Thiết kế bài giảng hóa học 12 (tập 1) phần 2

Hogt dpng cda GV GV bd sung: Anilin va cac amin tham phan ling rat kem vdi nude va tinh baza cua anilin rdt ylu ylu hon CH3NH2, NH3 nen khdng lam quy tim ddi mau phenolptalein GV ti

ChiFcyng 3 AMIN, AMINO AXIT VA PROTEIN

• Tinh chat vat li: Quy luat bien ddi do tan, nhiet do sdi ciia cac amin

• Tinh chdt boa hgc: Tinh baza cua amin, phan iing the d nhan benzen cua anilin

HS hiiu:

Nguyen nhan gay ra tinh baza cho cac amin, tai sao anilin khdng lam quy, phenolphtalein ddi mau?

2 KT nang

• Nhan dang cac hgp chat amin

• Viet chinh xac cac phuang trinh hda hgc

• Quan sat, phan tich cac thi nghiem chiing minh ciia amin

• So sanh lire baza giira cac amin vdi nhau va vdi NH3

3 Tinh cam, thai do

• Hieu dugc each giai quyet mau thuan giiia cau tao va tinh chat hoa hgc cua ciia amin tao nen sir himg thii khi giai quyet van de mdi

• Thay dugc tam quan trgng cac amin trong ddi sdng va san xuat gay hiing thu cho HS khi hgc bai nay

B C H U A N B! CUA GV VA HS

• GV: - May tinh, may chieu, cac phieu hgc tap

- Hoa chat: NH3, anilin, metyl amin, nude cat, quy tim, nude brom

- Dung cu: Ong nghiem, cap dng nghiem, bd gia thi nghiem

• HS: Xem trudc bai amin

C TI^N TRINH D A Y - HOC

Hogt dpng cua GV Hogt dpng ciia HS

Hogt dpng I

I KHAI NIEM, PHAN LOAI VA DANH PHAP

1. K H A I NIEM, PHAN LOAI

GV chieu len man hinh cac cdng thiic

NH3, CH3NH2, CH3-NH-CH3, (CH3)3N

Yeu cau HS: So sanh cau tao ciia NH3

vdi cac chat cdn lai Biet cac chat dd la

amin tir dd neu khai niem amin?

GV yeu cau HS: Lap day ddng ddng cua

amin no don chiic, mach hd

GV: Tuong tu viet cdng thiic tdng quat

ciia cac amin la ddng dang cua C6H7N

GV yeu cau HS: Viet ddng phan va ggi

ten cac chat cd cdng thiic phan tir

C2HeO

GV gidi thieu tuong tu C2HeO thi amin

ciing cd cac ddng phan vi tri nhdm N

Yeu cau HS: Viet ten cac amin cd cdng

N, cac chat khac cd gdc hidrocacbon lien ket vdi N cua NH3

- Khai niem: Khi thay thi nguyen tir H trong phan tir NH3 bang gdc hidro cacbon ta thu dugc amin

HS thao luan:

Tir cdng thirc amin don gian nhdt CH5N —> ddng dang cd dang CH5(CH2)kN^Ck+,H2k+5N

Dat k+1 = n -> CnH2n+3N (n> 1) HS: Cdng thiic la CnH2n-5N (n>6)

129

Hogt dpng cua GV

(1), (4), (7) la amin bac I

(2), (3), (5) la amin bac II

(6) la amin bac III

GV yeu cdu: Neu khai niem bac amin

GV luu y: Cdn phan biet bac amin va

bac ancol

GV: Tir nhung ddng phan da vilt thi

amin cd nhiing d^ng ddng phan nao?

