1. Active Transport

2. Active Transport All of the previous types of transport were passive
Diffusion
Osmosis
Facilitated Diffusion
Passive transport happens from an area of high concentration to low concentration

3. Active Transport
Active transport is the movement of molecules from an area of low concentration to high concentration
This takes molecules from outside the cell and moves them inside
These processes take energy

4. Active Transport There are two main types of active transport
Pumps
Vesicles
These two processes require energy and move molecules “up” a concentration gradient

5. Cell Membrane Pumps
Membrane proteins can help both active and passive transport
Membrane proteins that assist active transport are referred to as Cell Membrane Pumps
These pumps assist charged particles into the cell

6. Cell Membrane Pumps
These pumps are a little different than the passive transport carrier proteins
These have a certain amount of binding sites
These binding sites will fill with ions or other small molicules
Once those are full, the cell uses energy to move the molecules into or out of the cell

7. Cell Membrane Pumps The energy that is used by these pumps is ATP
ATP is a molecule that supplies energy when it is broken apart
After it is broken the cell can use the energy that is released

8. Sodium Potassium Pump
One example of active transport in animal cells is the sodium potassium pump
This pump carries sodium and potassium up their concentration gradients

9. Sodium Potassium Pump
Sodium is an element that can be toxic to a cell in high enough concentration
Potassium is something that a cell needs for many processes however it is not always found in abundance in the environment

10. Sodium Potassium Pump
The pump starts by binding three sodium atoms from inside the cell
With some energy, the sodium ions are released from the cell

11. Sodium Potassium Pump
Next two potassium ions are attached to the protein pump
With some energy from ATP, the potassium ions are brought into the cell

13. Movement in Vesicles
Many times there are molecules that are too large to fit through the carrier proteins and membrane pumps
These macromolecules, nutrients and molecules need to be brought into the cell in other ways

14. Endocytosis
A cell can take in external fluid, large particles and dissolved particles
It does this by creating an indent in its cell membrane
The cell membrane then creates a small pouch called a vesicle
The vesicle is brought in to the golgi apparatus

15. Endocytosis
When large molecules needs to be brought into the cell, the cell goes through endocytosis
Endocytosis is the process of making a vesicle out of cell membrane

16. Endocytosis
What is actually in the vesicle determines what kind of endocytosis it is
Pinocytosis involves the movement and transport of solutes and fluids
Phagocytosis is the movement of large molecules, bacteria or viruses

17. Endocytosis
Receptor–mediated endocytosis is a specific type of active transport that only happens when receptors on the cell surface pick up specific molecules
When the receptors engulf the molecules, a coated vesicle is formed and the cell can bring it where it needs to go

18. Exocytosis
Exocytosis is the process by which a substance is released from the cell
Exocytosis is a process that requires energy to create the vesicles involved

19. Exocytosis
During exocytosis a cell takes a vesicle and fuses it with its plasma membrane
During this process a cell releases what ever was contained within the vesicle
It can be a large molecule, several small molecules or things dissolved