1.5 Lipids Flashcards
What type of solutions are lipids soluble in
Organic solvents
What are the roles of lipids
Source of energy
Waterproofing
Insulation
Protection
Flexibility in membrane
What are phospholipids
Phospholipids are found in the cell membrane and contribute to the flexibility of it and transfer lipid soluble substances across them
What are triglycerides made up of
Made up 3 fatty acids combined with glycerol
What type of bond is formed between fatty acids and glycerol
They form an ester bond through condensation reaction
How are differences in fats and oils caused
Variation of fatty acids
What does saturated mean
Saturated means there are no C-C double bonds.
Why are triglycerides a good source of energy
This is because they have a high ratio of energy-storing carbon-hydrogen bonds to carbon atoms
Why does triglyceride not affect water potential
This is because they are insoluble in water
Why are triglycerides a important source of water
They have a high ratio of hydrogen to oxygen atoms and therefore release water when oxidised
What is a phospholipid made out of
2 fatty acids and a phosphate
What are the 2 parts that a phospholipid is made out of
Hydrophilic(head
Which is attracted to water but not with fat
Hydrophobic tail which orients away from water but mixes readily with fat
What do phospholipids molecules form
They form a bilayer within cell-surface membrane and as a result a hydrophilic barrier formed between inside and outside of cell
What is the test for lipids
Take dry and grease free test tube
Add 2cm³ of sample, add 5cm³ of ethanol
Shake up the tube to dissolve lipids
Add 5cm³ of water and shake gently
Milky white emulsion indicates presence of lipid
