Lipids And Membrane Stuff Flashcards
Describe the composition of a fatty acid
Unbranched hydrocarbon tail with a carboxyl group at one end
What are the 2 types of fatty acids?
Saturated and Unsaturated
Describe a saturated fat
- all single bonds
- straight
- pack together well
Describe an unsaturated fat
- at least one double bond
- bent shape
- do not pack together well
What are the two carbon-carbon double bond configurations?
Cis and Trans
Which of the double bonds have a stronger kink?
Cis
Describe a cis double bond
Causes a V shape
Describe a trans double bond
Causes a smaller diagonal kink
What does changing cis to trans double bonds do to melting point?
Increase melting temperature
Describe a phospholipid
Hydrophilic head with a phosphate group and two hydrophobic hydrocarbon tails with one having a double bond
Is lipid mobility within each leaflet high or low?
High
Is lipid mobility between leaflets high or low?
Very low
What enzymes flip lipids to the other side of the membrane?
Phospholipid translocator or flipases
What is FRAP?
Fluorescence recovery after photobleaching
What does FRAP show?
Diffusion within the plane (shown by a laser bleaching an area of the cell and then you can see fluorescence return to the area because of diffusion)
What is an integral protein?
Proteins that are embedded in the membrane
What is a peripheral protein?
A protein that lays on the lipid membrane and next to another protein
What is a lipid-anchored protein?
A protein that has lipid tails to latch itself into the membrane
What are the three transmembrane domains?
- single alpha helix
- multiple alpha helices
- beta barrel
What type of residues do protein segments within the biolayer have?
Non polar
What is the fluid mosaic model of cell membranes?
The phospholipid bilayers are in a fluid phase with proteins dispersed throughout with constant motion with lipids and proteins alike (besides those that are anchored)
What is passive transport?
Movement down a gradient
What is osmosis?
Diffusion of water across the membrane
What causes Hypertonic conditions?
Adding too much solute out the cell (causes shriveling)
What causes isotonic conditions?
Having equal solute concentrations in and out of the cell
What causes hypotonic conditions?
Too little solute on the outside, causes cell to lyse
What do channel proteins and carrier proteins do?
Facilitated diffusion (Carrier proteins can be active or passive)
What are uniport, symport, and antiport?
Uniport - sends stuff one way
symport - sends things the same way
Antiport - sends stuff opposite ways
Does active transport move things up or down a electrochem gradient?
Up
What is direct active transport?
Straight up pumping something in or out
What is indirect active transport?
Think the proton pump im the ETC, using an active transport created gradient to ride something else in
What does the sodium potassium pump use?
Direct active transport (pumps 3 Na+ out, pumps 2 K+ in)
What does the sodium glucose symport ear use?
Indirect active transport (sodium is brought in with the echem gradient to pump in glucose)
