1559T_ch26_454-46811/8/0511:55Pa9e467 EQA Solutions to Problems.467 H COOH NHCH-R CNHCH2R H COOH CI -COOCH2CH 人】 u+ COOH H COOCH.CH, H.NCH.CHCH.CC HO H.NCH.CHCH.CHCOOCH.CHs HO CI- HCHCHCH CHCOOH HNCHCHCHCHCOO HO HO e body i (ii) (c) There is no codon for Hyp in the table. Free Hyp is of no use to the body in the synthesis of collagen, because the body has no way of incorporating free Hyp into peptide chains. Gelatin does supply a lot of Pro, so it is useful in that regard, but it does not replace the indispensable need for vitamin C in collagen biosynthesis. H3NCH2CHCH2CHCOOH HO

Cl
HO Cl H2NCH2CHCH2CHCOO
HO Cl Hyp H3NCH2CHCH2CHCOOCH2CH3 H, H2O, hydrolyze ester HO Cl (Same mechanism as for lactone) H3NCH2CHCH2C OCH2CH3
CO2 HO O C O O Cl C H H3NCH2 COOCH2CH3 OH O O Cl H H H3NCH2 COOH COOH H2O
H COOCH2CH3 O O Cl H NHCH2R O OH COOH COOH H2O H
H H NHCH2R O H NCH2R O O NCH2R O OH O H2O H H H Solutions to Problems • 467 1559T_ch26_454-468 11/8/05 11:55 Page 467