Membranes Flashcards
What bond holds phospholipids?
Ester bonds
What is the composition of a phospholipid?
Glycerol attached to 2 fatty acid tails and a phosphate head group (with another head group attached).
Adding double bonds to a fatty acid does what?
Makes the bilayer more fluid.
Sphingolipid
Sphingosine instead of glycerol, no phosphate.
Glycolipid
Has sugar as a head group instead of phosphate.
What phospholipid is negatively charged?
Phosphatidylserine.
Cholesterol
Makes lipid bilayer more fluid by filling gaps between the fatty acid tails.
How do hydrocarbon tails interact?
Through van der waals interactions.
What is on the outside of blood cell membranes?
Choline head groups.
What is on the inside of blood cell membranes?
Negative charges.
Cell surface receptors
Transmembrane proteins that bind to signal molecules in the extracellular space.
How do transmembrane proteins cross the lipid bilayer?
In an alpha helix composed of amino acids with nonpolar residues.
Why do peptide bonds form H bonds with each other in the membrane?
Because they are polar.
Where are beta barrels common?
In the outer membranes of bacteria, mitochondria and chloroplasts.
Inside of cell =
Reducing environment, hydrogen tends to get added to things.
