Lipids – Fats and Oils

Lipids – Good Fat / Bad Fat Non polar Derivative hydrocarbons

(mostly C and H with some O) Due to the large number of C-

H bonds, they store more food energy than carbohydrates

They provide insulate bodies, protect plants from water loss, protect and cushion organs, insulate nerve tissue, build cell membranes and store energy for later use

Adipocytes are fat-storing cells – fat people don’t have adipocytes, just bigger ones

Triglycerides One glycerol + three

fatty acids Dehydration synthesis

occurs between each of the 3 hydroxyl functional groups in glycerol and the carboxyl group of the fatty acid

3 water molecules are the byproduct of this ester bond

Triglyceride Synthesis http://www.biotopics.co.uk/as/lipidcondensation.html

Saturated and Unsaturated Triglycerides

Saturated fats are triglycerides with no double bonded carbons

They are solid at room temperature, dominate animal fats and can be synthesized by your body

Unsaturated fats are triglycerides with one or more double bonded carbons

They are liquid at room temperature and dominate vegetable fat such as olive oil

Humans cannot synthesize unsaturated fats – they must come from your diet

Phospholipids A phospholipid has a

glycerol backbone, two fatty acids and a polar phosphate-choline group

Phospholipid Bilayer The polar / non-polar

qualities of phospholipids allow them to spontaneously form membranes in water

They are the principal component of all cell membranes and can be saturated or unsaturated

Steroids

Steroids 4 carbon based ring

structure Non polar Include cholesterol,

vitamin D, testosterone, progesterone, estrogen, cortisone, bile salts

Vitamin D is synthesized from the interaction of UV radiation on subcutaneous cholesterol

Steroids

Pigments, Terpenes and Waxes

These are large, diverse groups that include chlorophyll (a pigment), natural rubber (a terpene) and beeswax (a wax)

They are all non polar and extremely stable – providing structural support and protection

In the case of pigments, they absorb photons of light