Membrane structure and function Flashcards
What are atoms?
The smallest particles that retain the properties of an element
What are atoms made of?
Sub-atomic particles; protons, neutrons and electrons.
What are atoms determined by?
Atomic number
What determines chemical bonding?
An atoms complement if electronic charge (e-) and their distribution
Where do electrons distribute?
Around the atomic nucleus in spaces described as ‘shells’ and ‘orbitals’ which define the probability distribution of an electron
When do ionic bonds arise?
When atoms exchange electrons
When do covalent bonds arise?
When atoms share electrons
What are the most stable atomic states?
Paired electrons and filled electron shells
What is bond capacity also known as?
Atomic valence
What is compound structure determined by?
Valence shells in the bonds
What do hydrogen bonds have?
A partial charge interactions between polar molecules
Where do Van Der Waals interactions arise?
From locally induced dipoles between atoms in very close proximity
What is water?
Polar molecule that forms hydrogen bonds
What does the polarity of water allow?
Solvation interactions with charged (ionic) compounds, solvation interactions with uncharged polar compounds, and high reactivity with many other transition metals
What are membranes?
Phospholipid polymers made up of fatty acids, glycerol, phosphate and a terminal amine
What are membrane phospholipids?
Amphipathic molecules that in water spontaneously form monolayers and bilayers
Function of membranes?
Compartmentalise metabolic activities, separate/protect cellular components, provide a ‘scaffold’ for signalling, and acts as a medium for cellular energy generation
What arises from the immiscibility of water and membranes?
Compartmentalisation, protection and energy generation
What drives the diffusion of ions?
Both chemical and electrical gradients
What generates a small ion imbalance?
Selective diffusion across semi-permeable membranes
What does the Nernst Equation describe?
The equilibrium between chemical and electrical forces on a charged molecule (ion)
A process of bioenergetics
Ion gradients across membranes are used to generate biological energy
What can microelectrodes implanted in cells measure?
The voltage across the cell membrane
