Chapter 9: Lipids and Membranes Flashcards
Draw Palmitic Acid
Should have 16 carbons, saturated. No double Bonds
Draw Oleic Acid
Should have 18 carbons, unsaturated. 1 Double bond at 9th carbon from carboxyllic acid
Draw Linolenic Acid
18 Carbons. 2 Double bonds at 9th and 12th carbon. Omega-6 Fatty Acid
Draw alpha-linoleic Acid
18 Carbons. 3 double bonds at 9th, 12th, and 15th carbon from the carboxyllic acid. Omega-3 fatty acid.
Draw Steric Acid
18 Carbons, saturated. No double bonds
Draw dipalmitylphosphotidylserine
serine is linked to phosphate via its OH group
Draw phosphatidylcholine
choline has 3 methyl groups attached to a positively charged N
Draw phosphatidylserine
serine is linked to phosphate via its OH group
Draw phosphatidylglycerol
glycerol like its own backbone.
Do lipids form polymers?
no, they tend to aggregate and associate together via non-covalent interactions (hydrophobic interactions)
How are fatty acids classified?
by the nature and length of their hydrocarbon chains
What aggregate type do fatty acids form?
micelles- they are amphiphathic because of the COOH and then the non polar R chain
What state is the hydrophillic group of a fatty acid in at physiological ph?
at ph 7.0, the carboxyllic acid is deprotonated
What is the function of a fatty acid?
they serve as intermediates in metabolism and as building blocks for other lipids
do fatty acids play a role in energy storage? Why or why not?
no. their amphipathic nature makes them susceptible to forming micelles due to hydrophobic interactions, thus acting as a soap in the body and dissolving molecules in the body
How would you increase the melting point of a fatty acid?
increase the chain length by increasing the number of carbons. Increase the saturation
How would you decrease the melting point of a fatty acid?
decrease the chain length, and increase the number of double bonds (increase degree of unsaturation). makes the fatty acid more liquidy.
What formation is the an unsaturated lipid in ?
cis
Which unsaturated fatty acid would have a higher melting point? Cis or Trans? Why?
Trans fatty acids have a higher melting point because they can stack more easily than cis fatty acids, allowing them to be solid.
How are fatty acids usually numbered?
starting from the carboxylic acid/carboxylate ion
What’re the two essential fatty acids?
alpha-linolenic fatty acid (w3) and linoleic acid (CLA, w-6)
What type of lipids makes up fats and oils?
triacylglycerols
Difference between fat and oil
fat=solid at room temp
oil=liquid at room temp
What makes up a triacyl glycerol
glycerol and three fatty acid chains held together via ester linkages
what is the suffix of a triacylglycerol?
“oyl”
What is the function of a triacylglycerol? What part of its structure allows it to perform its task?
Energy storage. Unlike fatty acids and other lipids that are polar, the carboylate group on the triacylglycerol is capped with the glycerol head, rendering it non polar and non-amphipathic. Because of its nature, it does not form micelles and can be safely stored in adipose cells without interacting with other portions of the cell.
Further more, since its structure renders it nonpolar, it can be stored anhydrously; unlike carbs and proteins, it can be stored dry, not with water.
Lastly, it provides lots of energy because it holds three long fatty acid chains that are highly reduced (often saturated).
What makes up a glycerophospholipid?
Glycerol+ two free fatty acids+ phosophatidic acid
Are glycerophosphlipids amphipathic? Where would you find one?
they are amphopathic because they have non polar carbon chains and a polar phosphate group that is not capped by the glycerol head. You would find a glycerophospholipid in a membrane.
Which glycerophospholipid does not participate in hydrogen bonding?
glycerophospholipids that contain a phosphtidylcholine chain will not participate in Hbonding because the nitrogen is saturated with carbon.
What makes up a sphingolipid? Where would you find this type of lipid?
ceramide with a head group (varies depending on type of sphingolipid). Membrane lipids, also found in myelin sheath
What is a sphinogmylein lipid
Ceramide+ phosphocholine or phosphoethanolamine. Makes up plasma membrane
Is sphingomyelin ionic or nonionic?
ionic because of it’s phosphate group
On a cerimide, what holds the acyl group?
amide linkage/bond