Pharos university Faculty of Allied Medical SCIENCE Biochemistry 1 (MLBC-201)

1. Pharos universityFaculty of Allied Medical SCIENCEBiochemistry 1(MLBC-201) Dr. Hewaida Fadel Dr. Tarek El Sewedy Department of Medical Laboratory Technology Faculty of Allied Medical Sciences

2. Lecture Lipids and Fatty acids (2)

3. Intended Learning Outcomes • By the end of this lecture, students will learn: • How to write the chemical formula of fatty acids. • Classification of fatty acids. • Lipid Nutritional facts.

4. Lecture Content • Classification of lipids. • Nomenclature of fatty acids. • Classification of fatty acids. • Fats and diet

5. Fatty Acids Fatty acids are hydrocarbon chains of various lengths and degrees of unsaturation that terminate with carboxylic acid groups. a. Stearic acid (saturated) B. Oleic Acid (unsaturated)

6. 1. Classification of lipids • Simple • Complex • Precursor or Derived

7. Lipids in Cell Membrane (Phospholipds) 1 glycerol + 2 fatty acids + 1 phosphate group + 1 organic functional group = phospholipid Phosphate groups – Interacts with water; because the phosphate head is polar. Fatty acid ‘legs’ – Non-polar, do not interact with water and align themselves together to be protected from the water while exposing the phosphate groups to the water.

8. C. Derived lipids • These include lipid-soluble vitamins, and hormones.

9. Nomenclature of Fatty Acids • The name for a fatty acid is derived from the name of its parent hydrocarbon by the substitution of oicfor the final e. ex. the C18fatty acid is called octadecanoicacid because the parent hydrocarbon is octadecane (18) • The notation 18:0denotes a C18 fatty acid with no double bonds, whereas (18:3n 9,12,15) signifies that there are three double bonds at position 9,12 and 15 of carboxyl carbon. • Carbon atoms are numbered from the carboxyl carbon (carbon No. 1). The carbon atoms adjacent to the carboxyl carbon (Nos. 2, 3, and 4) are also known as the α, β, and γ carbons, respectively, and the terminal methyl carbon is known as the ω or n-carbon

11. I-According to number of carbon atoms Short chain long chain 2-10 C atoms>10 C atoms Butyric acid (4 C) Palmitic acid(16C)

12. II-According to presence or absence of double bond Saturated unsaturated MonounsaturatedPolyunsaturated Palmitic acid, Butyric acid, Caproic acid, Stearic acid Linoleic acid C18 Linolenic acid C18 Arachidonic acid C20 Oleic acid C18 Nervonic acid C24

15. Common Unsaturated Fatty Acids

16. Unsaturated fatty acid are classified into Cis trans • Cis and trans are terms that refer to the arrangement of the two hydrogen atoms bonded to the carbon atoms involved in a double bond. In the cis arrangement, the hydrogens are on the same side of the double bond. In the trans arrangement, the hydrogens are on opposite sides of the double bond

17. III-According to nutrition state EssentialNon essential Sarurated FA Monounsaturated FA Polyunsaturated Linoleic acid C18 Arachidonic acid C20

18. 1-Non essential fatty acids: They can be synthesized in the human body All saturated and monounsaturated FA's Ex: Palmitoleic acid ( 16:1n;∆9) CH3(CH2)5CH=CH(CH2)7COOH higher concentrations in the liver Ex: Oleic acid; ( 18:1n;∆9) majority of olive oil

19. 2- Essential fatty acids Polyunsaturated fatty acids Need to get them from diet because the body cannot manufacture them. Alpha linolenic acid (18:3n;∆9,12,15): is the so-called "parent" fatty acid for the omega 3 family of fatty acids because the liver can make other omega 3 fatty acids from it.

20. linoleic acid (LA)(18:2n; ∆9,12); Is the "parent" fatty acid for the synthesis of other omega 6 fatty acids in the liver.  It is found in the lipids of cell membrane. It is abundant in many vegetable oils, and sunflower oils.

