Ti liu n thi H-C 2010 Chuyn gọi l nhm thế amino ... +- R – COO-( đặc biệt ở trạng thi ... Tn gốc axyl của cc α-amino axit đầu N + tn α-amino axit

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  • Ti liu n thi H-C Chuyn :

    1 Copyright Thuyhoathaiphien.wordpress.com

    CHNG 3 : AMIN- AMINOAXIT- PROTEIN

    KIN THC C BN :

    AMIN

    I/ CU TRC- DANH PHP- NG PHN:

    Amin: khi thay th nguyn t hidro trong phn t NH3 bng gc hidrocacbon ta c hp cht amin

    Bc amin = s gc hidrocacbon lin kt vi N

    Amin n chc bc 1 : R-NH2 Amin n chc bc 2 : R NH R

    1

    Amin n chc bc 3 : R N R1

    R2

    Amin bo: nguyn t N lin kt vi gc hidrocacbon mch h

    Amin thm : Nguyn t N lin kt trc tip vi vng thm

    1/ Cng thc chung- c im cu to: -Cng thc tng qut ca amin : CxHyNt vi y 2x + 2 +t

    Vi : x,y,t > 0; nguyn ;nu y l t l v ngc li.

    - Cng thc tng qut ca amin n chc : CxHyN

    Cng thc ca amin no, n chc, mch h : CnH2n+3N (n 1)

    Amin n chc thm, nhnh no, mt vng benzen : CnH2n 5N (n 6)

    2/ Danh php :

    Tn gc chc :

    Tn thay th :

    Ghi ch : * C6H5NH2 c tn thng l Anilin

    * Nhm NH2 cn gi l nhm th amino

    II/ TNH CHT VT L:

    Metylamin,imetylamin, trimetylamin v etylamin l nhng cht kh, mi khai, c ,tan nhiu trong

    nc. Cc amin c phn t khi cao hn l cht lng hoc cht rn, nhit si tng dn v tan trong

    nc gim dn theo chiu tng ca phn t khi

    Anilin l cht lng, khng mu rt c, t tan trong nc

    II/ TNH CHT HA HC:

    1/ Tnh bazo: Trong nc : cc amin mch h ( metylamin, propylamin)to mi trng bazo yu lm qu tm

    ha xanh

    CH3NH2 + H2O [CH3NH3]+ + OH

    -

    Anilin v cc amin thm khc phn ng rt km vi nc nn khng lm i mu qu tm

    Lc bazo : CH3- NH2 > NH3 > C6H5NH2 Amin + axit to mui tan trong nc

    CH3NH2 + HCl CH3NH3Cl ( metyl amoniclorua)

    C6H5NH2 + HCl C6H5NH3Cl ( phenylamoniclorua)

    CH3NH2 + H- COOH H-COONH3-CH3 ( metylamonifomat)

    2/ Phn ng th nhn thm ca anilin: Anilin to kt ta trng vi ddBr2

    NH2 NH2

    + 3Br2 Br Br + 3HBr

    Br

    C6H5NH2 C6H2 Br 3NH2(2,4,6 tribromanilin)

    Tn gc hidrocacbon + amin

    Tn gc hidrocacbon tn mch cacbon- s ch v tr - amin

  • Ti liu n thi H-C Chuyn :

    2 Copyright Thuyhoathaiphien.wordpress.com

    Phn ng ny dng nhn bit Anilin

    KIN THC B SUNG:

    SO SNH TNH BAZO CA AMIN

    - Tnh baz ca amin l do i e t do cn li trn nguyn t nit ca amin tng linh ng

    Bin thin baz ph thuc vo gc R

    R y electron tnh bazo amin tng

    R rt electron tnh bazo amin gim

    C6H5NH2 < NH3 < CH3NH2 < (CH3)2NH

    - Amin bc 2 c tnh bazo mnh hn amin bc 1 v hn c amin bc 3

    Vd : (CH3)3N < CH3NH2 < (CH3)2NH

    Lu : R y electron : gc hidrocacbon no CH3 - < CH3-CH2 - < (CH3)2CH - < (CH3)3C

    Vd : NH3 < CH3NH2 < C2H5-NH2

    R rt electron : R c cha lin kt pi hay halogen

    CH2=CH - < C6H5 - < HC C- < halogen

  • Ti liu n thi H-C Chuyn :

    3 Copyright Thuyhoathaiphien.wordpress.com

    III/ TNH CHT HA HC:

    1) Tnh lng tnh:

    - Tnh bazo (ca nhm NH2 ) + axit Vd: HOOC-CH2-NH2 + HCl HOOC-CH2-NH3Cl

    -Tnh axit ( ca nhm COOH) + bazo Vd: H2N-CH2COOH + NaOH H2N-CH2COONa +

    H2O

    2) Tnh axit-bazo ca dd aminoaxit R(NH2)x(COOH)y vi x,y 1

    Trong dung dch : x = y aminoaxit khng i mu qu tm

    x > y amino axit lm qu tm ha xanh

    x < y amino axit lm qu tm ha

    3) Phn ng este ha: phn ng vi ancol ,xc tc axit v c

    Vd : H2N CH2- COOH + C2H5OH khiHCl H2N CH2- COOC2H5 + H2O

    ( hoc Cl-H3N

    +-CH2- COOC2H5 )

