Lecture 67 Flashcards
What determines the selectivity of a channel is the physical and _____ properties of the permeant allowing for _____ binding within the channel (very brief binding before passing through.)
Physical and CHEMICAL properties of the permeant allowing for TRANSIENT binding
Carriers and Transporters are never open to ____ sides of a membrane at the same time, but undergo BIG conformational changes to allow for passage of the permeant.
Never open to BOTH sides of a membrane at the same time
Facilitated diffusion is also considered ______, and the direction of flux is determined by the relative ______ _____.
Also considered UNIPORT, and the direction of flux is determined by the relative CONCENTRATION GRADIENT.
Primary and Secondary active transport require ______. Whereas Primary uses _____, Secondary uses the _____ _____ of one molecule to move the other molecule.
Both require ENERGY. Whereas Primary uses ATP, Secondary uses the CONCENTRATION GRADIENT of one molecule to move the other
GLUT transporters in response to insulin is considered an example of _______ diffusion.
FACILITATED
F-class ATPases are located in the inner ______ membrane, and can move Protons in both directions (make and use ATP.) V-class ATPases can ONLY use ATP, and they are responsible for _______ lysosomes. P-class ion pumps are so named because they have a ______ intermediate. They are much simpler than the other two classes, and are the class to which ____/____ATPases belong. ABC superfamily is a unique ATPase calss in that these ATPases tend to transport _____ rather than ions.
F-class are located in the inner MITOCHONDRIAL membrane. V-class are responsible for ACIDIFYING lysosomes. P-class have a PHOSPHORYLATED intermediate and are the class to which SODIUM/POTASSIUM ATPases belong. ABC Superfamily tend to transport MOLECULES rather than ion.
F-class ATPases are the ones that MAKE ATP, but can move/pump protons bidirectionally, which depends on the direction of ______ one of its subunits. Movement of about 10 Portons down their gradient can produce ____ ATP.
Which depends on the direction of ROTATION of one of its subunits. Can produce 3 ATP
P-class Sodium/Potassium ATPases can be inhibited at the Potassium binding site by _____.
OUABAIN
The sodium/potassium ATPase can be inhibited by cardiac _____ (binding at the potassium binding site,) Ouabain is a water soluble version and _____ is a liposoluble version (obtained from the Foxglove plant).
Can be inhibited by cardiac GLYCOSIDES, which ouabain is a water soluble version of and DIGITALIS is a liposoluble version of.
Cardiac glycosides increase the force of heart contraction by ______ the sodium concentration inside the cell which _____ the operation of the Sodium/Calcium exchanger ( Secondary active transport responsible for Calcium efflux.)
Increase the force of contraction by INCREASING the sodium concentration inside the cell which INHIBITS the operation of Sodium/Caclium exchanger
There are two major types of Ca-ATPases which are both ____-class:
- SERCA (2 Ca per ATP) = Sarco and Endo-plasmic reticulum Ca-ATPase
- PMCA (1 Ca per ATP) = Plasma Membrane Ca-ATPase
Both are P-class
MDR (Multi Drug Resistance protein) belongs to the _____ superfamily, as do CFTR (cystic fibrosis transmembrane regulator) and TAP complex (ER peptide transport - Transporter associated with Antigen Processing). The MDR is up-regulated in tumor cells and they increasingly pump out Chemo drugs.
ABC
ABC transporters have 2 ______ domains
2 HOMOLOGOUS domains
The sodium/potasisum ATPase is the primary source of energy for ______ active transporters, as it increases the sodium gradient.
Primary source of energy for SECONDARY active transporters
