Topic 1: Resting membrane potential Flashcards
What does potential refer to?
Refers to separation of electrical charge across membrane.
What is having an excitable membrane mean?
Cells capable of generating and conducting AP (nerve and muscle cell)
What is it when a cell with an excitable membrane but not generating impulse?
At rest
What is the distribution of electrical charge in H20?
uneven
Is water covalently (share electron) or noncovalently bonded?
Covalently bonded
Is water polar or nonpolar?
Polar (things are different at each end)
What are atoms/molecules that have net electrical charge known as?
Ions
What bond holds 2 oppositely charged ions?
ionic bond
What are spheres of hydration?
Clouds of water that surround each ion
What are positively and negatively charged ions called, respectively?
Cations and anions
What is the building block of cell membrane?
Phospholipids
Phospholipids are long chains of…?
Non polar carbon atoms, bonded to hydrogen atoms also has polar phosphate group
What is the phospholipid “head”?
Polar group, containing phosphate, that hydrophilic
What is the phospholipid
“tail”?
Nonpolar, containing hydrocarbon that’s hydrophobic.
What’s the thickness of the neuronal membrane, and what faces outwards and inwards?
2 molecules thick. Hydrophilic head outward and hydrophobic tail inward
What is neuronal membrane called?
Phospholipid bilayer
What distinguishes neurons from other cells, in terms of protein?
Type and distribution of protein molecule
What do enzymes do?
Catalyse chemical reactions in neurons
What does the cytoskeleton do?
Give neuron its shape
What makes up proteins?
Assembled from various combinations of 20 amino acids
What are the components of amino acids
Has central carbon atom (alpha carbon) bonded to 4 molecular groups:
-Hydrogen atom
-An amino group (NH3+)
-Carboxyl group (COO-)
-And variable group called R group (R for residue)
How do difference in amino acids arise?
Differences in size and nature of R groups
What synthesizes proteins?
Ribosomes
What is the bond that connects amino acids into a chain? And how is it joined?
Peptide bond, joins amino group of one amino acid to carboxyl group of the next
Whats another name for proteins made up of a single chain of amino acids?
Polypeptides
What is the primary structure?
The sequence of amino acids in the polypeptide
What is the secondary structure?
coiling of the polypeptide, e.g., alpha helix
What is the tertiary structure
3-D folding of a polypeptide
What is quaternary structure?
Different polypeptides bonded together to form a larger protein
What is each of the different polypeptides contributing to a protein with quaternary structure called?
A subunit
Which side of phospholipid faces inwards and outward?
Hydrophobic portion facing inward, hydrophilic ends exposed to watery environment on either side
Typically, how many protein molecules for a functional ion channel?
4-6