A&P - Chapter 6 (Part 2) Flashcards
(31 cards)
Where does dialysis occur?
Across a selective permeable membrane
What does dialysis cause?
The separation of smaller solute particles from larger ones
Hemodialysis
Is to clean the blood of patients with kidney failure
What is the difference between osmosis and dialysis?
Osmosis is diffusion of water, where dialysis is diffusion of solutes
Channel mediated passive transport
Allow specific things to pass through the membrane through a channel
Are channels specific?
Yes
Channels (3)
- Channels are specific
- Channels allow membranes to be selectively permeable
- Channels may be open or closed
How are channels activated?
By a variety of stimuli
What are 3 examples of stimuli that can activate a channel?
- Chemical
- Nerve impulse
- Light
Carrier mediated passive transport
Allow one thing to pass through the membrane at a time when it is attached onto the carrier
How do membrane carriers let things pass? (4)
- They attract a substance
- Bind to the solute
- Change shape
- Release the solute out on the other side of the carrier
Are membrane carriers reversible or irr-reversible?
Usually reversible
- depends on the concentration gradient
Filtration
Movement of water and permeable solutes through a membrane
What direction is the movement of filtration?
Area of high concentration to an area of low concentration
What is the force called that pushes on the side of the membranes?
Hydrostatic pressure
What is an example of when hydrostatic pressure occurs?
During formation of urine by kidneys
Where does active transport occur?
Occurs only in living cells
- through living membranes
What direction does active transport go?
Area of low concentration to an area of high concentration
- up the gradient
What does active transport require?
Energy from ATP
What are 2 types of active transport?
- Membrane pumps
2. Transport by vesicles
What are 2 types of transport by vesicles?
- Endocytosis
2. Exocytosis
Membrane pumps
A protein complex in the cell membrane
- carrier
What do membrane pumps use energy for?
To move substances across cell membranes against their concentration gradient
What is an example of the membrane pump?
Ca/K pump