Lipids and Membranes Flashcards
What is the structure of a phospholipid?
A polar head group attached to a glycerol backbone by a phosphate group, with X2 fatty acid chains attached to the glycerol backbone also.
What are the X4 common news groups found in phospholipids?
1) choline
2) serine
3) ethanolamine
4) inositol
What is the name of these head groups when part of a phospholipid?
Phosphatidyl…
“…choline”
“…serine”
“…ethanolamine”
“…inositol”
Name a phospholipid which does NOT have a glycerol backbone?
How many fatty acid chains does this molecule have?
What molecule replaces the glycerol?
Sphingomyelin
X1
Sphingosine
From which end are fatty acid numbered C1 from?
From the carboxyl end
From which end are fatty acid chains written from?
The non carboxyl end (the opposite of C1)
Where does cholesterol sit within the lipid bilayer?
Between the phospholipids
Does cholesterol increase or decrease fluidity of lipid membranes?
Decreases
What factors increase the fluidity of lipid membranes?
Short tails fatty acids with kinks (unsaturated)
Which phospholipids usually sit on the outside of the cell membranes?
Phosphatidylcholine and sphingomyeline
Which phospholipids usually sit on the inside of the cell membranes?
Phosphatidylserine and phosphatidylethanolamine
What phospholipid movement causes scrambling via scramblases to initiate apoptosis?
Phosphatidylserine
What types of proteins are:
1) embedded in lipid bi-layers spanning the entire layer
2) anchored to the membrane by covalently bound fatty acids
3) attach to the membrane surface via interactions with the first type of proteins or the head group of a phospholipid
1) integral proteins
2) anchored proteins
3) peripheral proteins
What types of enzymes break phospholipids at various points?
Phospholipases
Where do the following enzymes break the phospholipid molecule:
1) PLD
2) PLC
3) PLA1
4) PLA2
1) between head group and phosphate
2) between glycerol backbone and phosphate
3) cleaves fatty acid 1
4) cleaves fatty acid 2