Hogt dpng cda HS

GV cho HS nghien ciiu SGK va dat vdn

de traJdi cac cau hdi

- Cd thi chia amin thanh nhiing loai

nao? - Cho vi du minh hga

CH3-CH2-N(CH3)2 (6) (CH3)3C-NH2 (7)

HS thao luan:

Bac amin la sd nguyen tir H trong phan tir NH3 bi thay thi

HS: thao luan va nhan xet

Amin cd cac loai ddng phan:

+ amin thom: CeH H2, CH3C6H4NH2

- Theo bac amin + amin bac mgt: CH3NH2, C6H5NH2 + amin bac hai: CH3-NH-CH3, CH3-NH-CeH5

+ amin bac ba: (CH3)3N

Hogt dpng 2

2 DANH P H A P

GV chilu len bang 3.1 (SGK) len man

hinh cho HS quan sat va yeu cdu:

- Cd bao nhieu each ggi ten?

HS quan sat,thao luan dua ra nhan xet

Cd 2 each ggi ten

+ Ten gdc-chiic: cd cau tnic Ten amin = Ank + yl + amin

Hogt dpng cda GV

- Neu quy tac ggi ten amin?

- Ggi ten cac amin sau day?

CH3-CH(CH3)-CH2-NH2

(CH3)3C-NH2

CH3-NH-C2H5

0-CH3-C6H5NH2

GV bd sung: Neu cd nhieu nhdm chiic

amin thi them cac tiep dau ngii di, tri

Vi du: NH2-(CH2)6-NH2

hexametylendiamin

GV chieu len man hinh bai tap len man

hinh cho HS thao luan

Vilt ten Cac amin cd ten sau day:

dimetylamin, phenylamin, benzylamin

hexan-1,6-diamin, o-metylpheylamin

etylmetylamin

Hogt dpng cda HS + Ten thay thi: cd cdu tnic

Ten amin = Ankan + vi tri + amin + Ten thdng thudng chi ap dung cho mgt sd amin

Vi du: C6H5NH2 anilin

HS thao luan:

Dimetylamin: CH3-NH-CH3 Phenylamin: C6H5NH2 Benzylamin: C6H5CH2NH2 Hexan-1,6-diamin: NH2(CH2)6NH2 o-metylpheylamin NH2

^ [^"'

Etylmetylamin: C2H5-NH-CH3

Hogt dpng 3

II TINH C H A T VAT LI

GV cho HS nghien ciiu SGK va yeu cau

HS nhan xet ve:

- Trang thai (d nhiet do thudng)

- Sir bien thien ve do tan

- Trang thai, mau sac, kha nang hda tan

cua anilin

- Giai thich tai sao anilin de lau ngay

trong khdng khi thi cd mau den

HS: Nghien ciiu SGK va nhan xet

- Trang thai

Metylamin, dimetylamin, trimetylamin etylamin la chat khi cd mau khai khd chju Cac amin khac la chat Idng hoac ran

- La cac hgp chat khdng mau, 4 amin dau deu tan tdt trong nude, thii tu cac amin cd do tan giam theo chieu tang phan tir khdi

Hogt dpng cua GV Hogt dpng cda HS

GV nhan xet va bd sung: tat ca cac amin

deu ddc nhu nicotin, anilin

GV chilu len man hinh bang sau

C3H8 -42°C

va dat vdn dl: Tai sao amin va ancol cd

phan tir khdi xdp xi nhau ma nhiet do

sdi chenh lech nhau rat Idn

GV hudng dan HS giai quylt vdn dl

- So sanh thanh phdn cau tao cua 3 chat

tren

- YIU td nao anh hudng din nhiet do

sdi

- Tai sao ancol cd nhiet do sdi cao nhat

GV: Vay amin cd lien ket hidro hay

khdng? NIU cd hay so sanh lien ket

hidro cua ancol va amin

- Anilin la chdt Idng khdng mau sdi d 184°C, it tan trong nude, tan nhilu trong dung mdi hiiu ca

- D I lau anilin ngoai khdng khi thi co mau den do anilin bi oxi khdng khi oxi hda

