cell membrane structure- lqc 2a

Question 1

structure of phospholipids

Answer 1

-Glycerol joined to two fatty acids by ester bonds
-Phosphate group

Question 2

properties of the head of the phospholipid bilayer

Answer 2

Phosphate head is hydrophilic. It is polar therefore attracts water and associates with water

Question 3

properties of the tails of the phospholipid bilayer

Answer 3

Fatty acid tails are hydrophobic. They are non-polar therefore repel water and are insoluble in water

Question 4

phospholipids form

Answer 4

the bilayer of the cell membrane

Question 5

properties of the cell membrane

Answer 5

• Fluidity – gives the membrane flexibility (eg. for phagocytosis)
• Partially permeable – so that it can regulate the substances going in and out of the cell

Question 6

proteins in the cell membrane

Answer 6

some proteins have a role in cell signalling pathways, some stabilise membrane structure

Question 7

glycolipids in the cell membrane

Answer 7

act as receptors, stabilise membrane structure

Question 8

glycoproteins in the cell membrane

Answer 8

role in cellular recognition and the immune response, act as receptors for hormones and neurotransmitters, stabilise membrane structure

Question 9

phospholipids in the cell membrane

Answer 9

form the bilayer

Question 10

cholesterol in the cell membrane

Answer 10

disturbs the close packing of the phospholipids, regulates membrane fluidity, important for membrane stability

Question 11

channel proteins in the cell membrane

Answer 11

completely span the bilayer, control the entry and removal of specific molecules from the cell