Lipids Flashcards
What are the two groups of lipid?
- Triglycerides
- Phospholipids
What are the functions of lipids?
- Providing energy
- Storing energy
- Insulating organisms
- Form membranes
- Create hormones
- Waterproofing
What does a triglyceride consist of?
A glycerol molecule and three fatty acids
How are triglycerides formed?
Triglycerides are formed by the condensation between each of the 3 OH groups on the glycerol and the OH group of each fatty acid chain
What bond forms between glycerol and a fatty acid through a condensation reaction?
An ester bond
How many water molecules are released during formation of a triglyceride?
3
What makes up a fatty acid chain?
A long hydrocarbon chain with a carboxyl group at one end
What does a phospholipid consist of?
A glycerol molecule, two fatty acids and a phosphate group
Hpw dpes the structure & properties of triglycerides link to its function?
High ratio of C-H bonds compared to C atoms - stores a lot of energy
High ratio of H to O atoms - triglycerides can act as a metabolic water source as they release water when oxidised
Large and hydrophobic - they are insoluble in water so they do not affect water potential
Relatively low in mass - a lot can be stored in animals without increasing mass & preventing movement
Are triglycerides polar or non-polar?
Non-polar as they have no charge
How does the structure of phospholipids link to its function?
hydrophilic head - attracts water
hydrophobic tails - repels water
forms bilayers - forms double layers with heads facing outwards and tails inwards; creates a membrane
Are phospholipids polar or non-polar?
Polar as the hydrophilic head has a negative charge
The R - group of a fatty acid may be ________ or __________
saturated or unsaturated
In saturated fatty acids the bonds between the carbon atoms are…
all single bonds
e.g C — C — C — C — C
In unsaturated fatty acids the bonds between the carbon atoms are…
not all single bonds; they contain at least one double bond between the carbons
e.g C — C == C — C == C — C
If a fatty acid in a phospholipid is saturated, what does this mean for the membrane?
It will be less fluid
If a fatty acid in a phospholipid is unsaturated, what does this mean for the membrane?
It will be more fluid
