Lipids and Cell Membranes Flashcards
(32 cards)
What are the three main categories of molecules found in the lipid bilayer?
Glycerophospholipids, sphingolipids, cholesterols
Three things in a glycerophospholipid/phosphoglyceride:
-Glycerol, phosphate, and one or more fatty acids
Two types of fatty acids and what they look like
- Saturated: no double bonds
- Unsaturated: one or more double bonds that has cis config (creates a bend in fatty acid)
How are glycerophospholipids/phosphoglycerides related to fats? How do they differ?
- Both have a glycerol and backbone and two fatty acids.
- They differ in having a phosphate group attached to position #3 of the glycerol
How do you name a glycerophospholipid /phosphoglyceride? Give example
You call it “phosphatidyl-X” where X is the name of the molecule attached to the phosphate. Ex: Phosphotidylserine has serine attached to phosphate.
What is the name of the glycerophospholipid/ phosphoglyceride with no molecule attached to the phosophate? What is this molecule important for?
Phosphotidic acid. It is an important intermediate for the synthesis of phosphatidyl lipids as well as other fats.
What are sphingolipids related to and what are they based off of?
Related to glycerophospholipids and based on sphingosine.
What is sphingomyelin?
A component of the myelin sheath of nerve cells.
Sphingolipids containing single sugars are called:
Sphingolipids containing a complex carbohydrate moiety are called:
- cerebrosides
- gangliosides
Steroids are:
Lipids that are not derived from fatty acids. In animals derived from cholesterol.
Cholesterol is important for:
Makes up how much of the brain?
- Membrane stability. And is prominent part of the brain.
- 14% of dry weight of brain
Fatty acids (single) form what?
Single lipid layer called a Micelle. Also known as soap.
Integral membrane protein:
Difficult to remove from membrane?
protein projects through both sides of the membrane
-Yes
Peripheral membrane protein:
Difficult to remove from membrane?
protein projects into only one side of the membrane. Often associated with integral membrane protein.
-No
Anchored membrane protein:
protein is linked to a molecule embedded in the lipid bilayer, like a fatty acid.
Associated membrane protein:
Difficult to remove from membrane?
protein associates by hydrogen bonding with an integral membrane protein.
-No
What is an integral membrane protein that uses light, chemistry, and mechanics to move protons across a membrane barrier
Bacteriorhodopsin
One can assemble artificial lipid bilayers containing compounds as a means of delivering materials into cells. These artificial systems are called:
Liposomes.
These molecules are associated with numerous physiological phenomena, including uterine contraction. They are also associated with pain.
Prostaglandins
What are prostaglandins made from? (the conversion of this to prostaglandins causes pain) What catalyzes the reaction?
Arachidonic acid in a reaction catalyzed by peripheral membrane protein known as prostaglandin synthase (COX enzyme).
COX enzymes are inhibited by what drugs? Why?
Non-steroidal anti-inflammatory drugs (NSAIDS). aspirin or ibuprofen to get rid of pain.
NSAIDS can cause what? and why?
Some prostaglandins are necessary for synthesis of intestinal tissue, so inhibition of them by aspirin may cause stomach irritation.
Medications like VIOXX and CELEBREX where born and many had to be recalled, due to having a side effect of damaging heart tissue. What were they targeting?
COX-2 enzyme commonly found in joints, thought to cause joint pain.
Fluidity of membrane is related to their composition.
- Shorter and unsaturated fatty acids cause membranes to be:
- Longer and saturated fatty acids cause:
- shorter retains fluidity at lower temperature
- longer is more rigid at lower temperature.
