1. Cell Transport

2. Cell
Cell- Smallest unit of life
Analogy:

3. Barrier to Entry

4. Cell Membrane
Functions:
Encloses, protects, regulates entry to cell

5. Cell Membrane Properties:
Selectively Permeable: allows certain molecules in and out
Lipid Bilayer: two layers of lipids arranged in a certain way
Polar versus Nonpolar: has both a charged and a non-charged region

6. Movement across the membrane
Two types:
Passive Mechanisms: Do not require cellular energy
Active Mechanisms: require cellular energy in the form of ATP (adenosine triphosphate)

7. (Simple Diffusion) Passive Transport
From high concentration to low concentration (across the concentration gradient)
Examples:

8. Facilitated Diffusion
Passive Transport
Requires carrier protein
Still from high concentration to low concentration
Molecules are too big to move across the membrane

9. Osmosis Movement of water across a membrane
The solute does not move across the membrane

10. Filtration Forcing molecules through a membrane (without energy)
Examples:

11. Passive Mechanisms Write:
What are the main differences between the four of these mechanisms?
Share with a partner.
How are you going to remember them?!

12. Active Transport
REQUIRES ENERGY!

13. Active Transport Goes against the concentration gradient
From lower concentration to higher concentration
Requires ATP
Utilizes carrier proteins
Examples: Sugar, Amino acids… larger molecules

14. Endocytosis
Molecules that are too large to enter, come in through a vesicle

15. Exocytosis
Secreting substances via a vesicle to the outside of the cell

16. Active Mechanisms What are they?
Differences between the different types?
How are you going to remember them?

17. Concept Map time
Step 1: Generate a list of the words that you think are important from what was presented today.
Step 2: Sort them into categories
For example: Endocytosis: phagocytosis, pinocytosis, receptor-mediated endocytosis
Step 3: Connect- Organize the categories in boxes with arrows (so it looks like a concept map)
Step 4: Elaborate- we will discuss our concept maps

18. Questions Which of the following processes includes all others?
Osmosis
Diffusion of a solute across a membrane
Facilitated diffusion
Passive Transport
Transport of an ion down its gradient

19. Questions
An artificial cell consisting of an aqueous solution enclosed in a selectively permeable membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose.
1. Which solute(s) will exhibit a net diffusion into the cell?
Environment:
0.01 M sucrose
0.01 M glucose
0.01 M fructose
“Cell”:
0.03 M sucrose
0.02 M glucose

20. Questions
An artificial cell consisting of an aqueous solution enclosed in a selectively permeable membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose.
2. Which solute(s) will exhibit a net diffusion out of the cell?
Environment:
0.01 M sucrose
0.01 M glucose
0.01 M fructose
“Cell”:
0.03 M sucrose
0.02 M glucose

21. Questions
An artificial cell consisting of an aqueous solution enclosed in a selectively permeable membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose.
3. In which direction will there be a net osmotic movement of water?
Environment:
0.01 M sucrose
0.01 M glucose
0.01 M fructose
“Cell”:
0.03 M sucrose
0.02 M glucose

22. Questions
An artificial cell consisting of an aqueous solution enclosed in a selectively permeable membrane has just been immersed in a beaker containing a different solution. The membrane is permeable to water and to the simple sugars glucose and fructose but completely impermeable to the disaccharide sucrose.
4. After the cell is placed in the beaker, which of the following changes will occur?
The artificial cell will become more loose (flaccid)
The artificial cell will become more swollen (turgid)
Some water molecules will flow into the cell, but the majority will flow out of it
Despite the ability of sucrose to cross the membrane, eventually the two solutions will become isotonic
Environment:
0.01 M sucrose
0.01 M glucose
0.01 M fructose
“Cell”:
0.03 M sucrose
0.02 M glucose

23. Questions
The concentration of a certain molecule inside and outside the plasma membrane of a cell was measured over time. The data are shown in the graph below.
True statements about this molecule
Include which of the following?
This molecule is hydrophobic
This molecule is necessary for cellular function
This molecule required the expenditure of energy to enter the cell
This molecule entered the cell using diffusion
This molecule is embedded into the plasma membrane