Biological Molecules: Lipids Flashcards
Key features of lipids
- Often referred to as fats
- A diverse group of hydrophobic biological molecules
- Insoluble in water but soluble in inorganic (non-polar) solvents
Saturated fatty acids - single or double bonds?
The hydrocarbon chain has only single bonds between carbons
Why are triglycerides not classed as polymers?
There is only one glycerol molecule in each triglyceride and the fatty acids are not identical or repeating units
Triglyceride composition
Glycerol —> a small 3-carbon molecule with three alcohol (OH) groups
Fatty Acids —> all fatty acids have a carboxylic group and a variable R group
Lipid function (in the plasma membrane)
Contribute to flexibility of membranes and transfer of lipid-soluble substances across them
Unsaturated fatty acids - single or double bond?
The hydrocarbon chain consists of at least one double bond between carbons
Lipid function (in waterproofing)
Waxy cuticles in plants and insects, mammals produce oily secretion
Lipid function (as an energy source)
Lipids are a concentrated energy source
Lipid function (in protection)
Lipids can be used as a form of protection for delicate organs e.g. the kidney
Phospholipid composition
A molecule comprised of 1 glycerol, 1 phosphate group and two fatty acid tails
Lipid function (in insulation)
Helps to retain heat when stored under skin
What is the bond within lipids (between fatty acids and glycerol?)
Ester bonds
