TABLE OF CONTENTS

TITLE PAGE                  –         –         –         –         –         –         –         i

CERTIFICATION           –         –         –         –         –         –         –         ii

DEDICATION      –         –         –         –         –         –         –         –         iii

ACKNOWLEDGMENT            –         –         –         –         –         –         iv

TABLE OF CONTENTS          –         –         –         –         –         –         v-viii

CHAPTER ONE: INTRODUCTION

1.1     Background of the study            –         –         –         –         –         1-6

CHAPTER TWO

2.0   FATTY ACID       –         –         –         –         –         –         –         7-8

2.1     Classes of Fatty Acids     –         –         –         –         –         –         8-10

2.2     Major Classes Fatty Acid –         –         –         –         –         –         10

2.2.1  Oleic Acid   –         –         –         –         –         –         –         –         10

2.2.2  Linoleic Acids       –         –         –         –         –         –         –         11

2.3     Properties of Fatty Acids           –         –         –         –         –         11-15

2.4     Synthesis of Fatty Acids  –         –         –         –         –         –         15-17

2.5     Mechanism of Action of Fatty Acids   –         –         –         –         17

2.5.1  Eicosanoids           –         –         –         –         –         –         –         17-18

2.5.2  Substrate Specificity        –         –         –         –         –         –         18

2.5.3  Membrane Fluidity          –         –         –         –         –         –         18-19

2.5.4  Lipid Peroxidation –         –         –         –         –         –         –         19-20

2.5.5  Acylation of Protein        –         –         –         –         –         –         20-21

CHAPTER THREE

3.0 OMEGA -3 FATTY ACIDS AND OMEGA -6 FATTY ACID        –         –         –         –         –         22-23

3.1     Types of Omega-3  Fatty Acids           –         –         –         24

3.1.1  Eicosanoids Acids (EPA)          –         –         –         –         24-25

3.1.2  Docohexaenoic (DHA)    –         –         –         –         –         25-26

3.1.3  Alpha-Linolenoic  Acids (ALA)          –         –         –         26-27

3.2     The Role of Omega 3 and 6 Fatty Acids in Health             27-30

3.3     Food Sources of Omega 3 and 6 Fatty Acids           –         30-32

3.4     Omega 6 Fatty Acids       –         –         –         –         –         32-35

3.5     Health Effect of Omega 3 Fatty Acids and

Omega 6 Fatty Acids       –         –         –         –         –         35-36

3.6     Biochemical Role of Omega 3 and Omega 6 Fatty Acid    36-38

CHAPTER FOUR: SUMMARY AND CONCLUSION

4.1     Summary     –         –         –         –         –         –         –         39-42

4.2     Conclusion  –         –         –         –         –         –         –         32-43

References

CHAPTER ONE

1.0     INTRODUCTION

Fatty acids are a class of aliphatic monocarboxylic acids that form part of a lipid molecule and can be derived from fat by hydrolysis ; fatty  acids are  simple molecules built around a series of carbon atoms linked together in a chain of 12 to 22 carbon atoms (Chaiyasit et al., 2007)

Fatty acids, both free and as part of complex lipids, play a number of key roles in metabolism of major metabolic fuels (storage and transport of energy), as essential components of all membranes, and as gene regulators. As part of complex lipids, fatty acids are also important for thermal and electrical insulators and for mechanical protection.

The two major classes of polyunsaturated fatty acids (PUFAs) are the Omega-3 and Omega-6 fatty acids. Like all fatty acids, polyunsaturated fatty acids consist of long chains of carbons atoms with a carboxyl group at one end of the chain and a methyl group at the other (Chaiyasit et al., 2007).

Omega-3 fatty acids (omega-3s) have a carbon-carbon double bond located three carbon from the methyl end of the chain. Omega-3s, sometimes referred to as ‟n-3s”, sometimes are presents in certain foods such as flaxseed and fish, as well as dietary supplements such as fish oil (Scorletti and byrne, 2013).

Omega-3 fatty acids are polyunsaturated fats, a type of fats the body cannot make. The term ‟polyunsaturated” refers to their chemical structure, as ‟poly” means many and ‟unsaturated” refers to double bonds. Together they mean that omega-fatty acids have many double bonds, ‟ omega-3” refers to the position of the double bond in the chemical structure, which is three carbon atoms from the ‟omega” or tail end of the molecular chain. Since the human body cannot produce omega-3s these fats are referred to as ‟essential fats”, meaning that we have to get them from our diet. Omega-3s play important roles in the body as components of the phospholipids that form the structures of cell membranes (Wang et al., 2006). DHA, in particular, is especially high in the retina, brain and sperm. In addition to their structural role in cell membranes, omega-3s (along with omega-6s) provide energy for the body and are used to form eicosanoids. Eicosanoids are signaling molecules that have similar chemical structures to the fatty acids from which they are derived; they have wide-ranging functions in the body’s cardiovascular, pulmonary, immune and endocrine system (Cooper et al., 2016).

The eicosanoids made from omega-6s are generally more potent mediators of inflammation, vasoconstriction and platelet aggregation than those made from omega-3s although there are some exceptions. Because both classes of fatty acids compete for the same desaturation enzymes,   α-lenolenic acid (ALA) is a competitive inhibitor of linoleic acid metabolism and vice versa.

Similarly, eicosapentanoic (EPA) and Docosahexaenoic (DHA) can compete with arachidonic acids for the synthesis of eicosanoids. Thus, higher concentrations of eicosapentanoic acid (EPA) and docohaxaenoic (DHA) than arachidonic acids tip the eicosanoids balance towards less inflammatory activity. (Freund et al., 2006). Some researchers propose that the relative intakes of omega-6s  and omega-3s. The omega-3s and omega-6s ratio may have important implications for the pathogenesis of many chronic disease and cancer, but the optimal ratio of any has not been defines. (Lee et al., 2012).

Omega-6 fatty acids are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond, counting from the methyl end (Aung et al., 2018).  Members of the family can have pro-inflammatory or anti-inflammatory effect. Omega-6 fatty acids are composed of polyunsaturated fatty acids in which the first double bond in the hydrocarbon chain occurs between the site and seventh carbon atoms from the end of the molecules most distant from the carboxylic acids group and which are found especially in vegetables oils, nut, beans, seeds and grains.

Structures of omega-6 and omega-3 fatty acids

Omega-3 fatty acids differ from omega-6 fatty acids by the location of their first double bond from the methyl (CH 3 ) end of the fatty acid. Omega-3 fatty acids include a-linolenic acid (ALA), eicosapentanoic acid (EPA), and docosahexanoic acid (DHA). Omega-6 fatty acids include linoleic acid (LA), arachidonic acid (AA), and docosapentanoic acid (DPA). In the chemical names, the number of carbon atoms is given first, separated by a colon from the number of double bonds, followed by the position of the first double bond.