Membrane structure + function II

Question 1

What is major function of plasma membrane?

Answer 1

Barrier, transport, signal transduction

Question 2

What is major function of inner mitochondrial membrane?

Answer 2

Energy transduction

Question 3

What is major function of outer mitochondrial membrane?

Answer 3

Barrier

Question 4

What is major function of RER?

Answer 4

Translation protein processing

Question 5

What is major function of SER?

Answer 5

Synthesis of complex lipids

Question 6

What is major function of Golgi?

Answer 6

Post-translational modification + processing for secretion

Question 7

What is major function of nuclear membrane?

Answer 7

Attachment of chromatin

Question 8

What is major function of lysosomes?

Answer 8

Hydrolytic enzymes

Question 9

What is major function of peroxisomes?

Answer 9

Fatty acid oxidation

Question 10

What are two groups of passive membrane transport?

Answer 10

Non mediated

Carrier mediated

Question 11

What is non-mediated transport?

Answer 11

Passive diffusion
Diffusion through pore
Driven by conc gradient

Question 12

What is carrier mediated transport?

Answer 12

Aided by carrier

Uniporter=carry one molecule

Question 13

What is active membrane transport?

Answer 13

Carrier mediated

Transport molecules against conc gradient

Question 14

What are 2 transporters called?

Answer 14

Antiporter

Symporter

Question 15

What is definition of Kt?

Answer 15

Measure of affinity of transporter for its substrate

Question 16

Lower Kt, the ……. the affinity of transporter for its substrate

Answer 16

Greater

Question 17

Describe the structure of glucose transporter ?

Answer 17

12 transmembrane domains

Large molecule

Question 18

What is glucose transport an example of?

Answer 18

Carrier mediated facilitated diffusion process

Question 19

Describe the kinetics of glucose transport?

Answer 19

Similar to enzyme kinetics
Specific for molecules they transport i.e. D glucose not L glucose
Exhibit saturation type kinetics

Question 20

What does active transport require?

Answer 20

Requires integral membrane proteins

Selective

Question 21

What is meant by antiport system?

Answer 21

Transports one molecule in one direction and one molecule in other direction

Question 22

What is foxglove?

Answer 22

Foxglove is a plant which has chemicals within leaves that has been used therapeutically for long time

Question 23

What is congested heart disease?

Answer 23

Is heart condition that prevents heart from beating properly

Question 24

How does foxglove help with congested heart disease?

Answer 24

Foxglove contains an active ingredient called digitalis which is cardiotonic steroid which inhibits Na+/K+ pump
Inhibition of this pump means that intracellular sodium conc increases and it will stimulate 2nd transporter called sodium calcium exchanger
This 2nd transporter pumps sodium out and calcium in

Question 25

What are 2 glucose transporters found in gut?

Answer 25

SGULT 1 and 2

Question 26

What is cellular asymmetry?

Answer 26

Cells have some polarity Different glucose transporter have been differential expressed => expressed in different parts of cells In order to maintain cellular asymmetry, there are junctions that prevent movement of membrane associated proteins

Question 27

What is rehydration therapy?

Answer 27

Replaces water lost Treats symptoms of diarrhoea Targets co transport of glucose + sodium

Question 28

What disease is associated with chloride channel?

Answer 28

Cystic fibrosis

Question 29

What is compartmentalisation?

Answer 29

Separates reactions Enables local environment to be regulated for instance pH Bring together components of enzyme activity Bring reactants together Separates pathways

Question 30

What is disease of misdirection?

Answer 30

I cell disease

Question 31

What is I cell disease?

Answer 31

Lack ability to add mannose 6 phosphate | Product taken by lysosome accumulates so cells therefore will fail to function.