The cell membrane is an amazing part of our cells and our bodies. Such a thin membrane made up of two layers of the same molecule known as a phospholipid (one side is water-loving [hydrophilic], the other water-hating [hydrophobic]. There are scientists who spend their careers discovering the cool and amazing nature of our tiny little cell membranes. GOOGLE image, "Cell Membrane" What do you see???
Our Cell Membrane's are a selectively permeable 'skin' which protects the contents of the cell, but also allows molecules to pass through, most of which we need.. some of which we do not!
The videos below are a selection from youtube that I found useful for reviewing the two methods for transport of essential molecules (Oxygen, Carbon Dioxide, and water) in and out of our cells: Diffusion and Osmosis.
Diffusion is the movement of particles in a liquid or gas, from an area high concentration, to an area of low concentration.
Osmosis is the movement of water molecules through a membrane, but it occurs from an area of low concentration to an area of high concentration. Both forms of movement are "free" in that they do NOT require energy to work. Further, the movement of molecules works to create homeostasis (BALANCE) throughout the gas or liquid the molecules are in. Since these two forms of movement through the membrane do not require energy, they are known as PASSIVE TRANSPORT.
Our Cell Membrane's are a selectively permeable 'skin' which protects the contents of the cell, but also allows molecules to pass through, most of which we need.. some of which we do not!
The videos below are a selection from youtube that I found useful for reviewing the two methods for transport of essential molecules (Oxygen, Carbon Dioxide, and water) in and out of our cells: Diffusion and Osmosis.
Diffusion is the movement of particles in a liquid or gas, from an area high concentration, to an area of low concentration.
Osmosis is the movement of water molecules through a membrane, but it occurs from an area of low concentration to an area of high concentration. Both forms of movement are "free" in that they do NOT require energy to work. Further, the movement of molecules works to create homeostasis (BALANCE) throughout the gas or liquid the molecules are in. Since these two forms of movement through the membrane do not require energy, they are known as PASSIVE TRANSPORT.
ACTIVE TRANSPORT through the membrane
Active Transport is a method of transport through the cell membrane that requires the help of a carrier protein. This protein is found in the cell membrane. It works by recognizing the shape of a molecule and opening the 'doors' to the cell to allow the molecule to enter or exit the cell. This protein needs the energy molecule, ATP (Adenosine Triphosphate) in order to work.