Lipids Flashcards
What type (complex or simple) of lipid are phospholipids?
Complex
What type (complex or simple) of lipids are cholesterol/prostacyclin?
Simple
What are complex lipids made up of?
Other smaller compounds put together
What is the major part of complex lipids?
Fatty acids
What is the shortest hydrocarbon chain length of a fatty acid?
6
What type of double bonds are most double bonds in fatty acids?
Cis
How is the branching of fatty acids?
Can be branched or unbranched
What is a saturated fatty acid?
No C=C
What is an unsaturated fatty acid?
At least one C=C
What is the pKa of a carboxyl group?
4.5
What type of membrane-found lipid can plants not make?
Cholesterol
What is the most common fatty acid?
Palmitate
How many long is the carbon chain in palmitate?
16
Shorthand naming system for fatty acids?
Cx:y delta a, b, c
x=# of carbons
y=# of C=C
a,b,c = positions of double bonds
What two characteristics of a fatty acid can affect the melting point?
Saturation and chain length
What type of lipid (complex/simple) is triacylglycerol?
Complex
What are the four major components of a triacylglycerol?
Three FAs and a glycerol molecule
What is the main storage form of lipid in many organisms?
Triacylglycerols
What characteristic do triacylglycerols that are considered fats have?
Mainly saturated
What characteristic do triacylglycerols that are considered oils have?
Lots of unsaturation
What are the four major components of a phospholipid?
Two FAS, a glycerol and a phosphate group
Why are phospholipids amphipathic?
They have a hydrophilic region and a hydrophobic region
Which part of a phospholipid is hydrophilic?
The polar ionised head–> phosphate group
Which part of a phospholipid is hydrophobic?
The FA
What has an effect on the extent of inter-chain interaction?
Chain length
How does having a longer chain affect inter chain interaction?
Longer chain = more interaction
How does having a higher proportion of long chain fatty acids benefit organisms when it gets warmer?
Longer chain fatty acids allow membranes to stay together at higher temperatures–> prevents membrane from melting
What can organisms that live at different temperatures do to their fatty acids in the plasma membrane?
Modify their chain length
Introducing double bonds
What environmental condition can affect the composition of the fatty acids in the lipids in the phospholipid bilayer?
Temperature
What makes triacylglycerols better storage molecules than carbohydrates?
They dont need water (which takes up space) while carbs do
What do amphipathic molecules form when mixed with water?
Monolayers
What structures can be formed via the agitation of monolayers?
Double membrane capsules or vesicles
How can micelles be produced from amphipathic molecuels?
Vigorous shaking
Why does shaking of amphipathic molecules lead to the formation of micelles?
The close packing of hydrocarbon tails excludes water–> leads to an increase in entropy
Palmitate systematic name?
n-hexadecanoic acid (hexadecanoate)
Which temp does a higher % of long chain FAs do better in?
Higher
Which temp does a lower% of long chain FAs do better in?
Lower
Which temp does a higher % of unsaturated FAs do better in?
Lower
Which temp does a lower% of unsaturated FAs do better in?
HIgher