HS quan sat

HS thao luan va nhan xet

- DIU cd phan tii' khdi xdp xi nhau

- Khac nhau la do:

C3H8 gdm cd C,H khdng cd nhdm chuc C2H5OH cd nhdm chiic hidroxyl C2H5NH2 cd nhdm chiic amin

- Nhdm chiic anh hudng tdi nhiet do sdi

- Ancol cd nhdm OH phdn cue nen co lien ket hidro

HS: Theo khai niem vl lien kit hidro thi amin cd lien ket hidro

Lien kit N-H kem phan cue hon lien kit 0-H nen lien ket hidro ciia amin ylu ban lien ket hidro ciia ancol

Hogt dpng cda GV

GV yeu cau HS kit luan vdn dl

Hogt dpng cua HS

HS ket luan van de:

Amin cd lien ket hidro yeu han ancol nen cd nhiet do sdi thap ban ancol va ankan

Hogt dpng 4

III CAU TAO PHAN T i j VA TINH C H A T H O A H O C

LCAUTAOPHANTLT

Cdch 1:

GV yeu cau HS len bang viet cdng thirc

cau tao va neu dac diem cau triic ciia

phan tir NH3

GV gidi thieu cho HS bilt: Amin cd cdu

tao gidng vdi NH3 Yeu cau mdt HS len

bang vilt cdu tao cua metylamin

dimetylamin, trimetylamin, anilin

GV yeu cdu HS du doan tinh chdt hda

H H H NH3 cd cau tao dang hinh thap 1 dinh

la N va 3 dinh cdn lai la H, tren nguyen tir N cdn cd 1 cap electron tu do (chua lien ket)

HS len bang viet cdng thiic cau tao

N / N ,

CH3 H H ^ " 3 CH3 H metylamin dimetylamin

N N / / \ / / \

CH3 CH3 CH3 H H C6H5 trimetylamin anilin

HS thao luan va nhan xet:

Hogt dpng cda GV

Cdch 2:

GV chieu hinh 3.2 SGK len man hinh

(hoac cho HS nghien ciiu SGK) yeu cdu

HS nhan xet ve:

- Cau tao cua NH3 va cac amin

- Du doan tinh chat hda hgc ciia amin

Hogt dpng cua HS

Amin cd cdu tao tuong tu amoniac

- Tinh baza

- Tinh khir

- Tinh chat cua gdc hidrocacbon

HS quan sat (nghien cim SGK)

- Cau tao cua amin tuong tu NH3

- Tinh chat cua amin tuang tu NH3 + Tinh baza

+ Tinh chat ciia gdc hidrocacbon + Tinh khir

Hogt dpng 5

2 TINH C H A T H O A HOC

a) Tinh bazff

GV lam thi nghiem Nhiing giay quy

vao cac dung dich sau: metylamin,

amoniac, anilin Yeu cau HS quan sat,

neu hien tugng va giai thich

GV dieu khien, hudng dan HS giai

+ Ong dung anilin quy tim Ichdng doi mau

- Giai thich:

Metyl amin va nhieu amin khac khi tan vao nude phan ung vdi nude tuong tu NH3 sinh ra ion OH"

>TTT _ i _ T I / ^ \ PTiTTT T*" 1 ( ^ T T ~

NH3 + H2O < > [NH4] + OH CH3NH2 + H20 < > [CH3NH3]

+ 0H'

Vi vay CH3NH2, NH3 lam quy tim hda xanh

Hogt dpng cda GV

GV bd sung: Anilin va cac amin tham

phan ling rat kem vdi nude va tinh baza

cua anilin rdt ylu (ylu hon CH3NH2,

NH3) nen khdng lam quy tim ddi mau

phenolptalein

GV tiep tuc lam thi nghiem:

Nhd vai gigt dung dich vao 2 dng

nghiem Ong nghiem 1: dung nude cdt

dng nghiem 2: dung dung dich HCl

Yeu cau HS:

- Quan sat

- Neu hien tugng

- Giai thich

GV dat vdn dl: Tai sao amin beo(ankyl

amin) lai cd tinh baza manh hon anilin?

