180 likes | 308 Views
Pumps and Carriers. Peter Maloney pmaloney@jhmi.edu. • Chemiosmotic Circuits • Rules of Thumb • Classification • Experiments in Glucose Transport • Structure and Mechanism • The Na Circuit of Mammalian Cells. Pumps and Carriers. Peter Maloney pmaloney@jhmi.edu.
E N D
Pumps and Carriers Peter Maloney pmaloney@jhmi.edu
•Chemiosmotic Circuits• Rules of Thumb• Classification• Experiments in Glucose Transport• Structure and Mechanism• The Na Circuit of Mammalian Cells Pumps and Carriers Peter Maloney pmaloney@jhmi.edu
•Chemiosmotic Circuits•Rules of Thumb• Classification• Experiments in Glucose Transport• Structure and Mechanism• The Na Circuit of Mammalian Cells Pumps and Carriers Peter Maloney pmaloney@jhmi.edu
0.2 µ The Nernst Equation EK = -(RT/zF) ln [IN] / [OUT] EK = -120 mV (912 of 377,000 K+ leave)
Rules of Thumb • Movement of only a few charges will generate a membrane potential of significant size (± 120 mV) • Internal and external concentrations do not change • If a chemical gradient forms, think carefully
•Chemiosmotic Circuits• Rules of Thumb•Classification• Experiments in Glucose Transport• Structure and Mechanism• The Na Circuit of Mammalian Cells Pumps and Carriers Peter Maloney pmaloney@jhmi.edu
Classification of Transporters http://www.biology.ucsd.edu/~msaier/transport/
GeneralNomenclature Carrier = Facilitator = Porter Common Biochemical Mechanisms Uniport (GLUT1*) = Facilitated Diffusion Antiport (OxlT*) = Exchange or Counter-transport Symport (LacY*) = Cotransport * Members of the Major Facilitator Superfamily
•Chemiosmotic Circuits• Rules of Thumb• Classification•Experiments in Glucose Transport• Structure and Mechanism• The Na Circuit of Mammalian Cells Pumps and Carriers Peter Maloney pmaloney@jhmi.edu