Lipids (1. LF UK, NT)

They are natural non-polar compounds that are insoluble in water, but are soluble in non-polar solvents.

Importance of lipids[edit | edit source]

they are one of the basic components of food, they serve as a source and reserve of energy (38kJ/g)
structural function - they are part of biomembranes (eg: double layer of phospholipids -> form micelles)
protective function - they cover some organs and thus protect them from shock
thermal insulation
solvents of non-polar vitamins (A, D, E, K)
precursors

Divisions[edit | edit source]

Simple[edit | edit source]

they contain only the lipid part

acylglycerols - are esters of VMK and glycerol (fats and oils)

- triacylglycerols are the most abundant in the human diet

waxes (animal, vegetable)

Bilayer of phospholipids and micelle

Composite[edit | edit source]

obsahují lipidovou a nelipidovou část

they contain a lipid and a non-lipid part
glycoacylglycerols - contain a carbohydrate component

- are part of plant membranes

phosphoacylglycerols - are part of biological membranes and lipoproteins

- their molecule is amphipathic

sphingolipids - their basis is a compound that contains the 18-carbon amino alcohol sphingosine

- they are further divided into sphingomyelins containing ceramide and choline, these include cerebrosides and gangliosides containing carbohydrate and sialic acid - they are amphipathic and are found in the brain and nerves

Derived[edit | edit source]

terpenes
steroids

Glycerol

Higher fatty acids[edit | edit source]

They are the basic component of lipids. They have a high number of C, a high number of non-polar bonds and only one functional group - COOH, which is polar. They are unbranched, have a hydrophobic character and a cis arrangement that is natural in nature and our body can break it down.

Glycerol[edit | edit source]

=propane-1,2,3-triol, glycerin
It is a sweet viscous liquid, infinitely miscible with water.

Source of dietary fat[edit | edit source]

extraction of crude fats and oils, sources

vegetable – pressing, extraction
animal – smelting, extraction

Vegetable fats and oils[edit | edit source]

Refining

slime removal (hydration), vegetable slimes, proteins, their complexes - lecithin
deacidification (neutralization) – acid salts
whitening – carotenoids , chlorophylls
deodorization – tocopherols , sterols

Classification[edit | edit source]

By consistency

oils (liquid)
- drying - linen
- semi-drying - sunflower/soybean
- non-drying - olive
fats (plastic, mushy) – lard
waxes (hard, non-greasy) – beeswax

By structure

fatty acids and their soaps R-[CH2]n-COOH
homolipids (esters of fatty acids with alcohols)
1. monohydric alcohols (waxes)
  - aliphatic (cerides)
    - CH₃-[CH₂]₂₅-OH... ceryl alcohol (beeswax)
    - H₃-[CH₂]₁₅-OH... hexadecan-1-ol, cetyl alcohol (cetaceum)
  - alicyclic (steroids) - esters of sterols (cholesterol), triterpene alcohols
2. dihydric alcohols (glycols), Alkoxylipids: 1-Alkoxypropane-2,3-diols Chimyl alcohol
3. trihydric (glycerol) fats and oils
4. polyhydric alcohols:
  - sugers – glycolipids
    - galactose, galactosides, digalactosides, diacylglycerogalactoside (diacylgalactosylglycerol)
  - sacrose (1–3 MK emulsifiers, 6–8 MK low-energy fats (OLESTRA))
  - sorbitol (sugar alcohols) emulsifiers
heterolipids 0.5–2%
- glycerol , MK, another component
- phospholipids (MK esters)
- lipid sulfates (MK esters)
- sulfolipids
- lipamides (MK amides)
- serinol , ceramides , cerebrosides
complex lipids
- proteolipids ( lipoproteins )
- glycolipids (cerebrosides)
- mucolipids (sialoglycosphingolipids = gangliosides)