Intro to Electrophysiology- Lecture 14 Flashcards
What are carrier proteins?
membrane proteins that operate in cycles by binding solutes (their substrates), undergoing conformational changes that convey the solutes across the membrane, and returning to the original conformation
What are channels?
proteins that provide a transmembrane pore through which specific solutes can diffuse strictly down their electrochemical gradients
What is the Veq of Na+?
+67
What is the Veq of K+?
-91
What is the Veq of Ca2+?
+125
What is the Veq of Cl-?
-78
What is the membrane potential (membrane voltage/ Vm)?
the difference in ionic composition between the inside of the cell and the extracellular space
What is the membrane potential of cells?
-70mV
What is the equilibrium potential (Veq)?
the value of Vm where the concentration gradient and the electrostatic force are balanced
What is the Nerst equation at 30 degrees C?
58 [So]
Veq = —— x log ——
Z [Si]
When does a membrane become hyperpolarized?
when Vm becomes more negative upon the exit of cations or the entry of anions
When does a membrane become depolarized?
when Vm is made less negative by the entry of cations or the exit of anions
What is driving force?
the absolute difference between Vm and Veq
= |Vm x Veq|
What is Ohm’s law?
I = g x V
