Ch4 Phospholipid bilayer

Question 1

Structure of cell surface membrane

Answer 1

1. double layer of phospholipid molecules
2. intrinsic proteins - channel and carrier
3. extrinsic proteins
4. membrane contains cholesterol
5. glycolipids and glycoproteins

Question 1

Molecules that can move through phospholipids

Answer 1

1. non-polar
2. lipid soluble
3. small molecules
4. gases

Question 2

Phospholipid structure

Answer 2

1. hydrophilic phosphate head
2. hydrophobic fatty acid tails

Question 3

3 Functions of cholesterol

Answer 3

1. reduce lateral movement of molecules
2. make membranes less fluid at high temperature
3. prevent leakage of water and dissolved ions

Question 4

Molecules can’t move across csm

Answer 4

1. not soluble in lipids
2. too large for channels
3. polar- repelled by hydrophobic tails
4. same charge as protein channels

Question 5

Intrinsic protein function

Answer 5

1. structural support
2. associate with glycolipids for cell receptors
3. help cells adhere together

Question 6

Molecules that can move through channel proteins

Answer 6

1. ions
2. water-soluble

Question 7

Molecules that can move through carrier proteins

Answer 7

1. substances that are actively transported
2. substances through facilitated diffusion

Question 8

Glycolipid function

Answer 8

1. maintain stability of membrane
2. help cells attach to form tissues
3. recognition sites
4. receptors for chemicals

Question 9

Glycoprotein functions

Answer 9

1. help cells attach to form tissues
2. recognition sites
3. receptors for hormones and neurotransmitters

Question 10

Fluid mosiac model

Answer 10

Fluid- phospholipids move relative to one another(flexible)

Mosaic- proteins embedded vary in shape size and pattern

Question 11

Functions of bilayer

Answer 11

1. forms impermeable barrier to water-soluble substances
2. makes membrane flexible and self-sealing
3. allows cell to maintain different concentrations either side
4. allow lipid-soluble substances to enter and leave