100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
NUR968 Membrane Potentials & Action Potentials - Cell Signaling & Second Messenger Systems Test With Solution $10.99   Add to cart

Exam (elaborations)

NUR968 Membrane Potentials & Action Potentials - Cell Signaling & Second Messenger Systems Test With Solution

 10 views  0 purchase
  • Course
  • NUR968
  • Institution
  • NUR968

NUR968 Membrane Potentials & Action Potentials - Cell Signaling & Second Messenger Systems Test With Solution...

Preview 3 out of 27  pages

  • August 16, 2024
  • 27
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers
  • how are ions classified
  • NUR968
  • NUR968
avatar-seller
Smooth
NUR968 Membrane Potentials & Action
Potentials - Cell Signaling & Second Messenger
Systems Test With Solution


What is the membrane potential? - ANSWER Defined as the electrical
potential difference across a cell's plasma

How are ions classified? (2) - ANSWER 1. Cations (positively charged)

2. Anions (negatively charged)

Although all positive & negative charges establish membrane potential, what
are the 2 key players (ions)? - ANSWER 1. Sodium

2. Potassium

True or false: The net flux of ions is a continuous dynamic process (never
static) - ANSWER True

How much more permeable is the plasma membrane to potassium? -
ANSWER 100x more permeable

True or false: The Sodium Potassium ATPase Pump moves ions AGAINST
their concentration gradient - ANSWER True

The plasma membrane contains protein channels called "leak channels."
What do these do? - ANSWER They leak ions (they are always open)

Which ions are leaked is dependent on what 3 factors? - ANSWER 1. The
polarity of the electrical charge of the ion & the charge on either side of a
membrane

,2. The permeability or "selectability" (specificity) of the leak channels to an
ion

3. Concentration gradient on either side of the leak channel

With potassium & sodium, which ion has the greatest concentration INSIDE
the cell? What about OUTSIDE the cell? - ANSWER Inside = Potassium

Outside = Sodium

So, why is potassium (a cation) more likely to leak out of the cell? - ANSWER
Because of the permeability to potassium

-As potassium leaves, it takes with it a positive charge leaving the inside of
the cell "more negative". This negativity then pulls potassium back in

Recall from Module 1:

When the Sodium Potassium Pump runs, 3 Na+ move OUT; 2 K+ move IN.
What is happening inside/outside of the cell each time this happens? -
ANSWER The inside of the cell becomes more NEGATIVE & the outside
becomes more POSITIVE (Separation of Charges)

What is a key player in maintaining the concentration gradients?*** -
ANSWER Sodium Potassium Pump

-Overall, sodium is predominately on the outside of the cell

-Potassium is predominately kept on the inside

Nernst Equation

-Nobel prize in 1920

-Relates the __ __ to the electrical force

, -Electromagnetic force (EMF) __ diffusion despite the ion concentration
gradient

-EMF (mv) = +/- __log (Concentration inside/Concentration outside) -
ANSWER -Nobel prize in 1920

-Relates the MEMBRANE POTENTIAL to the electrical force

-Electromagnetic force (EMF) OPPOSES diffusion despite the ion
concentration gradient

-EMF (mv) = +/- 61log (Concentration inside/Concentration outside)

So what does the Nernst equation help us equate? - ANSWER Helps us
equate the potential created by separating ions across a membrane ("helps
us determine what the resting membrane potential is")

-Recall that electrical charges can oppose diffusion

So what is the Resting Membrane Potential (RMP)? - ANSWER The electrical
difference between the inside & the outside of the cell

What is potassium's concentration on the inside to the outside? - ANSWER
35 : 1

What is sodium's concentration on the inside to the outside? - ANSWER 0.1 :
1

True or false: If we took all of the ions on either side of the cell & ran them
through the Nernst equation & then added them up, we would theoretically
get the actual resting membrane potential - ANSWER True

Why is the Nernst Equation considered too simple or flawed? - ANSWER It
only takes into account two ions (sodium & potassium)

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller Smooth. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $10.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

80461 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$10.99
  • (0)
  Add to cart