2. Fatty Acids Fatty acids have a long hydrocarbon chain with a carboxyl (acid) group Typical for of fatty acids : CH 3 –(CH 2 ) n –COOH 12<n<20

3. Saturated- Unsaturated Fatty Acids

4. Hydrophobic- Hydrophilic Groups The hydrocarbon tail is extremely hydrophobic and so is insoluble in water. In contrast, the carboxylic acid group is extremely hydrophilic.

5. Common Fatty Acids Common name Chemical structure Myristoleic acid CH 3 (CH 2 ) 3 CH=CH(CH 2 ) 7 COOH Palmitoleic acid CH 3 (CH 2 ) 5 CH=CH(CH 2 ) 7 COOH Oleic acid CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 7 COOH Linoleic acid CH 3 (CH 2 ) 4 CH=CHCH 2 CH=CH(CH 2 ) 7 COOH α-Linolenic acid CH 3 CH 2 CH=CHCH 2 CH=CHCH 2 CH=CH(CH 2 ) 7 COOH Arachidonic acid CH 3 (CH 2 ) 4 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CH(CH 2 ) 3 COOH Eicosapentaenoic acid CH 3 CH 2 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CH(CH 2 ) 3 COOH Erucic acid CH 3 (CH 2 ) 7 CH=CH(CH 2 ) 11 COOH Docosahexaenoic acid CH 3 CH 2 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CHCH 2 CH=CH(CH 2 ) 2 COOH

6. Common Fatty Acids

7. Fats  FAT consists of three- carbon backbone called glycerol attached to three fatty acids, which contain long hydrocarbon chains.

8. Ester Bond Formation

9. Phosphoglycerids Phospholglycerides are esters of only two fatty acids, phosphoric acid and a trifunctional alcohol - glycerol (IUPAC name is 1,2,3-propantriol). The fatty acids are attached to the glycerol at the 1 and 2 positions on glycerol through ester bonds.

10. Phospholipids Phospholipids have a structure like a triglyceride,but contain a phosphate group in place of the third fatty acid. The phosphate group is polar and therefore capable of interacting with water molecules.

11. STEROIDS Steroids have a backbone of 4 carbon rings. Cholesterol is the precursor of several other steroids, including several hormones. It is also an important component of cell membranes.

13. REFERENCES Michael L. Shuler and Fikret Kargı, Bioprocess Engineering: Basic Concepts (2 nd Edition),Prentice Hall, New York, 2002. 1. James E. Bailey and David F. Ollis, Biochemical Engineering Fundementals (2 nd Edition), McGraw-Hill, New York, 1986.

14. hyperphysics.phy-astr.gsu.edu www.chemistryland.com virtuallaboratory.net http://www.ific.org/publications/reviews/imag es/irfatschart_2.gif io.uwinnipeg.ca bioweb.wku.edu http://www.wisc- online.com/objects/index_tj.asp?objid=AP13 204