Flashcards in B M 2 : Lipids Deck (24):
what are triglycerides made of
- one molecule of glycerol
- 3 fatty acids attached to it
fatty acids tails made of?
- fatty acids have long tails made of hydrocarbons
- tails are hydrophobic
- tails make lipids insoluble in water
all fatty acids have same basic structure, what is it?
C= carbon atom links fatty acid to glycerol
R= variable R group hydrocarbon tail
whats one thing that varies in the different fatty acids?
what reaction forms triglycerides?
what bond forms between a fatty acid joining to a glycerol molecule?
what is released when an ester bond is formed?
A water molecule (as it's a condensation reaction)
how many times does a glycerol molecule join to a fatty acid to produce a triglyceride?
what are the two types of fatty acid?
Saturated or unsaturated
what causes the difference between saturated and unsaturated?
The hydrocarbon tails (R group)
structure of saturated fatty acids?
- Don't have any double bonds between their carbon atoms
- fatty acid is saturated with hydrogen
structure of unsaturated fatty acids?
- have at least one double bond between carbon atoms
- causes chain to kink
what are the lipids found in cell membranes?
whats the difference between phospholipids an triglycerides?
- similar except one fatty acid molecule is replaced with a phosphate group
which parts of phospholipids are hydrophobic and hydrophilic
hydrophobic = fatty acid tails
hydrophilic = phosphate group
what does the structure of lipids relate to?
what are triglycerides mainly used as?
energy storage molecules
1 reason why triglycerides are good as energy storage molecules?
- long hydrocarbon tails of fatty acids contain lots of chemical energy when they're broken down
- because of this lipids contain twice as much energy per gram as carbhydrates
another reason why triglycerides are good as energy storage molecules?
- insoluble, so don't affect water potential of the cell and cause water to enter the cell by osmosis
- triglycerides clump together as insoluble droplets in cells because fatty acid tails are hydrophobic = tails face inwards. shielding themselves from water with their glycerol heads
what do phospholipids make up?
the bilayer of cell membranes
1 reason why phospholipids are good as a bilayer?
- heads hydrophilic and tails hydrophobic, so form a double layer with their heads facing out towards the water on either side
another reason why phospholipids are good as a bilayer?
center of bilayer is hydrophobic, so water-soluble substances can't easily pass through it - membrane acts as a barrier to those substances
what test can test for lipids?