Membrane Transporters

Question 1

Primary active transporters

Answer 1

use ATP to do work. Examples: Na/K pump, Ca++, H+ on cell membranes and others on organelles

Question 2

Secondary active transporters

Answer 2

use Na+ leak into cell to do work. There are much more common

Question 3

cotransport

Answer 3

moving different solute species in the same direction

Question 4

exchange transport

Answer 4

moving different solute species in the opposite direction

Question 5

non-electrogenic secondary tranporters

Answer 5

tend to equalize ion concentration, but do not change the net charge across the membrane

Question 6

electrogenic secondary transporters

Answer 6

one cycle produces a net charge transfer across the membrane. Can reserve direction depending on membrane potential

Question 7

H+/K+ exchanger

Answer 7

non-existent transporter (likely multiple transporters). Infusing K+ causes acidemia, and infusing acid cause hyperkalemia.

Question 8

glucose inside cell

Answer 8

glucose tranporter cannot pump glucose against its concentration gradient. Glucosein phosphorylated inside the cell. Thus glucose flow becomes more or less unidirectional and glucose collects inside the cells.

Question 9

2 methods for dealing with hyperkalemia

Answer 9

To encourage cells to take up the potassium from ECF you can give glucose and insulin, or give bicarbonate.