GV dilu khiln hudng dan HS giai quylt

HS quan sat va nhan xet:

- Ong 1 thay anilin hau nhu khdng tan, lang xudng day dng nghiem

- Ong 2 thay anilin tan

Giai thich:

+ Anilin hau nhu khdng tac dung vdi nude nen anilin hau nhu khdng tan, nd tao van due rdi lang xudng day

+ Anilin tan dugc trong HCl do cd phan ling tao ra hgp chat tan trong nude

cd kha nang nhan proton (H"*^)-> cd tinh baza

135

Hogt dpng cda GV Hogt dpng cda HS

- So sanh cap electron tu do trong NH3

va trong ankyl amin (VD: metyl amin)

- So sanh cap electron tu do trong NH3

va trong anilin

GV yeu cau HS ket luan van de

GV chieu bai tap sau len man hinh cho

tu do tren nguyen tir N tang -^ de cho

cap electron tu do nay (de cdng H'*') hon nen cd tinh baza manh hon NH3

- Tuong tu vdi NH3 va CeH5NH2 thi nhdm CeHs cd hieu iing hut electron cua nhdm NH2 lam giam mat do electron cua nguyen tir N so vdi mat do electron trong NH3

H H H H H CsH 6 0 5

-> lam giam kha nang nhan H'*^ -^ tinh

baza ciia anilin nhd ban cua NH3 HS: Tinh baza ciia anilin cd the manh ban hay yeu hon NH3 tuy thudc vao gdc hidrocacbon lien ket vdi nita

HS thao luan:

Chgn dap an C

GV: Tuang tu NH3 hay vilt phuong

trinh hda hgc ciia metylamin vdi dung

dich FeCl3

GV yeu cau HS: Viet phuang trinh hda

hgc chay tdng quat cua day ddng dang

„ _ , , 6n + 3 _

2 C n H 2 n + 3 N + ^ ; — 0 2 ^

2 2nC02 + (2n + 3)H20 + N2

Hogt dpng 6 b) Phdn ling the & nhan tham cda anilin

GV lam thi nghiem:

Cho vai gigt dung dich Br2 vao 2 dng

nghiem: dng 1 la dung dich metyl amin,

dng 2 la dung dich anilin rdi lac nhe

- Phuong trinh hda hgc NH2 NH,

JL JL [ Q ] + 3 B r 2 ^ ^ ' • " O " ^ ' +3HBr

^ ^ ^ ^ ^ ( t r a n g )

Hogt dpng cda GV

GV bd sung phan iing nay de nhan bilt

anilin

GV yeu cau HS: Chiing minh sir anh

hudng qua lai giiia gdc phenyl vdi nhdm

chiic amin

GV gidi thieu cho HS biet cac amin cd

img dung:

- Amin dugc dung trong tdng hgp hiru

CO Dac biet la cac diamin diing de tdng

hgp polime

Vi du: Anilin la nguyen lieu trong cdng

nghiep pham nhugm, polime, dugc

pham

- Dieu che amin cd nhieu each nhu:

+ Thay the nguyen tir H trong phan tir

CeH5N02 +[H](F^+Hci) ^ CeH5NH3Cl

nguyen tir C tai cac vi tri ortho-para -^

de tham gia phan img the brom

- Nhdm CeHs hut electron cua nhdm NH2 lam cho cap electron tu do cua N

bi giii chat ban -^ lam giam tinh baza

HS lang nghe va ghi bai

HS hoan thanh cac sa dd

CH3I + NH3 -^ CH3NH2 + HI CH3I + CH3NH2 -^ (CH3)2NH + HI CH3I + (CH3)2NH -^ (CH3)3N + HI C6H5NO2 + 7HCldu +3Fe -^

C6H5NH3CI + 3FeCl2 + 2H2O

Hogt dpng cda GV Hogt dpng cua HS

Hogt dpng 7

CUNG CO B A I V A B A I T A P VE N H A

GV nhac lai cac ndi dung chinh da hgc

Yeu cau HS luu y cac diem chinh sau:

