Lipids

Triglycerides- fats and oilsPhospoglycerides- lecithinSterols- cholesterol

Triglycerides

Neutral fats- triesters of fatty acids and glycerol

Fats- solid at room temperatureOlis- liquid at room temperature

Fatty acidsO

OH

O

OH

Stearinsyra

Linolsyra

Glycerol

Stearic acid

Linoleic acid

Glycerol + 3 fatty acids Triglyceride + water

Trigycerides

+ H2O

Saturated or unsaturated fats/oils?

• Saturated- no double bonds

• Unsaturated- one or more double bonds

• Polyunsaturated- many double bonds

• Cis- or trans-double bonds

Oleic acid Lauric acid

Linoleic acid, -6, Mp -5 ºC

Stearic acid, Mp 70 ºC

O

OH

O

OH

Stearinsyra

Linolsyra

-6 and -3 fatty acids are essential

Linoleic acid, -6, Mp -5 ºC

O

OH

O

OH

Stearinsyra

Linolsyra

-6 and -3 fatty acids are essential

Linolenic acid, -3, Mp -11 ºC

Phosphoglycerides

Cell membrane

Steroids

• Cholesterol, sexual hormones

• Carotenoids – fat-soluble vitamins

Stereoids

Oestradiol Cholesterol Testosterone

Lipid transport in the cells

• Low-density lipoproteins LDL- good

• High-density lipoproteins HDL- bad

Carotenoids

Vitamin A (retinol)

http://www.vitaguide.org/vitamin-a.html

Me = CH3

Lykopen rödred

Carotenoides, forts

Vitamin D

http://www.vitaguide.org/vitamin-d.html

Vitamin E Vitamin K

Analysis of lipids

• Iodine or bromine number

• Addition of I2 or Br2

O

OH

BrOH

O

BrBrBr

Omättad fettsyra, linolsyra

+ Br2

Bromerad fettsyra

Unsaturated fatty acid

Brominated fatty acid

Roles of lipids in the body (+)

• Energy storage

• Insulation and protection of organs

• Structural components of cell membranes-3 poly-unsaturated fatty acids reduce

the risk of heart disease

• poly-unsaturated fats may lower levels of LDL cholesterol

Roles of lipids in the body (-)

• Increased risk of heart disease from elevated levels of LDL cholesterol and trans-fatty acids

• The major source of LDL cholesterol is saturated fats (C12, C14 and C16 fatty acids)

• Obesity