DLA #2: Membrane and Gas Transport (Note Cards + Sheet on CFTR SECRETION AND ABSORPTION)

Question 1

In general terms, a partition coefficient tell us:

Answer 1

The degree of ease with which a substance wants to cross a membrane (diffuse)

Question 2

In mathematical terms, the partition coefficient is expressed as:

Answer 2

[Substance in oil] / [Substance in water]

Question 3

If their is a pc = 1, we say that

Answer 3

The substance equally exists as a solute in water and oil

Question 4

If pc > 1

Answer 4

The substance is “lipophillic”

AKA Substance prefers to be in the oil/lipid phase and will readily cross the membrane.

Question 5

If pc < 1

Answer 5

• The substance is unable to enter the oil/lipid phase.
• The substance is unable to pass through the cell membrane.

Question 6

The partition coefficient of O2 and CO2 is generally

Answer 6

• HIGH (greater than 1)
• Gasses can readily diffuse through the pm

Question 7

The partition coefficient of sugars and electrolytes are generally

Answer 7

• Low (less than 1)
• They are polar and therefore cannot readily pass the pm

Question 8

Flux is defined as

Answer 8

The rate of diffusion or flow of substances b/w two compartments

Question 9

What is the relationship b/w pc and delta G (concentration gradient)

Answer 9

Question 10

What is Fick’s First Law of Diffusion and write out the equation

Answer 10

• Fick’s First Law is an equation that explains the Flux between to compartment and the paramters governing that behavior.
• J => Flux
• P => Permeability Coefficient
• Dc => Diffusion Coefficient
• Pc => Partition Coefficient
• A => Area
• x => Distance the flux needs to take place (spans the membrane)
• Delta C => Concentration Gradient

Question 11

Permeability Coefficient is defined as

Answer 11

The degree to which a substance can pass through the membrane.

On a scale b/w 0 to 1

0 => no permeability through pm

1 => complete permeability through pm

Question 12

Reflection Coefficient is defined as:

Answer 12

How easily a substance can cross the membrane based on its reflection.

• If the substance is reflected, its RC is 1
• If the substance is not reflected, its RC is 0

Question 13

Lumen is basically

Answer 13

The inside space of an organ

Question 14

Lumen of organ and the blood are divided by

Answer 14

Epithelial cells

Question 15

The apical membrane is in contact w/

Answer 15

The luminal space

Question 16

The basolateral membrane is in contact w/

Answer 16

Interstitium and blood

Question 17

Transporters and pumps on the apical and basolateral membrane are important on epthelial cell b/c they give rise to differences in

Answer 17

Polarity

Question 18

Transport across the cells that line the hollow organs or tubes is called

Answer 18

Epithelial Transport

Question 19

The Sodium-Atpase Pump is always found at the

Answer 19

Basolateral Membrane

Question 20

Epithelial cells allow for solutes/fluid to be _______ and ______ in the body

Answer 20

Absorbed and Secreted.

Question 21

Absorption is when solutes/fluid move from the :

Answer 21

LUMEN => BLOOD

Question 22

Secretion is when solutes/fluid move from the:

Answer 22

BLOOD => LUMEN

Question 23

Tight junctions b/w epithelial cells are important because they allow for the flow of

Answer 23

Water, solutes, ions (ex Na+, Cl-)