- Active transport is used to move big molecules and ions across the membrane because they cannot diffuse through. It is also used to move materials against a concentration gradient (for example moving materials in the opposite direction). Active transport requires the use of ATP. 
- To move big molecules (too big to diffuse through), ions(these cannot get pass the hydrophobic tails), or to move in the opposite direction of the concentration gradient. It is also used to move materials out of the cell.
- Protein pumps are an example of active transport. They are a type of protein that pumps out compounds that could psoe a threat to the cell.

Vesicles:- A bubble-like membranous structure that stores and transports cellular products, and digests metabolic wastes within the cell; an intracellular membranous sac that is separated from the cytosol (liquid component of the cytoplasm) by at least one lipid bilayer.
- Cells use these vessicles to transport things out of the cell (exocytosis) or to import things into the cell (endocytosis)- These are able to form because of the fluid and movable properties of the Fluid Mosiac Model.
external image 250px-Liposome_scheme-en.svg.png


- The process in which a substance gains entry into a cell without passing through the cell membrance. This is done with the energy from ATP. This process is used by some sigal cell organisms to get food.

- There are three different types of Endocytosis:
  • Phagocytosis
  • Pinocytosis
  • Receptor mediated endocytosis

- Process of endocytosis:

external image endocytosis.gif

Below is a video on Endocytosis:

- The process where an intracellular vescile (membrane bounded sphere) moves to the plasma membrane and fuses with it. This process can be used to transport waste, proteins, antibodies, and others outside of the cell.

- Process of exocytosis:

external image exocytosis.gif 
Below is a video on Endocytosis and Exocytosis:

Pinocytosis and Phagocytosis:


Pinocytosis and Phagocytosis are types of endocytosis. The difference between these two is that Pinocytosis is an intake of liquid particles by a cell. It is CELLULAR DRINKING. Phagocytosis however, is an intake of solid particles by a cell. IT IS CELLULAR EATING.

Below are videos on how Pinocytosis and Phagocytosis works.

Contratile vacuoles:

Contractile vacuoles are membrane-bound organelles which functions in maintaining osmotic equilibrium(liquids).

Below is a video of how Contratile Vacuoles look like.

Sodium/potassium pumps:

The function is that it moves potassium ions into and sodium ions out of a cell along a protein (or enzyme) channel.

One third of the body's energy expenditure is used in this process. It is located in the plasma membrane. It helps maintain cell potential and regulate cellular volume. supports the cell resting potential and the action potentials of nerves and muscles.

Below is a video on what Sodium Potassium pump is:

Click the link below for a more detailed information on Sodium Potassium Pump :

  • Note: ATP is the smallenergy carrying moleculethat is used within ALL living things. Once the energy is used , it becomes ADP. This is recharged back ino ATP inside the mitochondria, during respiration.**