Drug Target 2 Ion Channels And Transporters

Question 1

What do ion channels and transporters allow

Answer 1

Allow ions and molecules to cross cell membrane

Question 2

What does cell membrane seperate and what is size of the cell membrane

Answer 2

Separates living cell from aqueous environment

Thin barrier=8nm thick

Question 3

What does cell membrane control

Answer 3

Controls traffic in and out of the cell

And allows some substances to cross more easily than other

Question 4

Describe phospholipids

Answer 4

• Phosphate head which is hydrophilic
• Fatty acid tails which is hydrophobic so is non polar
• It is arranged as a bilayer

Question 5

What is the function of the phospholipid bilayer

Answer 5

Serves as a cellular barrier

Question 6

What are the different types of transports

Answer 6

• Passive transport I.e. simple diffusion, Facilitated transport
• Active transport

Question 7

Describe the two passive transport

Answer 7

-simple diffusion- it is the diffusion of non polar, hydrophobic molecules I.e lipids
It goes from a high to a low concentration gradient
- facilitated transport- it is the diffusion of polar , hydrophilic molecules through a protein channel.
It goes from a high to a low concentration gradient

Question 8

Describe active transport

Answer 8

It goes against the concentration gradient from a low to high and uses a protein pump
It also requires ATP

Question 9

What does protein allow

Answer 9

It allows substances which cannot penetrate phospholipid bilayer to cross the membrane

Question 10

What are the two types of proteins which allow substances to go through

Answer 10

• channels and transporters
• channels are only passive and they are trans membrane proteins with fluid filled pores
• transporters are passive or active and they are transmembrane proteins which have sites that bind the substrate and facilities passage through membrane

Question 11

What is facilitated diffusion

Answer 11

• It is diffusion through protein channels and these channels only allow specific molecules to go through
• no energy is required
• from high to low concentration

Question 12

Give two examples of ion channels

Answer 12

Muscarinic Cl- channels and

Voltage active Na+ channels

Question 13

What are carrier proteins ( transporters)

Answer 13

Bind specific solute to transport them across a membrane and it is always facilitated diffusion.
Once it binds the protein changes shape

Question 14

What are the Different types of transporters

Answer 14

Uniport pore

Coupled pores

Question 15

What is uniport

Answer 15

One type of molecule is transported

Question 16

What is coupled pores

Answer 16

Two molecules transported together

Question 17

What are the two types of coupled pores

Answer 17

Symport and antiport
Symport- both molecules move in the same direction
Antiport- molecules move in an opposite direction

Question 18

Active transport

Answer 18

Cells may need to move molecules against a concentrated gradient

• shape change transports solute from one side of membrane to other
• requires ATP
• goes from a low to high conc

Question 19

Na+ / K+ ATPase

Answer 19

Move in opposite directions one in and one out e.g

. Na+ out and K+ in

Question 20

How does drugs enter the cell

Answer 20

• Through cellular drug transport
• Drugs often enter cells via either passive or active drug trasnport proteins
• some drugs are actively transported out of cells via drug transport proteins e..g multi drug resistance