
• Signal transduction pathway

  1. Reception (often through protein modification)

  2. Transduction (amplification through phosphorylation)

  3. Response (gene expression, additional signaling, apoptosis)
• Positive feedback

  Transitions a process farther away from homeostasis
• Negative feedback


  Turns conditions to a set point, maintaining homeostasis
• Mitosis


  Creates identical daughter cells through nuclear division, maintains diploid number
• Meiosis


  Nuclear division that forms unique gametes for sexual reproduction, increases genetic diversity through pairing and crossing over of homologous chromosomes, and independent assortment
• Chromosomal disorders


  • Non-disjunction
  • Deletion
  • Inversion
  • Translocation
• DNA


  Double-stranded, with deoxyribose sugar and bases A, T, C, G
• RNA


  Single-stranded, with ribose sugar and bases A, U, C, G
• DNA replication


  Semi-conservative, with DNA polymerase synthesizing new strands in 5' to 3' direction, forming Okazaki fragments on lagging strand
• Protein synthesis


  1. Transcription (in nucleus, RNA polymerase synthesizes mRNA)

  2. Translation (at ribosome, tRNA brings amino acids to mRNA codons)
• Genetic code


  Allows for variability while emphasizing unity of all living things
• Biotechnology techniques


  • PCR
  • Gel electrophoresis
  • Bacterial transformation
  • DNA sequencing
• Evolution

  Change in allele frequency of a population over time, can occur through natural selection, mutation, small population size, non-random mating, and gene flow
• Hardy-Weinberg equilibrium

  Occurs when none of the factors causing evolution are present
• Evidence for evolution

  • Fossils
  • Biogeography
  • Homologous and vestigial structures
  • Molecular comparisons
• Speciation

  The formation of new species
• Phylogenetic trees and cladograms

  Represent evolutionary relationships between organisms
• Ecology

  Focuses on how organisms communicate and respond to their environment, and how this influences fitness
• Ecological relationships


  • Energy flow through food webs/trophic levels
  • Population growth factors (resource availability, carrying capacity)
  • Community relationships (predation, competition, symbiosis)
  • Human impacts (habitat modification, extinctions)