Lecture 2 (Membrane Transport)

Question 1

Osmotic Pressure

Answer 1

• Force require to oppose movement of water by gradient

Question 2

Osmosis

Answer 2

• Water moves across by simple diffusion
• Water flows toward higher solute conc.
• Aquaporins
  
  • membrane channel protein allow for water

Question 3

Ion Channel Classification

Answer 3

• Selectivity
  
  • what ion goes through
• Gating
  
  • What opens the channel

Question 4

Membrane Transport Class.

Answer 4

• Active
  
  • w/ atp
  • ex. Na+ K+ pump
• Passive
  
  • only gradient

Question 5

Facilitated Diffusion

Answer 5

• Passive transport = only gradient
• w/ membrane protein
• ex. Glucose Transporter

Question 6

Primary Active Transport

Answer 6

• w/ ATP
• Ex. NA+ K+ pump
  
  • establish Na + K gradient
  • K+ high inside/ low outside
  • Na+ high outside/ low inside

Question 7

Secondary Active Transport

Answer 7

• uses energy of Na+ gradient
• ex. Na Glu cotransporter in digestive track

Question 8

Carrier Protein Traits

Answer 8

• Saturation
  
  • all the carriers bound/ transport rate max
• Competitive Inhibition
  
  • other ligand binds and tales up carriers

Question 9

Epithelia

Answer 9

• tissues that form barrier between ext. and int. env
  -polarized
• capable of directional transport

Question 10

Epithelial Transport

Answer 10

• Can be directional
  
  • By different proteins expressed on apical(towards lumen) + basolateral(towards ECF) surfaces