21. Arachidonic acid (20;4n;5,8,11,14) Repair and Growth of skeletal muscle tissue Abundant fatty acids in the brain Play a central role in inflammation

22. Omega-3 fatty acids • Omega-3 fatty acids (also known as n-3 fatty acids) are polyunsaturated fatty acids that are essential nutrients for health. We need omega-3 fatty acids for numerous normal body functions, such as controlling blood clotting and building cell membranes in the brain, protection against heart disease . • Our bodies cannot make omega-3 fats, we must get them through food. • Alpha-linolenicacid (ALA) is the parent compound for Omega 3 fatty acid, is found in some vegetable oils such as soybean, canola, and in walnuts.

23. Omega-3 fatty acids • For good health, we should aim to get at least one rich source of omega-3 fatty acids in our diet every day. This could be through a serving of fatty fish (such as salmon), a tablespoon of canola or soybean oil in salad dressing or in cooking, or a handful of walnuts.

24. Omega-6 fatty acids • Omega-6 fatty acids (also known as n-6 fatty acids) are also polyunsaturated fatty acids that are essential nutrients, meaning that our bodies cannot make them and we must obtain them from food. • Common dietary sources include safflower, corn, cottonseed, and soybean oils. • Omega-6 fatty acids lower LDL cholesterol (the "bad" cholesterol) and reduce inflammation, and they are protective against heart disease. So both omega-6 and omega-3 fatty acids are healthy.

26. Cis and Trans Lipids • Naturally-occurring unsaturated vegetable oils have almost all cis bonds, but reusing oil for frying causes some of the cis bonds to convert to trans bonds. • If oil is used only once like when you fry an egg, only a few of the bonds do this so it’s not too bad. However, if oil is constantly reused, like in fast food French fry machines, more and more of the cis bonds are changed to trans until significant numbers of fatty acids with trans bonds build up. • Studies showed that fatty acids with trans bonds are carcinogenic and leads to significant increase inheart disease by increasing levels of bad cholesterol (LDL). The levels of trans fatty acids in highly-processed (hydrogenated oils), lipid-containing products such as margarine are quite high.

27. Cholesterol • Cholesterol is a waxy substance your body uses to protect nerves, make cell tissues and produce certain hormones. •  A little cholesterol is essential for health. • The liver can manufacture all the cholesterol your body needs. • Low-density lipoprotein (LDL or 'bad') cholesterol can join with fats and other substances to build up in the inner walls of your arteries. The arteries can become clogged and narrow, and blood flow is reduced. High-density lipoprotein (HDL or 'good') carries harmful cholesterol away from the arteries and helps protect you from atherosclerosis, heart attack and stroke.

28. Atherosclerosis A type of arteriosclerosis. Atherosclerosis causes arteries to narrow, weaken and be less flexible. It's the term for the process of fatty build-up in the inner lining of an artery. The build-up that results is called plaque and reduces the amount of blood and oxygen that is delivered to vital organs.

30. Triglycerides Triglyceride is a form of fat made in the body. Elevated triglycerides can be due to overweight/obesity, physical inactivity, cigarette smoking, excess alcohol consumption and a diet very high in carbohydrates. People with high triglycerides often have a high total cholesterol level, including a high LDL (bad) level and a low HDL (good) level. Many people with heart disease and/or diabetes also have high triglyceride levels.

31. Fats and diet Eating low fat food doesn’t mean we should give up fat entirely, but we do need to educate ourselves about which fats should ideally be avoided and which ones are more heart-healthy. We need fat in our diet. As the most concentrated source of calories (nine calories per gram of fat compared with four calories per gram for protein and carbohydrates), it helps supply energy. Fat provides linoleic acid, an essential fatty acid for growth, healthy skin and metabolism. It also helps absorb fat-soluble vitamins (A,D,E and K). And fat adds flavourand is satisfying, making us feel fuller Although all fats have the same amount of calories, some are more harmful than others: saturated fats and trans fats in particular.

