Membrane Transport Flashcards
How permeable is the plasma membrane of a cell to gases like CO2 , N2, O2?
Freely permeable
How permeable is the plasma membrane of a cell to small uncharged polar molecules like urea or water?
Slightly permeable
How permeable is the plasma membrane of a cell to ethanol?
Permeable
How permeable is the plasma membrane of a cell to large uncharged polar molecules like glucose and fructose?
Impermeable
How permeable is the plasma membrane of a cell to ions?
Completely impermeable
How permeable is the plasma membrane of a cell to charged polar molecules?
Impermeable
Give some examples of charged polar molecules
Amino acids, ATP, glucose6-phosphate, proteins, nucleic acids
Define bioenergetics
The transport of ions (especially H+) involved in ATP synthesis, usually at energy coupling membranes in mitochondria, chloroplasts and bacteria
Describe the typical turnover rate and abundance of membrane pumps
Pumps have low turnover rates and so are high in abundance
Inside a typical cell, what are the concentrations of sodium chloride and potassium chloride?
High potassium chloride, low sodium chloride
15 mM Na+ Cl-
150 mM K+ Cl-
Outside a typical cell, what are the concentrations of sodium chloride and potassium chloride?
Low potassium chloride, high sodium chloride
150 mM Na+ Cl-
15 mM K+ Cl-
How can we calculate the voltage across a cell membrane?
Using the Nernst equation
What is the typical resting membrane potential for a cell?
Between - 60 and - 90 mV
