Cell Membranes

?
Why do cells need membranes?
They control the entry and exit of substances, for communication with the external environment and it contains the cells organelles.
1 of 7
What is the cell membrane composed of?
Lipids (mainly phospholipids), proteins and carbohydrates.
2 of 7
What is the fluid mosaic model?
This describes the arrangement of molecules in the membrane. In the membrane, the phospholipids are constantly moving so they are the 'fluid'. Proteins are scattered through the bilayer, like tiles in a mosaic.
3 of 7
What is the function of proteins in the cell membrane?
Proteins in the cell membrane include channel proteins and carrier proteins, which allow large molecules and ions to pass through the membrane. Receptor proteins on the cell-surface membrane allow the cell to detect chemicals released from cells.
4 of 7
What is the structure of a phospholipid?
They have a hydrophillic head and a hydrophobic tail. The molecules automatically arrange themselves into a bilayer - the heads face out towards water on either side of the membrane.
5 of 7
What is the function of phospholipids?
They form a barrier to dissolved substances. This is because the centre of the bilayer is hydrophobic, so the membrane doesn't allow water-soluble substances to diffuse through it. Small, non-polar substances(E.g co2) can diffuse through the membrane
6 of 7
What is the function of cholesterol?
They restrict the movement of the phospholipids, causing them to pack more closely together, making the membrane more stable and rigid. It also has hydrophobic regions, creating a further barrier to polar substances moving through the membrane.
7 of 7

Other cards in this set

Card 2

Front

What is the cell membrane composed of?

Back

Lipids (mainly phospholipids), proteins and carbohydrates.

Card 3

Front

What is the fluid mosaic model?

Back

Preview of the front of card 3

Card 4

Front

What is the function of proteins in the cell membrane?

Back

Preview of the front of card 4

Card 5

Front

What is the structure of a phospholipid?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

Cells
Cells
See all Biology resources »See all Cell Membranes resources »