8.4 Specialized Membranes Flashcards
1
Q
What is the resting membrane potential for most cells?
A
- between −40 and −80 mV, although the potential can rise as high as +35 mV during depolarization of the cell
2
Q
Nernst Equation
A
- can be used to determine the membrane potential from the intra- and extracellular concentrations of the various ions
- E = 61.5/z * log * [ion]outside/[ion]inside
3
Q
Na+/K+ ATPase
A
- One of the main functions of the Na+/K+ ATPase is to maintain a low concentration of sodium ions and high concentration of potassium ions intracellularly by pumping three sodium ions out for every two potassium ions pumped in
- This movement of ions removes one positive charge from the intracellular space of the cell, which maintains the negative resting potential of the cell
4
Q
Why’re mitochondria called the “powerhouse” of the cell?
A
- because of their ability to produce ATP by oxidative respiration
5
Q
Outer Mitochondrial Membrane
A
- completely surrounds the inner mitochondrial membrane, with the presence of a small intermembrane space in between the two layers.
- highly permeable due to many large pores that allow the passage of ions and small proteins
6
Q
Inner Mitochondrial Membrane
A
- contains numerous infoldings, known as cristae, which increase the available surface area for the integral proteins associated with the membrane
- has a much more restricted permeability compared to the outer mitochondrial membrane
- encloses the mitochondrial matrix, where the citric acid cycle produces high energy electron carriers used in the electron transport chain