1. November 19, 2015 Bell Work: What is a concentration gradient?
Objective:
The student will be able to…
Distinguish between active and passive transport.
Explain the function of a sodium-potassium pump and explain its importance.
Describe endocytosis and exocytosis.

2. Today in History
1863 President Abraham Lincoln delivered the Gettysburg Address as he dedicated a national cemetery at the site of the Civil War battlefield in Pennsylvania.
1919 The Senate rejected the Treaty of Versailles.

3. Attendance and Passes

4. Cell Transport
Active Transport

5. Active Transport
The transport of a substance across the cell membrane against its concentration gradient.
Requires the use of energy
Supplied by ATP
adenosine triphosphate

6. Active Transport
Can use carrier proteins, but transports substances against their concentration gradient
Called pumps

7. Sodium Potassium Pump Found in animal cells
In a complete cycle, it transports three sodium ions out of a cell and two potassium ions into a cell
Na+ (sodium)
K+ (potassium)
Carrier protein

8. Sodium Potassium Pump
Sodium ions have a higher concentration outside of the cell
Potassium ions have a higher concentration inside a cell
Actively transports both sodium and potassium
Energy used to power the sodium potassium pump is ATP

9. Sodium-Potassium Pump
Three sodium ions inside the cell bind to the sodium potassium pump. A phosphate group is removed from ATP and also binds to the pump.
The pump changes shape, transporting the 3 Na+ ions across the cell membrane and releasing them outside the cell.
Pump is exposed to the surface of the cell. 2 K+ ions outside the cell bind to the pump. The phosphate group is released causing the carrier protein to change shape.
The pump is exposed to the inside of the cell. The 2 K+ ions are transported across the cell membrane and released inside the cell.

10. Sodium Potassium Pump

11. Movement in Vesicles
Many substances are too large to be transported by carrier proteins
Proteins
Polysaccharides
Moved across the membrane in vesicles

12. Endocytosis Movement of a substance into a cell by a vesicle
Cell membrane forms a pouch around a substance.
Pouch closes and pinches off from the membrane to form a vesicle
May fuse with lysosomes or other organelles.

13. Endocytosis

14. Exocystosis
Movement of a substance from the inside of a cell to the outside of a cell
Vesicles fuse with the cell membrane, releasing their contents.
Use exocytosis to export proteins that are modified by the Golgi Apparatus

15. Exocytosis

16. Membrane Receptor Proteins
Proteins used to communicate with other cells in the body

17. Receptor Proteins
A protein that binds to a specific signal molecule, enabling the cell to respond the signal molecule
Most are embedded in the lipid bilayer of the cell membrane
The portion of the protein that fits the signal molecule faces the outside of the cell

18. Function of Receptor Proteins
Changes in permeability
When coupled with an ion channel, the binding of a signal molecule to the receptor protein causes the ion channel to open.
Important in the nervous system

19. Function of Receptor Proteins

20. Functions of Receptor Proteins
Second Messengers
When activated, acts as a signal molecule in the cytoplasm
Amplifies the signal of the first messenger
Can change function of the cell by:
Activating enzymes
Triggering a series of biochemical reactions in a cell
Change permeability by opening ion channels in the cell membrane.

21. Function of Receptor Proteins

22. Function of Receptor Proteins
Enzyme Action
Act as an enzyme
When a signal molecule binds to a receptor protein, it may speed up chemical reactions inside the cell
Activate other enzymes
Triggers other chemical reactions within a cell

23. In Da Club- Membranes and Transport

24. Vocabulary Worksheet
Complete the Worksheet

25. Cell Transport Worksheet
Complete the questions using a complete sentence.

26. Ticket Out
What is active transport?