CELL MEMBRANES Flashcards
1
Q
What are the tails of a phospholipid made of?
A
Two fatty acids
2
Q
Is the head of a phospholipid hydrophobic or hydrophilic?
A
Hydrophilic - Polar
3
Q
Are the tails of a phospholipid hydrophobic or hydrophilic?
A
Hydrophobic - Non-polar
4
Q
What is the head of a head of a phospholipid made of?
A
Glycerol and a phosphate group
5
Q
PHOSPHOLIPID BILAYER
A
- Acts as a barrier for polar and charged particles.
- Allows the passage of non-polar, lipid soluble particles by simple diffusion.
- Selects what enters and leaves the cell
6
Q
CHOLESTEROL
A
- Regulates and maintain fluidity.
- Stabilises membrane.
7
Q
CHANNEL PROTEIN
A
- Allow the passage of polar, charged substances by facilitated diffusion.
8
Q
CARRIER PROTEIN
A
- Allow the passage of large substances by facilitated diffusion.
- Allow the passage of any substance against the concentration gradient by active transport.
9
Q
GLYCOPROTEINS
A
- Act as antigens for the immune system
- Have a role in cell signalling and cell recognition
- Act as a receptor/receptor site
- Involved in cell adhesion
10
Q
GLYCOLIPIDS
A
- Act as an antigen.
- Recognition of cells.
11
Q
What are the roles of a surface cell membrane?
A
- Separate cell from environment
- Control entry / exit of molecules
- Phospholipid bilayer allows the
passage of non polar / lipid soluble molecules - Endocytosis / Exocytosis
- Cell recognition
12
Q
What are the roles of membranes within cells?
A
- Compartmentalisation
- Isolates DNA
- Forms vesicles
- Surrounds vacuole
13
Q
What is cell signalling?
A
The communication between cells.
14
Q
Describe and explain cell signalling?
A
- Communication between cells
- Signal molecule released from one cell by exocytosis
- Binds to receptor/glycoprotein
- On the plasma membrane of target cell
- The receptor and signal molecule are specific
- Signal molecule and receptor have complementary shapes
- Bonding of signal molecule to receptor triggers response inside cell
