Lipids Flashcards
What are lipids NOT?
Polymers
What are the characteristics of lipids?
-contain hydrogen, carbon and oxygen
-insoluble in water
-soluble in organic solvents
What are the main groups of lipids called?
triglycerides and phospholipids
What are the roles of lipids?
-source of energy
-waterproofing
-insulation
-protection
-cell membranes
How are lipids a source of energy?
when oxidised, lipids provides x2 the energy as the same mass of carbohydrate and release valuable water
How do lipids provide waterproofing?
Insoluble in water
How do plants and insects use lipids as waterproofing?
waxy, lipid cuticles that conserve water
How do mammals use lipids as waterproofing?
produce oily secretion from sebaceous glands in skin
How do lipids act as insulation?
fats are slow conductors of heat and when stored below body surface, they help retain body heat
How are lipids used in nerve cells?
In the myelin sheath as an electrical insulation
How do lipids act as production?
fat often stored around delicate organs, e.g kidneys
What state are fats at room temperature?
Solid
What state are oils at room temperature?
Liquid
How do lipids function in the cell membrane?
phospholipids contribute to flexibility and transfer of lipid-soluble substances
What forms a triglyceride?
Three fatty acids and one glycerol molecule
Where do bonds form in a condensation reaction for a triglyceride?
each fatty acid forms an ester bond with glycerol