Membranes As Permeability Barriers

Question 1

What are examples of 4 hydrophobic molecules that can pass directly through the membrane ?

Answer 1

• o2
• benzene
• co2
• n2

Question 2

What are examples of 3 uncharged small polar molecules that can pass through the lipid bilayer directly ?

Answer 2

H20

• urea
• glycerol

Question 3

What coefficient would indicate that a substance has high permeability - 10^-2 or 10^-14

Answer 3

10^-2

Question 4

What is passive transport dependant on ?

Answer 4

• permeability by

- concentration gradient

Question 5

What is the equation for the net rate of transport and what does each letter indicate ?

Answer 5

J = P (C1-C2)

• P is permeability coefficient
• C1 and C2 is concentration gradients on side 1 and side 2

j- rate of passive transport

Question 6

What type of graph would indicate the relationship between increasing concentration gradients and rate of passive transport ?

Answer 6

-

Iinear graph

Question 7

If G ( free energy) gives a positive value , is transport active or passive?

Answer 7

• active

Question 8

What Does a co-transport channel mean ?

Answer 8

• more than one type of ion or molecule may be transported on a membrane transporter per reaction cycle

Question 9

What does unimportantly transporter mean ?

Answer 9

Only one type of io; or molecule is transported across the membrane

Question 10

What does anti port transporter mean ?

Answer 10

• ion/molecule is transported in different directions across the membrane