chem review

• atom: smallest unit of life
• element: an atom with specific number of protons
• molecule: 2+ atoms bonded together
• organic molecule: molecules with carbon and hydogen
• chemical bonding: electrons are transfered or shared between atoms to fill the outer shell of electrons
• polar molecules: uneven sharing of electrons, has positive and negative sides, and aysmetrical
• nonpolar molecules: even sharing of electrons, symmetrical, neutral
• hydrogen bond: hydrogen atom with a slight positive charge and electronegative atom of another molecule
• cohesion: water molecules stick to one another
• adhision: water molecules stick to materials other than water (dew on leaf)
• surface tension: measure of the difficulty of breaking the surface of a liquid
• A lot of energy and substantial heat is needed to break waters hydrogen bonds
• specific heat: the energy required to change temp
• hydrophilic: dissolves in water molecules
• solvent: capable of dissolving many substances
• hydrophilic: (non polar) no regions of positive or negative charges (oil)
• water dissociation: when water separates into two different ions (one H+ and OH- ions)
• acids: molecules that donate H+ to solutions (H+>OH-)
• bases: molecules that accept H+ and remove them from the solution (H+<OH-)
• pH scale: way to describe how acidic or basic a solution is (0-14)
• macromolecules: made up of hundreds of thousands of molecules
• types of macromolecules:

  1. lipids
  2. carbohydrates
  3. proteins
  4. nucleic acids
• Lipids (not true polymers)

  Monomer: fatty acids

  Polymers: triglyceride (fat)

  Atoms: C, H, O
• Carbohydrates:

  Monermer: monosaccharides

  Polymers: polysaccharide

  Atoms: CxH2xOx
• Proteins:

  Monomer: Amino Acids

  Polymer: polypeptide

  Atoms: C, H, O, N, S
• Nucleic Acids:

  Monomer: Nucleotide

  Polymer: Nucleic Acid

  Atoms: C, O, N, P
• What is this?

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• What is this?

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