Cell Membranes Flashcards
1
Q
What does a cell membrane consist of?
A
- Phospholipid Bilayer
- Channel proteins
- Carrier Proteins
- Cholesterol
- Glycoproteins
- Glycolipids
2
Q
Describe the phospholipid bilayer.
A
- Made up of two layers of phospholipids
- Phospholipid contains a hydrophilic phosphate head and a hydrophobic tail consisting of two fatty acids
- The phospholipid contains proteins which are randomly distributed throughout the bilayer
- It also contains glycoproteins and glycolipids
3
Q
How does the arrangement of the phospholipids affect the function of the cell membrane?
A
The hydrophobic tails mean that the membrane doesn’t allow water-soluble substances through it.
4
Q
What is a glycoprotein?
A
A protein with a polysaccharide chain attached.
5
Q
What is a glycolipid?
A
A lipid with a polysaccharide chain attached.
6
Q
Describe the location of cholesterol and its function.
A
It is located between phospholipids, forming bonds between them. These bonds make the membrane more rigid.
7
Q
Define hydrophobic.
A
Repels water
8
Q
Define hydrophilic.
A
Attracted to water
9
Q
Define osmosis.
A
Diffusion of free water molecules across a partially permeable membrane down a concentration gradient (high to low).
- A higher concentration of solute molecules means there is a lower concentration of water and vice versa
