ATP-powered pumps, Ion Channels, and Transporters.
What are the three classes of transport membrane proteins?
100
Protein-mediated transport.
What transport is faster than simple diffusion, specific, and reversible?
100
P Class, V Class, F Class, and ABC superfamily.
What are the four main classes of ATP-Powered Pumps?
100
Electrochemical Gradient.
What determines the direction of the ion movement through transmembrane proteins?
100
If a positively charged molecule is transported out the cell a negatively charged molecule must also be transported out or another positively charged molecule must be transported in.
What are the two concepts of transcellular transport?
200
Simple diffusion, Facilitated transport, Active transport, and Cotransport.
What are the different mechanisms for transporting ions and small molecules across cell membranes?
200
Uniport proteins adopt two structural conformations in which the substrate-binding site can face inward or outward.
What is the general structure of uniport proteins?
200
Pumps that must be phosphorylated to be transport competent and transport ions.
What are P class pumps?
200
Electrical potential and chemical concentration gradients.
What are the two forces that constitute the electrical/chemical gradient?
200
This is caused by the apical membrane facing the outside of the cell and the basolateral membrane facing the inside of the cell.
Why is a polarized cell asymmetric?
300
Uniporters: transport a molecule down its concentration gradient (facilitated diffusion)
Synporters: couple transport of a molecule against its concentration gradient with one molecule down its concentration gradient in the same direction (cotransport/secondary active transport).
Antiporters: couple transport of a molecule against its concentration gradient with one molecule down its concentration gradient in opposite directions (cotransport/active secondary transport).
What are the three types of transporters and how do they work in general?
300
Transport protein family members can differ by their rate of transport and by expression profile dictated by cell type.
What are the different ways that transport protein family members can differ?
300
Pumps that generate low pH in lysosomes and pumps in mitochondria/chloroplasts that function as reverse pumps.
What are V class and F class pumps?
300
The use of energy by movement of an ion down its electro/chemical gradient to power the import or export of molecules against their concentration gradient.
What is the mechanism of cotransporters?
300
Na+ linked symporters in the apical membrane and Na+/K+ ATPases and uniporters in the basolateral membrane facilitate the transport of _______?
What are the different proteins involved in mediating the transcellular transport of amino acids and glucose from the intestinal lumen to the blood?
400
ATP-powered pumps couple the movement of a solute against its concentration gradient to ATP hydrolysis (active transport)
How do ATP-powered pumps work?
400
Osmosis is the movement of water across a membrane from an area of low solute concentration to an area of high solute concentration.
What is "Osmosis"?
400
Transporters that are specific for a single substrate of group of related substrates and have two transmembrane domains and two ATP-binding domains.
What are ABC superfamily transporters?
400
The change of this molecules free energy is negative.
What is the change in free energy of Na+ transport into the cell?
400
The drawing of water from the intestinal lumen into the body is the cause.
The increase in osmotic pressure created by transcellular transport of salt, glucose, and amino acids across the intestinal epithellium does what?
500
Ion Channels allow ions to flow down their concentration gradients (facilitated diffusion)
Channels in general form passages that allow water to flow down its concentration gradient (osmosis).
How do Channels work?
500
Aquaporins control osmotic pressure by opening or closing to allow water to pass through the membrane.
What controls osmotic pressure and how?
500
They transport moelcules from the cytoplasm or inner leaflet to the exoplasm or outer leaflet.
What functions do ABC transporters have?
500
Na & Glucose and HCO3(-) & Cl(-)
What are examples of symporter and antiporter systems?
500
Carbonic anhydrase and Transport proteins.
The secretion of HCl into the lumen requires what proteins to maintain a neutral cytosolic pH in the parietal cells of the stomach?