CLASS OF  07/03

Next class on the structure model of the plasma membrane, which is like the model of the flowing moisaico.
Plasma is responsible for what can not pass through or inside out of the cell. It is calculated by two layers of phospholipids, that delimit the cells and there are molecules of proteins immersed in that layer.

The phospholipids are composed of two tails (hydrophobic) and one head (hydrophilic). In the membrane the polar heads are exterior and tails to the interior.

The transport in and out of the cell can be done in two types:

Active Transport: type of transport that the cells will do with energy expenditure, and this expense happens so that the concentration does not disperse.

Passive Transport: type of transport that the cells will do without energy expenditure. Molecules and ions are transported naturally, from where they are most amount to the place where they are in the lowest quantity. It is also known as simple.