What is the function of the cell membrane
Allows the cell to alter its shape and regulated the movement of materials into and out of the cell
What must living things be able to do
Control its environment
What are the 4 primary components
- phospholipids
- proteins
- cholesterol
- carbohydrates
Explains the role of phospholipids
The primary structure of the cell membrane is a phospholipid bilayer
Explain proteins
- numerous protein molecules that serve many functions (membrane transport, hormone receptors, attaching the membrane to the cytoskeleton)
- peripheral proteins are found on the surface
- trans membrane (integral proteins) pass through
Explain the cholesterol
- Has polar and non polar components
- keeps the membrane fluid like and provides stability
- part of the steroid ring is closely attached to part of the fatty acid chain on the nearest phospholipid
- immobilizes the outer surface of the membrane
- makes the membrane less soluble to very small water soluble molecules that could pass through more easily
What if there is no cholesterol in the membrane
the membrane would be too fluid, not firm enough and too permeable to some molecules at high temp
Cholesterol in simpler terms
prevents the extreme in the consistency of the cell
At low temp, what dose cholesterol do
helps separate the phospholipids so that the fatty acid chains cant come together and crystallize
Explain the carbs
- oligosaccharides link to lipid and protein components on the exterior of the cell membrane
- plays a role in cell recognition and cell-cell interactions
What is the fluid mosaic model?
- used to describe the cell membrane
- fluid: able to flow and alter shape freely
- mosaic: made up of many different parts
