unit 1, chemistry of life

• Water might be the most amazing molecule on Earth and it can defy gravity
• Water molecule


  Two elements of hydrogen for every element of oxygen form with polar covalent bonds
• Water molecule


  • Oxygen has a partial negative charge, each hydrogen atom has a partial positive charge
  • This uneven distribution of charge results in a polar molecule
• Hydrogen bonding


  Forms between a partial positive hydrogen of one water molecule and a partial negative oxygen of another water molecule
• Liquid water


  • Hydrogen bonds are continuously breaking and reforming
• Frozen water


  • Hydrogen bonds become more stable, water molecules get pushed farther apart and are less dense, which is why ice floats on water
• Water


  • Has adhesion, cohesion, and surface tension properties
• Adhesion and cohesion of water

  Allow water to defy gravity
• Matter is made up of atoms, has mass, and takes up space
• Energy is not made up of atoms
• Atoms


  Contain protons, neutrons, and electrons
• Metabolism


  The sum of all chemical reactions that take place within an organism, including bond-breaking catabolic reactions and bond-forming anabolic reactions
• Organic molecules


  Contain carbon, which forms four covalent bonds
• Six most common elements in living things

  • Carbon
  • Hydrogen
  • Nitrogen
  • Oxygen
  • Phosphorus
  • Sulfur
• Dehydration reaction


  Used to join monomers together and form a larger polymer, removes water
• Hydrolysis reaction


  Adds water to break a polymer into monomers
• Amino acid


  Made up of one central carbon atom that forms four single covalent bonds, including to an acidic carboxyl group, a basic amino group, and an R group side chain
• Peptide bond


  Covalent bond formed between the amino group of one amino acid and the carboxyl group of another during dehydration synthesis
• Polypeptide


  Chain of many peptide bonds
• Protein structure


  • Primary, secondary, tertiary, and quaternary levels
  • Influenced by R group properties and environmental factors
• Protein denaturation


  Disruption of hydrogen bonds, affecting protein shape and function
• Roles of proteins


  • Component of cellular membranes
  • Transport
  • Recognition
  • Movement
  • Communication
• Tertiary structure


  Specific 3D shape when alpha helices and beta sheets fold further inwards due to hydrogen bonding interactions
• Quaternary structure


  Two or more separate amino acid chains interacting and bonding together
• Protein structure


  Dependent upon the chemical properties of the R group and can be influenced by environmental factors
• Hydrophilic/charged R groups


  Fold outward toward the aqueous environment
• Hydrophobic R groups


  Face the interior of the protein
• Protein denaturation


  Occurs when hydrogen bonds are disrupted, changing the protein's shape and affecting its function
• Proteins do practically everything for the cell
• Integral membrane proteins


  • Have hydrophobic regions that interact with phospholipid tails and hydrophilic regions adjacent to the heads
  • Some have specific molecular chemistry internally forming a channel
• Peripheral proteins


  • More loosely attached to the membrane, involved in cell recognition and communication
• Membrane proteins


  • Can provide anchorage for the cytoskeleton, aiding in structural support and cellular movement
• Enzyme


  Catalyzes a specific chemical reaction for a substrate, has an active site that fits the substrate
• Carbohydrates contain carbon, hydrogen and oxygen in a 1:2:1 ratio
• Monosaccharides


  Monomers that join with glycosidic bonds to form polysaccharides
• Glycosidic bond


  Covalent bond that joins monosaccharides
• Carbohydrates


  • Formed by autotrophs, disassembled by nearly all living things
  • Primary source of chemical energy for the cell
  • Serve as structural material
• Monosaccharides


  • Glucose, fructose
• Disaccharides


  • Lactose, sucrose
• Polysaccharides


  • Cellulose, chitin, starch, glycogen