Membrane Structure And Function Flashcards
What are membranes?
Membranes are phospholipid polymers or fatty acids, glycerol, phosphorus and a terminal amine group.
Membrane phospholipids are amphipathic molecules, what does this mean?
They are both hydrophilic and hydrophobic
Give four functions of cellular membranes
Compartmentalise metabolic activities
Separate/protect cellular components
Provide scaffolding for signalling
A medium for cellular energy generation
Membranes are a barrier to diffusion, true or false?
True
Proteins usually carry an excess of what charge?
Negative
What can diffusion across semi-permeable membranes generate?
A small imbalance in ion concentration
When does a membrane voltage occur?
When immobile charges are not balanced or when charge transport is not fully balanced.
What is diffusion of ions driven by?
Both electrical and chemical gradients
What equation describes the equilibrium between chemical and electrical forces on a charged molecule?
The Nernst equation
How can we measure voltage across cell membranes?
Using microelectrodes implanted in the cells.
How can we measure voltage across other membranes?
Voltage sensitive dyes
What is a cell’s mean diffusion time?
<0.1s
Where are membranes found?
De limiting all organelles in a eukaryotic cell
How are membranes maintained?
Membrane lipid synthesis - vesicles traffic through the Golgi - membrane and cargo delivery/recovery by endocytosis and exocytosis
What does GFP stand for?
Green fluorescent protein