32. Saturated fats • These fats are derived from animal products such as meat, dairy and eggs. But they are also found in some plant-based sources such as coconut, palm oils. These fats are solid at room temperature. Saturated fats directly raise total and LDL (bad) cholesterol levels. Conventional advice says to Avoid them as much as possible A meta-analysis published in 2003 found a direct relationship between saturated fat and breast cancer. In 2007, a systematic literature review published by the World Cancer Research Fund and the American Institute for Cancer Research found consistent evidence for a direct relationship between animal fat and colorectal cancer. 

33. The Ugly fats Trans Fats or Hydrogenated Fats Trans Fats are typically found in packaged goods and fast food restaurants They all have/use the ugly fats… TRANS FATS!

34. The Ugly fat  scientists discovered that they could createa fat that would prolong the spoiling of packaged goods by simply adding a hydrogen atom to an unsaturated fat. The partially hydrogenated fat creations wouldn’t spoil as easily as non-hydrogenated fats, plus they didn’t break down during temperature changes, which made transporting them easier, and they were less expensive than animal fat. Another ugly man-made invention!

35. Trans Fats or Hydrogenated Fats Are actually unsaturated fats, but they can raise total and LDL (bad) cholesterol levels while also lowering HDL (good) cholesterol levels. Trans fats are used to extend the shelf life of processed foods, typically cookies, cakes, fries and donuts. Any item that contains “hydrogenated oil” or “partially hydrogenated oil” likely contains trans fats. Hydrogenation is the chemical process that changes liquid oils into solid fats. Since January 2006, all food manufacturers are required to list trans fat content on food labels.

36. Butter Margarine, tub Margarine, stick 

37. Unsaturated fats • Monounsaturated fats and polyunsaturated fats are two types of unsaturated fatty acids. They are derived from vegetables and plants. • Monounsaturated fats: • This type of fat is preferable to other types of fat and can be found in olives, olive oil, nuts, peanut oil, canola oil and avocados. These kinds of fats can lower LDL (bad) cholesterol and maintain HDL (good) cholesterol. • Polyunsaturated fats: • These are found in sesame, corn, cottonseed and soybean oils. This type of fat has also been shown to reduce levels of LDL cholesterol, but too much can also lower your HDL cholesterol

38. Eat HealthyStay Healthy

39. Students selected for assignment

40. ASSIGNMENTS • Selected students are requested to prepare slides about one of the following topics (To be delivered before next lecture): • Lipids and disease • Healthy lipids • Unhealthy lipids • Atherosclerosis • Saturated Fatty acids • Unsaturated fatty acids • Triglyceridss

41. Study Questions Complete: • -----------,--------------------and------------------are essential fatty acids. • ----------------and --------------are saturated fatty acids. • All --------------and---------------are non essential amino acids. • ----------------------- is the parent compound of glycerophspholipids. • Lipids includes three main classes which are-----,--------and--------

42. Correct the incorrect word: 1-Essential amino acids are synthesized in human body. 2-Saturated fatty acids have one or more double bonds. 3- Alpha linolenic acid is non-essential amino acid. 4- Palmitoleic acid is essential amino acid.

43. Complete: • -----------,--------------------and------------------are essential fatty acids. • ----------------and --------------are saturated fatty acids. • All --------------and---------------are non essential amino acids. • ----------------------- is the parent compound of glycerophspholipids. • Lipids includes three main classes which are-----,--------and-------- Study Questions

44. 1-Essential amino acids are synthesized in human body. 2-Saturated fatty acids have one or more double bonds. 3- Alpha linolenic acid is non-essential amino acid. 4- Palmitoleic acid is essential amino acid. Correct the incorrect word:

45. Principles of Biochemistry, Donald J. Voet, Judith G. Voet, Charlotte W. pratt; Willey, 3rd ed. Suggested readings