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
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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
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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
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4
Q

Why’re mitochondria called the “powerhouse” of the cell?

A
  • because of their ability to produce ATP by oxidative respiration
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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
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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
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