Presentation Lipids Michaela Barošová, Lukáš Malina

Properties of Lipids The Lipids are esters of long chain fatty acids and alcohols (glycerol). They are a large and diverse group of naturally occuring organic compounds that are  generally insoluble in water – they are hydrophobic  soluble in nonpolar solvents such as ether, chloroform, aceton etc. There is a great structural variety among the lipids. diverse - různorodý occuring – vyskytující se

Functions of Lipids 1. store and source of energy for animals and people 2. solvent (for the lipid soluble vitamins such as A, D, E, K) 3. structural components of biological membranes 4. protective function – they protect some organs in human body (kidneys) 5. both lipids and lipid derivatives serve as vitamins and hormones store – rezerva, zásoba protective - ochranný source – zdroj serve - sloužit

Classification of Lipids 1. Homolipids Fatty acids and their derivatives Fatty acids and their derivatives Triacylglycerols Triacylglycerols Wax esters Wax esters 2. Heterolipids Phospholipids Phospholipids Sphingolipids Sphingolipids wax - vosk

Fatty Acids their name mostly reflect their sources their name mostly reflect their sources natural fatty acids may be saturated or unsaturated natural fatty acids may be saturated or unsaturated linoleic and linolenic fatty acids are essential - their absence in the human diet is connected with health problems (increased dehydration ) linoleic and linolenic fatty acids are essential - their absence in the human diet is connected with health problems (increased dehydration ) reflect – odrážet saturated - nasycený SaturatedUnsaturated Common name lauric acid palmitoleic acid myristic acid oleic acid palmitic acid linoleic acid stearic acid linolenic acid arachidic acid arachidonic acid

Triacylglycerols the triesters of fatty acids with glycerol (1,2,3- trihydroxypropane) - CH 2 OHCHOHCH 2 OH the triesters of fatty acids with glycerol (1,2,3- trihydroxypropane) - CH 2 OHCHOHCH 2 OH are contained both in plants and animals are contained both in plants and animals represent one of the major food group of our diet represent one of the major food group of our diet solid at room temperature are classified as fats (occur mainly in animals) solid at room temperature are classified as fats (occur mainly in animals) liquid are called oils (mainly in plants, but triacylglycerols from fish are also oils) liquid are called oils (mainly in plants, but triacylglycerols from fish are also oils)

Triacylglycerols - continued fats have a predominance of saturated fatty acids fats have a predominance of saturated fatty acids oils are composed largely of unsaturated acids oils are composed largely of unsaturated acids herring – sleďový corn – obilí peanut – burský oříšek Animal fats Plant oils buttercoconut human fat corn herring oil olive soyabean peanut

Reactions of Triacylglycerols the acid-catalyzed hydrolysis is used for production of candles: the acid-catalyzed hydrolysis is used for production of candles: CH 2 –O–COR 1 CH 2 –OH R 1 –COOH CH 2 –O–COR 1 CH 2 –OH R 1 –COOH │ │ │ │ CH–O–COR 2 + 3H 2 O  CH–OH + R 2 –COOH CH–O–COR 2 + 3H 2 O  CH–OH + R 2 –COOH │ │ │ │ CH 2 –O–COR 3 CH 2 –OH R 3 –COOH CH 2 –O–COR 3 CH 2 –OH R 3 –COOH

Reactions of Triacylglycerols - continued the base-catalyzed hydrolysis (saponification) is used for production of soaps the base-catalyzed hydrolysis (saponification) is used for production of soaps potassium soaps are soft and were then converted to the harder sodium soaps by washing with salt solution potassium soaps are soft and were then converted to the harder sodium soaps by washing with salt solution CH 2 –O–COR 1 CH 2 –OH R 1 –COONa │ │ │ │ CH–O–COR 2 + 3NaOH  CH–OH + R 2 –COONa CH–O–COR 2 + 3NaOH  CH–OH + R 2 –COONa │ │ │ │ CH 2 –O–COR 3 CH 2 –OH R 3 –COONa CH 2 –O–COR 3 CH 2 –OH R 3 –COONa

Waxes are esters of fatty acids with long chain monohydric alcohols (one hydroxyl group) are esters of fatty acids with long chain monohydric alcohols (one hydroxyl group) waxes are widely distributed in nature waxes are widely distributed in nature the leaves and fruits of many plants have waxy coatings – protect them from dehydration and small predators the leaves and fruits of many plants have waxy coatings – protect them from dehydration and small predators examples: spermaceti: CH 3 (CH 2 ) 14 CO 2 -(CH 2 ) 15 CH 3 examples: spermaceti: CH 3 (CH 2 ) 14 CO 2 -(CH 2 ) 15 CH 3 beeswax: CH 3 (CH 2 ) 24 CO 2 -(CH 2 ) 29 CH 3 beeswax: CH 3 (CH 2 ) 24 CO 2 -(CH 2 ) 29 CH 3

Phospholipids structural components of biomembranes structural components of biomembranes hydrophobic domain: composed largely of fatty acids hydrophobic domain: composed largely of fatty acids hydrophilic domain: containes phosphate or other polar groups hydrophilic domain: containes phosphate or other polar groups Sphingolipids Sphingolipids important components of animal and plant membranes important components of animal and plant membranes contain long – chain amino alcohol, in animals sphingosine contain long – chain amino alcohol, in animals sphingosine compose – skládat se beeswax – včelí vosk sparmaceti - vorvaňovina

References Thank you for your attention