Question

LIPIDS a. Draw a triglyceride containing palmitic, stearic, and oleic acids, identify each one. b. Consider a triglyceride containing three oleic acids: compare its melting point and iodine number to the triglyceride in (a); describe how hydrogenation would affect these attributes. C. Draw the chemical structures of phosphatidylcholine and sphingomyelin; explain their similarities and differences, including the types of water-labile linkages (bonds) present in each. d. What is meant by "good cholesterol" and "bad cholesterol?" e. How do manufacturers get the cholesterol out of peanut butter?

Answer 1

5) a) palmitic acid Stearic acid Glycerol Oleic acid 5)b) Oleic acid Glycerol Oleic acid Oleic acid 5a S.No 5b Melting point is high due to presence of Melting point is low due to presence of saturated fatty acids unsaturated fatty acids lodine Number: the mass of iodine in grams that is consumed by 100 grams of a triglyceride. The higher the iodine number, the more C=C bonds are present in the triglyceride. 2 lodine number is low due to only one double lodine number is high due to three double bond bond containing oleic acid is present. containing oleic acids are present. Hydrogenation: is the process of adding hydrogen across double bonds to yield saturated triglycerides H2, Pd/C oleic acid After hydrogenation it fully converted into saturated triglyceride (palmitic, stearic, stearic) melting point further increases and lodine become zero After hydrogenation it converted into saturated triglyceride(stearic, stearic, stearic) melting point further increases and lodine become zero

5)c) palmitic acid Glycerol - 80 choline Oleic acid 1-Oleoyl-2-palmitoyl-phosphatidylcholine R.CHOH.CH.CH2-O-P-O-CH2CH2N (CH3)3 sphingomyelin NHOC. RO HOH & CH₂ ΝΗ Η Το CH3 CH3 =0 N-Chexadecanoyl)-sphi ng-4-enine-1-phosphocholine S.No 1 2 phosphatidylcholine Sphingomyelin Similarities Both contains phosphate and choline | Both contains phosphate and choline moiety moiety Fatty acid Fatty acid Differences Fatty acid in ester form Fatty acid in amide form Ester bonds Amide bonds Hydroxyl group present Water labile groups are ester and choline Water labile groups are amide and choline

5)d) Good cholesterol: high-density lipoprotein is called good cholesterol Bad cholesterol: low-density lipoprotein is called bad cholesterol 5)) As per my knowledge, any vegetable oil or any seed doesn't contain cholesterol. The main source of cholesterol is animal fat. Please cross check once.