Membrane potential

Excitable cells ____________________.

can send and receive electrical signals

Membrane potential is created by __________.

the uneven distribution of ions across the membrane

match the following ions with their description.

Sodium (Na+) – High concentration outside, Potassium (K+) – High concentration inside, Chloride (Cl-) – Typically higher outside, Calcium (Ca2+) – Low concentration inside but important for signaling.

Based on your knowledge of the concentration gradients of sodium, potassium, chloride, and calcium, predict the direction these ions will move across the membrane through open channels.

Sodium, chloride, and calcium enter the cell. Potassium exits the cell.This movement occurs due to their concentration gradients, which drive sodium, chloride, and calcium into the cell while potassium moves out.

While characterizing the effects of medical marijuana, researchers have discovered a new type of channel that contains a binding site for the active ingredient, THC, on the outside of the cell. This new receptor could be classified as _______.

a ligand-gated ion channel. THC is binding to a ligand-gated ion channel. These channels contain a binding site for a chemical messenger to bind to and then either open or close the channel.

By what process is sodium moved out of the cell?

active transport

voltage-gated ion channel

gated by a change in the charge of their surrounding environment inside the cell

ligand-gated ion channel

gated by a chemical messenger on the inside or outside of the cell

passive transport

the movement of ions or molecules across a membrane without energy expenditure, typically down their concentration gradient.

active transport

the movement of ions or molecules across a membrane against their concentration gradient, requiring energy input, often through ATP.

What is the resting membrane potential of a typical neuron?

approximately -70 mV, indicating a polarized state.

Which of the following is true regarding resting membrane potential?

It is the point where net flux is zero across the cell membrane.

Hypothesize how a reduction in the activity of Na/K /ATPase (pump) would affect the distribution of ions across the cell membrane?

Na+ would accumulate inside the cell.

Fill in the blanks. The sodium potassium pump actively transports ______ sodium ions from inside to outside the cell and ______ potassium ions from outside to inside the cell.

3, 2