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22 Cards in this Set
- Front
- Back
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general features of channels
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both ends of the channel are open during passage
fast may be passive or active |
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general features of pumps
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only one end is open at a time
conformational change occurs against a gradient, ATP required |
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general features of transporters
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conformational change
slow pump movement driven by gradient or ATP |
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GLUT 1-4
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passive, facilitative diffusion
bidirectional alternating conformations |
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smaller Km =
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smaller concentration needed for transport to occur
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isoforms of GLUT 1-4 receptors differ in
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substrate specificity
substrate Km tissue distribution regulation |
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GLUT2
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very high Km and will never be saturated
found in intestine |
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GLUT4 Localization
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regulated by insulin
it is translocated from vesicle to PM triggered by insulin |
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glucose/galactose malabsorption
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no absorption in gut cells
high glucose outside cell, water will follow severe diarrhea caused(aqua porins are overpowered) |
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familial renal glucosuria
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no uptake of glucose from the urine
large amounts of glucose are secreted no change in blood glucose levels |
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gated ion channels
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facilitated diffusion
selectivity is achieved by making ion channels voltage gated, ligand gated, and signal gated. |
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the way gated ion channels are regulated
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only when certain molecules are bound, the ions pass through
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voltage-gated ion channels
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responds to changes in membrane potential
ions travel based on their size |
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Ca2+ ATPase
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phosphorylated protein intermediate
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F0F1 ATPase
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H+ transport
electron transport |
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diabetic effects on GLUT4
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there is less GLUT4/mRNA
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SGLT
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Na+ glucose transporter
glucose is pulled against the gradient |
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glucose/galactose malabsorption
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intestinal SGLT1
no absorption from gut to cells H2O stays in gut so diahrrea results fructose is an alternative diet choice |
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Familial Renal Glucosuria
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kidney SGLT2
no uptake of glucose from urine lots of glucose secreted no change in blood glucose levels |
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Long QT syndrome
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mutations in ion channels
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P-glycoprotein
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MDR1-
floppase for phospholipids and glycosphingolipids |
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MDR transporters
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transports lipophillic, planar molecules out of the cell
protects against toxins can be resistant |
