fatty acid synthesis

118 Pages·2017·10.85 MB·English

Department of Medical Biochemistry
Semmelweis University
Dr. Beáta Törőcsik
Lipid metabolism
2017. 10. 13.
2017. 10. 19.
2017. 10. 20.
2017. 10. 26.
: not to learn
* : structures to learn

Harper’s Biochemistry 30th ed. Chapter 21-25
Any question regarding the lecture material:
[email protected]
Metabolism of lipids – overview.

Absorption of lipids

Lipoprotein metabolism

Oxidation of fatty acids, ketone bodies

Synthesis of fatty acids.
BIOMEDICAL IMPORTANCE of LIPIDS

(1) relatively insoluble in water
(2) soluble in nonpolar solvents

They are important dietary constituents:
high energy value
essential fatty acids
fat-soluble vitamins (A,D,E,K) and other lipophilic micronutrients
Lipids are transported in the blood combined
with proteins in lipoprotein particles

Fat is stored in adipose tissue,
Nonpolar lipids act as electrical insulators,
allowing rapid propagation of depolarization waves along
myelinated nerves.

Lipid biochemistry is necessary for the understanding
of many important biomedical conditions, including
obesity, diabetes mellitus, and atherosclerosis.
The Cellular Compartments of Common Biological Lipids
Lipidomics: New Tools and Applications, Cell 143, December 10, 2010
Triacylglycerols function as energy reservoirs in animals

melting points are lower
for unsaturated fatty acids
* *
melting points are higher
for longer fatty acids

An oil
A fat
Molecular structures of (A) saturated, (B) monounsaturated,
(C) trans fatty, and (D) polyunsaturated fatty acids
(melting point: 69.6°C)
(melting point: 13.4 °C)
(melting point: 52 °C)
(melting point: -9°C)
Nomenclature for saturated fatty acids.
Nomenclature for number and position of double bonds
in unsaturated fatty acids.
e.g. linoleic acid (ω-3), 18:3n-3 or Δ9, Δ12, Δ15

The term “omega” refers to the position of double bond in relation to
methyl group on the end of the fatty acid.
As an example, omega-3 (ω-3) fatty acids have the last double bond 3
carbons from the terminal methyl group. n —3 is equivalent to ω3.

Oleic acid as an example: n —9 is equivalent to ω9.
Fatty acid classification and nomenclature
*
*
*
or Δ9
* or Δ9, Δ12, Δ15

* or Δ9, Δ12

* or Δ5, Δ8, Δ11,
Δ14
Essential fatty acids:

Linoleate
Linolenate
Double bonds cannot be introduced
beyond the Δ9 position
Essential fatty acid deficience