1. Control of Material Movement
Terminology
Solute
Substance being dissolved.
Solvent
Dissolving substance.
Solution
Mixture of solute in a solvent.
Concentration
Solute substances compared to total substances.
Example: 1 g Na+ in 99 ml of water
1/100 (1%) solute concentration
Solute
Solvent

2. Control of Material Movement
Concentration gradient
The difference between the solute concentrations of two solutions separated by a semipermeable membrane (barrier).

3. Control of Material Movement
Going with the concentration gradient
Movement of molecules across a membrane from a solution of high solute concentration to a solution of low solute concentration.

4. Control of Material Movement
Going against the concentration gradient
Movement of molecules across the membrane from a solution of low solute concentration to a solution of high solute concentration.

5. Neutral substances:
oxygen, carbon dioxide Nonpolar molecules:
lipids
Water-soluble molecules:
ions (H+, Na+, K+, Ca++, Cl–)
Polar molecules
glucose, water

6. Control of Material Movement
Passive Definition Method of moving molecules through a membrane without energy from the cell.

7. Control of Material Movement
Passive
Types
Simple Diffusion
Movement of nonpolar or neutral solutes with the concentration gradient without using a transmembrane protein.

8. Control of Material Movement
Passive
Facilitated Diffusion (Transport)
Movement of water soluble solutes with the concentration gradient using a Channel protein.

9. Control of Material Movement
Passive
Types
Osmosis
Movement of water from an area of high water to an area of low water concentration using an Aquaporins protein.

10. OSMOSIS WITH GLUCOSE

11. OSMOSIS
TONICITY Definition The concentration of solutes in a solution of two fluids separated by a membrane.

12. OSMOSIS
TONICITY Isotonic (iso = equal) The two fluids separated by a membrane are equal in solute concentration.

13. OSMOSIS
TONICITY Hypertonic (hyper = high) The fluid on one side of a membrane is higher in solutes than the other fluid.

14. OSMOSIS
TONICITY Hypotonic (hypo = low) The fluid on one side of a membrane is lower in solutes than the other fluid.

15. ISOTONIC SOLUTIONS

16. Control of Material Movement
Active Transport Definition Use of energy (ATP) to transport molecules into or out of the cell going against the concentration gradient.

17. ACTIVE TRANSPORT
Molecule/Ion Transport Carrier proteins move molecules or ions through the plasma membrane against the concentration gradient.

18. Active Transport Bulk Transport Endocytosis
Membrane vesicle forms around a substance outside the cell and brings it into the cell.

19. Active Transport Bulk Transport Exocytosis
Vesicle forms around a substance inside the cell and fuses to the membrane for secretion.

20. endocytosis
exocytosis a
coated pit b c d f e

22. CELL JUNCTIONS
Animal Cell Junctions Tight Function Joining of plasma membrane proteins creating a barrier to prevent flow between cells.

23. CELL JUNCTIONS
Adhesion (Anchoring, Desmosomes) Function Intercellular filaments join plasma membranes to allow stretching.

24. CELL JUNCTIONS
Gap (Communication) Function Joining of two adjacent membrane channel proteins for exchange of signals and nutrients.