PHS 3341 Lecture Notes - Lecture 2: Ependyma, Interneuron, Schwann Cell
Document Summary
Facilitated diffusion net flux goes from higher to lower concentration. Example: sodium-potassium atpase, breaks down the atpase enzyme and uses water to help hydrolyze. The energy from that is transferred to the transporter. It establishes a sodium-potassium gradient, high sodium on outside and high potassium on the inside. Can bind up to 3 sodium ions, atp hydrolysis causes a conformational change and allows the 3 ions to come out low affinity for sodium so they pop off on the outside. High affinity for potassium, 2 binding sites, causes conformational change that pops off the phosphate and goes back to original to release the potassium on the inside *low affinity for potassium now. It establishes that concentration difference that will cause a charged difference and sets up our gradient. Glucose can cross via facilitated diffusion because it is higher on the outside.
