LIpids Flashcards
What are triglycerides composed of?
Three fatty acids linked to a glycerol molecule
What is the structure of glycerol?
Three carbon backbone, each carbon bonded to an OH group. The rest of the bonds are occupied by hydrogen?
What group do carboxylic acids have attached?
COOH
What is the difference between saturated and unsaturated fats?
Saturated fats contain no double bonds.
What bond is formed between the fatty acid and glycerol?
Ester bond
What type of reaction is esterification?
Condensation
Why are unsaturated fats oils at room temperature?
The double bonds prevent the chains packing closely together.
What is the difference between a triglyceride and a phospholipid?
There is a phosphate group in the place of a fatty acid
Give an example of a charged group which may be attached to the phosphate
Choline
What does the head of a phospholipid consist of?
The phosphate and choline groups
Why are the head groups the head groups hydrophilic?
Both of the groups are electrically charged. They are attracted to water
Why is the tail of a phospholipid considered hydrophobic?
The fatty acids are uncharged and non-polar, which makes them hydrophobic. They are repelled by water.
Why does the membrane form a bilayer?
The hydrophilic heads stay in contact with the cytosol and the hydrophobic tails stay in the middle of the bilayer, away from the water.
How do the unsaturated fatty acids keep the membrane fluid.
Prevent phospholipids packing closely together.
What structure do steroids have?
They have a four ring structure of 17 carbons.
