Cell Membrane and Transport Flashcards
(14 cards)
what is the function of cholesterol in the membrane
1) structural function to maintain membrane fluidity in ANIMAL cells
what are lipid rafts
1) collection of cholesterol and glycosphingolipids that create a micro-domain of membrane fluidity
2) lateral movement of membrane proteins is higher here
what are ionophores
specific class of antibiotics that disrupt the membranes of bacteria/fungus
what is nystatin
1) it is an inophore and binds to ergosterol on fungal membrane and disrupts membrane fluidity and electrochemical gradient is lost
2) animal cells have cholesterol so they are not affected*
what are lipid anchors
1) portion of a membrane protein that is strongly associated with the membrane
2) Ras, Src, and Thy-1
hydrophobic alpha helices
1) used for transmembrane proteins and integral proteins
glut2 carrier proteins
1) liver
2) pancreas
3) small intestine
GLUT4 carrier proteins
1) skeletal muscle
2) heart
3) adipose tissue
these carrier proteins are insulin responsive
Myasthenia gravis
1) AI disorder that destroys Ach receptors at NMJ
what establishes the resting membrane potential
1) K+ ion gradient through leaky channels
2) this is “set up” by Na+/K+ pumpi
E1 vs E2 of NaK Pump
1) E1 is the state where Na+ binds
2) E2 is phsorylated and Na+ leaves the cell while 2 K+ bind
P-type ATPases and their locatioins
1) NaK Pumps (ubiquitous)
2) Plasma Membrane Ca2+ pumps (PMCA) pump Ca2+ out
3) H/K Pumps: parietal cells in gastric mucousa and alpha-intercalated cells of collecting duct
What is MDR1
1) multi-drug resistant protein (P-glycoprotein) is a type of ABC-type ATPase
2) normally expressed in the liver, it transports drugs out of the cell “drug-efflux pump”
SGLT vs GLUT
1) SGLT: a sodium/glucose transporter (symporter) that uses secondary active transport
2) SGLT found on apical enterocytes to absorb glucose
3) GLUT: glucose transporter (uniporter) uses facilitated (passive) transport
4) on apical