    4) Phn ng trng ngng : phn ng to lin kt peptit CO NH

    Vd: n H2N CH2 COOH 0t -(HN-CH2 CO)n- + n H2O

    ng dng : iu ch t poliamit (capron,enang,nilon...) v gii thch qu trnh tng hp protein

    PEPTIT V PROTEIN

    I/ PEPTIT:

    1/Peptit l nhng hp cht cha t 2 n 50 gc -amino axit lin kt vi nhau bng lin kt peptit

    Lin kt -CO- NH- gia 2 n v -amino axit c gi l lin kt peptit V d: H2N-CH2-CO-NH-CH-COOH

    CH3

    Lin kt peptit

    2) Phn loi: (gm 2 loi)

    -Oligopeptit: c t 2 n 10 gc -amino axit ( ty theo gi tr n ta c ipeptit, tripeptit,tetrapeptit)

    -Polipeptit: c t 11 n 50 gc -amino axit

    3) Cu to : Phn t peptit hp thnh t cc gc -amino axit qua lin kt peptit theo mt trt t nht

    nh : aminoaxit u N cn nhm NH2, amino axit u C cn nhm COOH

    4) ng phn : Vic thay i trt t sp xp cc amino axit trong mi phn t peptit s c cc peptit

    ng phn Vd: Hai peptit sau y khc nhau : Gly-Ala hoc Ala-Gly

    S lng peptit cha a cc gc aminoaxit, to ra t a phn t aminoaxit khc nhau l a! peptit

    S -amino axit a = 2 3 4 5 ..

    S peptit tao ra a! = 2 6 24 120....

    Vd: Hn hp gm Glyxin, alanin, valin to ra 3! = 6 tripeptit c mt ng thi 3 aminoaxit trn :

    Gly-Ala-Val Ala-Val-Gly Val-Gly-Ala Gly-Val Ala Ala-Gly-Val Val Ala Gly

    S lng peptit cha n gc aminoaxit (c th trng nhau)t a phn t aminoaxit ( n a) l an

    Vd: *Hn hp Glyxin v Alanin to ra 23 = 8 cc tripeptit

    Gly Gly Gly Ala Ala Ala Gly Ala Ala Ala Gly Ala

    Ala Ala Gly Ala Gly Gly Gly Ala Gly Gly Gly Ala

    *Hn hp Glyxin, alanin, valin to ra 33 = 27 cc tripeptit

    5) Danh php : Tn gc axyl ca cc -amino axit u N + tn -amino axit u C

    6) Tnh cht ha hc :

    a. Phn ng mu biure: Peptit + Cu(OH)2 -> phc mu tm

    Ch : i peptit khng c phn ng ny

    b. Phn ng thu phn:Khi un nng dd peptit vi axit hoc kim s thu c dd khng cn phn

    ng mu biure l do peptit b thy phn thnh hn hp cc -amino axit

    PROTEIN

    1/ - Protein l nhng polipeptit cao phn t c pt khi t vi chc nghn n vi triu.

    2/ Phn loi: Protein gm 2 loi:

    + Protein n gin: c to thnh t cc gc -aminoaxit

  • Ti liu n thi H-C Chuyn :

    4 Copyright Thuyhoathaiphien.wordpress.com

    + Protein phc tp: c to thnh t protein n gin cng vi thnh phn phi protein nh axit

    nucleic, lipit, cacbonhidrat

    3/ Tnh cht vt l : Khi un nng hoc cho axit hay bazo, hay mt s mui vo dd protein, protein s ng t li , tch ra

    khi dd ( gi l s ng t protein)

    4/ Tnh cht ha hc:

    a. P thy phn:

    Protein polipeptit cc - aminoaxit

    b/ Phn ng mu

    + P vi Cu(OH)2 (p biure) Protein + Cu(OH)2 phc mu tm

    + P vi HNO3 c Protein + HNO3c kt ta mu vng

    TON XC NH CTPT- CTCT CA AMINO AXIT

    Phng php:

    -Cng thc tng qut ca aminoaxit : CxHyOzNt hoc R(NH2)x(COOH)y

    - CTTQ : - amino axit : R- CH(NH2)COOH - Xc nh CTPT ca aminoaxit c th da vo :

    + Phn ng t chy aminoaxit:

    CxHyOzNt + (x + y/4 z/2) O2 0t x CO2 + y/4 H2O + t/2 N2

    + Da vo tnh cht lng tnh ca aminoaxit :

    R(NH2)x(COOH)y

    Vi : x = min

    HCl

    a oaxit

    n

    n ; y =

    min

    NaOH

    a oaxit

    n

    n

    Kt hp x, y vi Maminoaxit R CTPT

    Lu : C th xc nh x,ythng qua mui ca aminoaxit

    R(NH2)x(COONa)y + (x+y) HCl R(NH2.HCl)x(COOH)y + yNaCl