Excitable Cell

What is excitability in cells?

• Ability to divide
• Ability to absorb nutrients
• Ability to send and receive electrical signals
• Ability to replicate DNA

Which ion is most concentrated inside a neuron?

• Sodium
• Potassium
• Calcium
• Chloride

What is the concentration gradient equation?

• Gradient = [ion]in + [ion]out
• Gradient = [ion]out - [ion]in
• Gradient = [ion]in / [ion]out
• Gradient = [ion]out × [ion]in

Moving down a concentration gradient means:

• Low to high concentration
• High to low concentration
• Equal concentration
• No movement

Ion channels allow ions to move:

• Up their gradient
• Randomly
• Down their concentration gradient
• Against their charge

Which ion has the highest extracellular concentration?

• Potassium
• Sodium
• Calcium
• Chloride

What type of transport do ion channels perform?

• Active transport
• Passive transport
• Facilitated diffusion
• Endocytosis

What does the Nernst equation calculate?

• Membrane permeability
• Equilibrium potential
• Resting potential
• Ion flux

What does “z” represent in the Nernst equation?

• Ion size
• Ion charge
• Ion mass
• Ion speed

If [Na+]out = 150 mM and [Na+]in = 15 mM, what is the gradient?

• 135 mM
• 165 mM
• 15 mM
• 150 mM