Saturated fat and unsaturated fat The molecules of saturated fats can pack together, leading to high melting points NEo-C The molecules of unsaturated p一c、~八 ure 1s fats can not pack together, Co-c leading to low melting points stearic acid mp69c oleic acid m.p. 13C
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 22 52 pe anut 21 4 30 Olive 15 73 12 Corn 14 29 57 Soybean 14 24 62 Sunflower 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 Cholestero H-CH2 CH C D · Cholestero!:胆固醇 · Testosterone:睾酮 CH2OH estradiol Cortisol C-O ne of three estrogens · Estradiol:雌甾二醇 CHaO ogesterone Testosterone OH
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) Nucleophilic H2N COOH HN COOH Alanine(Ala, A) (Ser, S) Mw:71.09Mw:87.08.pKa-16Mw:10111,pKa~16Mw:103.15,pKa=8.35 H2N COOH H2N COOH COOH COOH Valine(Val, v) Leucine( Leu, L) soleucine(le, D) Methionine(Met, M) Proline MW:99.14 MW:113.16 MW:113.16 MW:131.19 COOH COOH HaN COOH Phenylalanine(Phe, F) Tyrosine(Tyr, Y) Tryptophan(Trp, W) Aspartic Acid (Asp, D) Glutamic Acid (Glu, E) MW:18621 MW:115.09pKa=39Mw:129.12,pKa=407 HN Amide H2N COOH H2N COoH HaN H2N COOH H2N COOH Asparagine(Asn, N) Glutamine(GIn, O) Histidine(His, H) Lysine(Lys, K) g MW:114.11 MW:128.14Mw:137.14.pKa=6.04MW:128.17,pKa=10.79Mw:156.19,pKa=1248 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(tBt).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 HC Hc NH (OH OH 2 HC Dipeptide NH OH 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