Membrane Structure and Transport

Question 1

Primary Active Transport

Answer 1

-Performed by Na+/K+- ATPase

Question 2

Secondary Active Transport

Answer 2

• Coupled to Na+/K+-ATPase
• Transports Na+ ions and a specific molecule in the cell

EX:
1) SGLT-1 –> transports Na+ ions/glucose or Na+ ion/galactose into mucosal cells

2) SGLT-2 –> Transports Na+ ion and glucose for re-uptake in kidneys (2 kidneys)
(Inhibitors of these are used for treatment of diabetes)

Question 3

ABC Transporters

Answer 3

• ATP Binding Cassette
• Allows active transport of lipid/lipid-related compounds from cystol –> extracellular space using hydrolysis of ATP

(Eukaryotes)

Question 4

CFTR

Answer 4

Cystic Fibrosis Transmembrane Conductance Regulator

• Type of ABC-Transporter, but PASSIVE transport, bc flows w gradient
• Present in epithelial cells flow w gradient into the epithelial cells from secretory duct, only time Cl- can flow back into epithelial
• People with cystic Fibrosis have a DEFICIENCY of CFTR (leads to salty sweat)

Question 5

CF

• Symptoms
• Effects
• Tests

Answer 5

Cystic Fibrosis

-Newborns salty skin

Symptoms:

1) poor growth/low weight
2) Recurrent lung infections
3) Chronic pancreatitis
4) Steatorrhea (excess fat in poop)
5) Male infertility

Effects:
-High concentration of NaCl in sweat

Test:
-Sweat test