Comparisons of Scopes Visible light passes through specimen Electron Visible light passes through specimen Light refracts light so specimen is magnified Magnify up to 1000X Specimen can be alive/moving color Focuses a beam of electrons through specimen Magnify up to 1,000,000 times Specimen non-living and in vacuum Black and white

Prokaryote Vs. Eukaryote “before” “kernel” No nucleus DNA in a nucleoid Cytosol No organelles other than ribosomes Small size Primitive i.e. bacteria “true” “kernel” Has nucleus and nuclear membrane Cytosol Has organelles with specialized structure and function Much larger in size More complex i.e. plant/animal cell

Parts of plant & animal cell p 108-109

Cells must remain small to maintain a large surface area to volume ratio Large S.A. allows increased rates of chemical exchange between cell and environment

Animal cells have intercellular junctions: Tight junction = prevent leakage Desomosome = anchor cells together Gap junction = allow passage of material

Cell Membrane

6 types of membrane proteins

Passive vs. Active Transport Little or no Energy Moves from high to low concentrations Moves down the concentration gradient i.e. diffusion, osmosis, facilitated diffusion (with a transport protein) Requires Energy (ATP) Moves from a low concentration to high Moves against the concentration gradient i.e. pumps, exo/endocytosis

hypotonic / isotonic / hypertonic

Exocytosis and Endocytosis transport large molecules 3 Types of Endocytosis: Phagocytosis (“cell eating” - solids) Pinocytosis (“cell drinking” - fluids) Receptor-mediated endocytosis Very specific Substances bind to receptors on cell surface

Be sure to know…. Water potential problems Grid ins = 4