1. Vocabulary Part 1 Solute – molecules being dissolved in a solution Solvent – substance doing the dissolving in the solution (usually water) Concentration – amount of solute per unit solvent Diffusion – Movement of molecules (solute) from an area of greater concentration to an area of lesser concentration. Concentration Gradient – the difference in concentrations across a space or a membrane Equilibrium – there is no NET movement of molecules across a space or membrane

2. Vocabulary Part 1 Permeable – molecules can go through membrane Selectively Permeable (aka Semipermeable)— movement of molecules is selective based on size, polarity, and charge Impermeable – molecules cannot go through membrane Facilitated Diffusion — molecules move down the concentration gradient with the help of a protein in the cell membrane. No energy required. Active Transport -- molecule uses a protein in the cell membrane to move against the concentration gradient. Energy required.

3. Vocabulary Part 2 Osmosis – diffusion of water through a semipermeable membrane. Hypotonic – less concentrated Hypertonic – more concentrated Isotonic – equal concentrations Plasmolysis – when a cell collapses on itself because it lost too much water Cytolysis -- when a cell bursts because it has taken in too much water (more common in animal cells…why?)

4. Vocabulary Part 2 Turgor Pressure – pressure in a plant cell due to water flowing in Contractile Vacuole – vacuoles that pump water out of a cell to keep a concentration gradient present. – Example: freshwater fish (is hypertonic to environment). Pumps water out Water Potential – how much water a solution has. Water will always move from high water potential to low water potential – High Water Potential – a lot of water in a solution, so it is very dilute – Low Water Potential – not a lot of water in a solution, so it is very concentrated

6. Another Type of Active Transport way in which a cell takes in big molecules or gets rid of big molecules Requires energy (ATP) how some of our immune cells “eat” bacteria how some of our cells secrete packaged proteins made in the Rough ER Endocytosis (in) Exocytosis (out)

8. Exocytosis