1. What is the difference between active and passive transport?
contrapositive-(con tra ‘pa ze tiv)- (noun)- a proposition or theorem formed by contradicting both the hypothesis and conclusion of a given theorem and interchanging them.
Oddly enough, the contrapositive of a statement is equivalent to the original statement. For example, “If a student says ‘hi’ to Mr. Cahall, then he will high-five them” is equivalent to its contrapositive, “If Mr. Cahall doesn’t high-five a student, then they didn’t say hi to him.”

2. Solutions Molecules dissolved in a liquid = SOLUTES
Liquid/fluid dissolving them = SOLVENT
This makes a SOLUTION
In a salt solution, ______________ is the solute and _____________ is the solvent
In a sugar solution, sugar is the solute and water is the solvent.
SALT
WATER

3. Concentration and Equilibrium
Solutions will spread out their dissolved molecules until they are equal throughout. The number of molecules in a certain are per unit volume is called the CONCENTRATION.
High concentration: more solutes per
unit volume
Low concentration: less solutes 
per unit volume

4. If the solutions on either side of the barrier have the same concentration we call that being at equilibrium.
At equilibrium, both the solvent and solute move back and forth across the barrier: there is always movement.

5. Passive Transport
The movement of materials across a membrane without using energy
There are three different types:
1. Diffusion – the process in which solutes move across a membrane from areas of high concentration (crowded) to areas of low concentration

6. Passive Transport
2. Facilitated Diffusion – molecules are moved across a cell membrane with the help of a protein because they are either too large or have a charge and can’t pass through the membrane
How? The proteins form a
channel like a large hold in
the membrane, this doesn’t
require any energy and the
molecules move through
the passage.

7. Passive Transport
3. Osmosis– the movement of water across a membrane. The water molecules are trying to reach equilibrium. Water is small so it can move quickly, much faster than larger molecules.
It will move to the area of higher solute concentration to help dilute it.

8. Gradients
When there is a difference in solution concentrations we say that there is a gradient.

9. ACTIVE Transport!!
Movement across a cell membrane that requires energy because it is AGAINST the concentration gradient (it moves solutes from low to high—where it’s already crowded)
There are three different types:
1. Pump – a special type of protein is used to PUSH molecules to an area of high concentration. This requires ENERGY!
An example is a Sodium and Potassium Pump. It uses ATP as energy!
This creates a gradient which the cell can use to send messages to other cells.

10. Large Particle Transport!!
1. Endocytosis (Endo=in) – a pocket (vesicle) forms around outside material and buds inward to release the material indie the cell. The vesicles are organelles called vacuoles.

11. Large Particle Transport!!
2. Exocytosis (Exo=out) – a vesicle inside the cell fuses with the cell membrane and releases its contents outside the cell.

12. Isotonic Solutions
Solute concentration is equal on inside and outside of cell
Water moves in both directions
No NET movement

13. Hypotonic Solutions
A higher solute concentration inside the cell than outside
 water flows into cell
This can cause a cell to burst

15. Hypertonic Solutions
More solute concentration outside of the cell than inside
 water flows out of cell
This can cause cell to shrink

16. Hypertonic

18. Predict what will happen….

19. Water leaves the cell and it shrivels or shrinks1.
Water leaves the cell and it shrivels or shrinks
Cell _______________________
Environment _____________________
hypotonic
hypertonic

20. Water enters the cell and it swells2.
Water enters the cell and it swells
Cell_________________________
Environment _____________________
hypertonic
hypotonic

21. Water leaves the cell and it shrivels or shrinks3.
Water leaves the cell and it shrivels or shrinks
Cell_________________________
Environment _____________________
hypotonic
hypertonic

22. Equal water entering and leaving cell so cell is in homeostasis4.
Equal water entering and leaving cell so cell is in homeostasis
Cell_________________________
Environment _____________________
isotonic
isotonic