Cell Membrane

Question 1

What molecule has a polar glycerol head and a non polar fatty acid tail?

Answer 1

Phospholipid

Question 2

What is the combination of a carboxyl carbon and its hydrocarbon tails In a lipid called

Answer 2

fatty acyl group

Question 3

What is the difference between a saturated and unsaturdated fat

Answer 3

unsaturated fats contain carbon-carbon double bonds whilst saturated fats only contain single bonds

Question 4

What does an increase of saturated fats do to the cell membrane?

Answer 4

increases membrane fluidity

Question 5

Fatty acyl groups of glycerophospholipids bind to which functional groups of glycerol-3-phosphate at C1 and C2?

Answer 5

OH groups

Question 6

what is a sphingolipid?

Answer 6

complex phospholipids with a core hydrophobic structure of ceremide, which is composed of a sphingosine head and a long-chain fatty acid chain

Question 7

What molecule contains a hydrophobic tail, an amine group and a C-1 Hydroxyl group?

Answer 7

a Sphingolipid

Question 8

What are the 3 types of sphingolipid?

Answer 8

sphingomyelins,

cerebrosides and gangliosides

Question 9

which disease involves an absence of hexoaminidase causing ganglioside accumulation in the brain, destroying nerve cells?

Answer 9

Tay-Sachs disease

Question 10

Which micellar like complex consists of water soluble cavity with a hydrophobic shell?

Answer 10

liposomes

Question 11

What are the two main functions of membrane proteins?

Answer 11

1. Transport Of Molecules Across Membranes

2. Transduction Of Signals Across Membranes

Question 12

How can electrostatic and hydrogen bound peripheral/extrinsic proteins be disrupted from their polar interactions?

Answer 12

adding salts or changing pH

Question 13

Which type of protein interacts extensively with hydrocarbon chains of membrane lipids?

Answer 13

integral/intrinsic proteins

Question 14

Which type of protein span the lipid bilayer?

Answer 14

integral/intrinsic proteins

Question 15

what are proteins with attached carbohydrate groups that play an important role in cellular recognition and the immune response called? ( they act as receptors for hormones and neurotransmitters)

Answer 15

glycoproteins

Question 16

what is the term for the carbohydrate and glycolipid coating on the outer surface of the plasma membrane?

Answer 16

glycocalyx

Question 17

what are the three functions of glycoproteins?

Answer 17

1. cell to cell recognition
2. cell adhesion
3. binding specific substances

Question 18

what is membrane fluidity controlled by

Answer 18

fatty acid composition (unsaturated fats increase membrane fluidity) and cholesterol content

Question 19

what does the unsaturation of fatty acyl chains result in, in terms of membrane fluidity?

Answer 19

greater membrane fluidity (due to the ‘kinks’ pushing the adjacent molecules away, which helps fluidity)

Question 20

what does increasing the amount of cholesterol in the membrane do ?

Answer 20

decreases membrane fluidity

Question 21

what are the 6 functions of membrane proteins?

Answer 21

1. transport proteins
2. intercellular junctions
3. enzyme docking sites
4. protein receptor sites
5. cell to cell recognition
6. cytoskeleton anchoring points to ECM

Question 22

What are the anchoring junctions that allow cell to cell adhesion called?

Answer 22

desmosomes

Question 23

what behave like glycoproteins and act as surface receptors and stabilise the membrane ?

Answer 23

glycolipids

Question 24

what molecule disturbs the close packing of phospholipids and helps regulate the membranes fluidity?

Answer 24

cholesterol

Question 25

what are the names of the special protein channels that allow water in and out of a cell

Answer 25

aquaporins