Saturated fat and unsaturated fat The molecules of saturated fats can pack together, leading to high melting points The molecules of unsaturated fats can not pack together, CHo-c w知 D 1n irai oier属 leading to low melting points stearic acid,mp69℃ oleic acid,mp.13℃
Saturated fat and unsaturated fat The molecules of saturated fats can pack together, leading to high melting points. The molecules of unsaturated fats can not pack together, leading to low melting points. stearic acid，m.p.69℃ oleic acid，m.p.13℃
Fats from animals and plants are mixture of different fat molecules Table 13. 1 degree of unsaturation in some common fats Fat Percentage of total fatty acid content Saturated Monounsaturated polyunsaturated Coconut 93 6 Palm 57 36 7 Lard 44 46 10 Cottonseed 26 52 peanut 21 24 30 Olive 15 12 Corn 14 29 57 Soybean 14 24 62 Sunflower 11 49 70 Safflower 10 14 76 Canola oil 58 36
Fats from animals and plants are mixture of different fat molecules Table 13.1 degree of unsaturation in some common fats Fat Percentage of total fatty acid content Saturated Monounsaturated polyunsaturated Coconut 93 6 1 Palm 57 36 7 Lard 44 46 10 Cottonseed 26 22 52 peanut 21 4 30 Olive 15 73 12 Corn 14 29 57 Soybean 14 24 62 Sunflower 11 49 70 Safflower 10 14 76 Canola oil 6 58 36
Steroids(类固醇) contain four carbon rings Cholesterol CH-CH,-CH -CH-CH C Cholestero!:胆固醇 Testosterone:睾酮 CHOH estradiol Cortisol C=O (one of three estrogens)OH Estradio!:雌甾二醇 CH3 LOH Progesterone Testosterone
Steroids (类固醇) contain four carbon rings • Cholesterol: 胆固醇 • Testosterone: 睾酮 • Estradiol: 雌甾二醇
134 Proteins are polymers of amino acids(氨基酸) Nucle。 phili COOH COOH Alanine(Ala, A) (Ser, S) Mw:57.05 M:71.09 MW: 87.08, pK a- 16 MV H2N COoH H2N COOH H2N COOH Valine(VaL, v) Leucine( Leu, L) Isoleucine(le, I) Methionine(Met Proline(Pro, P) MWw:99.14 W:113.1 Mw:113.16 MW:131.19 Aromatic H Acidic H2N COoH COOH Phenylalanine(Phe, F) Tyrosine (Tyr, Y Tryptophan (Trp, W) Aspartic Acid(Asp, Glutamic Acid(Glu, E) W:147.18 MW:163.18 MW:186.21 Mw:115.09,pKa= Mw:129.12,pKa=4.07 Amide Basic NH3+ NH+ H COOH H2N COOH H2N COOH paragine(Asn. Arginine(Arg, R) MW:12814MW:137.14,pKa=604Mw:128.17,pKa=10.79Mw:156.19,pKa=12.48 20 amino acids differ from one another by the chemical identity of their side groups
13.4 Proteins are polymers of amino acids (氨基酸) • 20 amino acids differ from one another by the chemical identity of their side groups
Amino acids are linked through peptide bonds(zt).A group of amino acids linked together through peptide bonds is called peptide. Peptides containing more than ten amino acids are generally called polypeptides Amino acid 1 Amino acid 2 R 2 HC一 +HC一 NH. (OH NH H H HO 2 HC ipep tide H Peptide bond
• Amino acids are linked through peptide bonds (肽键). A group of amino acids linked together through peptide bonds is called peptide. Peptides containing more than ten amino acids are generally called polypeptides