1. Department of Chemistry CHEM1020 General Chemistry *********************************************** Instructor: Dr. Hong Zhang Foster Hall, Room 221 Tel: 931-6325 Email: hzhang@tntech.edu

2. CHEM1020/General Chemistry _________________________________________ Chapter 15. (L13)-Biochemistry Today’s Outline..Fats and other lipids Lipids Fatty acids Fats

3. Chapter 15. (L13)-Biochemistry Lipids …A lipid is a cellular component that is soluble in organic solvents of low polarity such as hexane, diethyl ether, or carbon tetrachloride. Lipids have common solubility properties. Lipids are insoluble in water. Lipids are not defined by functional groups. …Lipids include fatty acids, fats, steroids such as cholesterol and sex hormones, fat-soluble vitamins, waxes, and other substances.

4. Chapter 15. (L13)-Biochemistry Fatty acids …Fatty acids are long-chain carboxylic acids. Natural fatty acids almost always have an even number of carbons. Saturated fatty acids: Fatty acids without C-to-C double bonds Unsatuated fatty acids: Fatty acids with C-to-C double bond(s) -monounsaturated fatty acids: with only one –C=C– bond -polyunsaturated fatty acids: with more than one –C=C– bonds

5. Chapter 15. (L13)-Biochemistry Fats …A fat is an ester of fatty acids and the trihydroxy alcohol glycerol (Fig. 15.10 on pp.439) Fats are also called triglycerides or triacylglycerols. -Animal fats: Rich in saturated fatty acids, generally solids at room temperature -Vegetable fats, called oils: Rich in unsaturated fatty acids, liquid at room temperature

6. Chapter 15. (L13)-Biochemistry Iodine number and degree of unsaturation …Chlorine and bromine can readily add to C-to-C double bond: | | >C=C< + Br  -C-C- | | Br Br The iodine number is the number of grams of iodine that are consumed by 100 g of fat or oil. The higher the iodine number, the more unsaturation is. Generally, animal fats have low iodine numbers while vegetable fats have high iodine numbers (see Table 15.2 on pp. 440)

7. Chapter 15. (L13)-Biochemistry Iodine number and degree of unsaturation Typical iodine numbers for some fats and oils Fat or OilIodine No. Coconut oil8-10Oliver oil75-95 Butter25-40Peanut oil85-100 Beef tallow30-45Cottonseed oil100-117 Palm oil37-54Corn oil115-130 Lard45-70Fish oils120-180 Canola oil125-135 Soybean oil125-140 Safflower oil130-140 Sunflower oil130-145

8. Chapter 15. (L13)-Biochemistry Quiz Time A lipid is: (a) an inorganic compound; (b) a carbohydrate substance; (c) a cellular component that is soluble in organic solvents of low polarity such as hexane, diethyl ether, or carbon tetrachloride; (d) none of above.

9. Chapter 15. (L13)-Biochemistry Quiz Time Fatty acids are: (a) long-chain aldehydes; (b) short-chain carboxylic acids; (c) long-chain carboxylic acids; (d) long-chain alcohols.

10. Chapter 15. (L13)-Biochemistry Quiz Time Saturated fatty acids have: (a) C-to-C triple bonds only; (b) C-to-C double bonds only; (c) both C-to-C double and single bonds; (d) C-to-C single bonds only.

11. Chapter 15. (L13)-Biochemistry Quiz Time Unsaturated fatty acids have: (a) C-to-C triple bonds only; (b) C-to-C double bonds only; (c) both C-to-C double and single bonds; (d) C-to-C single bonds only.

12. Chapter 15. (L13)-Biochemistry Quiz Time A fat is: (a) an alcohol; (b) a carboxylic acid; (c) an ester of fatty acids and the trihydroxy alcohol glycerol ; (d) none of above.

13. Chapter 15. (L13)-Biochemistry Quiz Time Animal fats are: (a) generally rich in saturated alkanes; (b) generally rich in unsaturated fatty acids; (c) generally rich in saturated fatty acids; (d) none of above.

14. Chapter 15. (L13)-Biochemistry Quiz Time Vegetable fats or oils are: (a) generally rich in saturated alkanes; (b) generally rich in unsaturated fatty acids; (c) generally rich in saturated fatty acids; (d) none of above.

15. Chapter 15. (L13)-Biochemistry Quiz Time Fish oils are: (a) generally rich in saturated alkanes; (b) generally rich in unsaturated fatty acids; (c) generally rich in saturated fatty acids; (d) none of above.

16. Chapter 15. (L13)-Biochemistry Quiz Time Coconut oil is: (a) generally rich in saturated alkanes; (b) generally rich in unsaturated fatty acids; (c) generally rich in saturated fatty acids; (d) none of above.