- Khai niem amin

- Bac amin (phan biet vdi bac ancol)

- Danh phap amin

- Tinh chat vat li

- Tinh chat ciia amin la tinh bazo (so

sanh tinh baza cua cac amin vdi NH3),

phan ling the ciia cac anilin

- Ung dung cua amin

GV chieu cac bai tap sau len man hinh

cho HS ciing cd

\ Cd bao nhieu ddng phan la amin bac

hai trong cdng thirc C4H9N

4 D I trung hda 25 gam dung dich ciia

mdt amin don chiic X ndng do 12,4%)

cdn diing 100ml dung dich HCl IM

Cdng thiic phan tir cua X la

A C3H5N

B C3H7N

C CHsN

D C2H7N

Bii tap ve nha 1, 2 , 3 , 4 , 5 , 6 (SGK)

D HU'd/NG D A N GIAI BAI TAP TRONG SGK

C H 3 - N - C H 3 amin bac hai

CfiHsONa, NaOH du

+ Sue CO2 du

C6H6, C5H5NH2

+ dd HCl lac deu, chiit

CfiHsOH ddNaHC03 CgHe C6H5NH3CI, HCl du

+ dd NaOH du

C6H5NH2 NaCI

5 a) Dung dung dich axit

b) Dimg giam de khir miii tanh

6- Mc^H,Br3NH, = 330 g

a) Phuang trinh hda hgc

CeH5NH2 + 3Br2 -^ CeH2Br3NH2i + 3HBr

3 mol 330gam 0,04 mol 4,4 gam

0,04.160.100 ,,^ , , ,, Vdd Br33% = J Y l " ' ^^ ^ b) Phuang trinh hda hgc

C6HsNH2 + 3Br2 -^ C6H2Br3NH24 + 3HBr

1 mol 330gam

0,02 mol 6,6 gam

^QHsWH, = 0,02.93 = 1,86 gam

Bai 10 AMINO AXIT

A MUC TIEU BAI HOC

1 KIdn thu'c

HS biit:

• Khai niem, img dung va vai trd amino axit

• Dua vao dac diem cau tao de suy ra amino axit vira cd tinh axit vira cd tinh baza

• Biet dinh nghia, dieu kien monome ciia phan img triing ngung

HS hieu: Cau tnic phan tir va tinh chat hda hgc ca ban cua cac amino axit

2 KT nang

• Nhan biet va ggi ten amino axit

• Viet cac phuang trinh hda hgc ciia amino axit

• Quan sat, giai thich cac thi nghiem chimg minh

3 Tinh cam, thai do

Amino axit cd tam quan trgng trong viec tdng hgp ra protein, quyet dinh sir sdng, khi nam cac tinh chat ca ban cua nd (dinh nghia, danh phap va cac tinh chdt dac trung ciia nd) se tao himg thii cho HS khi nghien ciiu bai nay

Mdi quan he giiia hgp chdt cd hai nhdm chiic (axit va baza) ddi lap nhau lai tdn tai trong mdt hgp chdt Se cd nhiing tinh chdt mdi kich thich sir td md ciia HS tham gia kham pha

B C H U A N Bj CUA GV VA HS

• GV: - May tinh, may chieu, cac phieu hgc tap

- Hinh anh, tranh ve lien quan bai hgc

- Hoa chat: Quy tim, glyxin, axit glutamic, lysin

- Dung cu: dng nghiem, cap dng nghiem

• HS: On tap kien thirc li thuyet, phuong phap giai bai tap ve amin va xem udc bai amino axit

tr-C TI^N TRiNH DAY- HOC

GV chieu ndi dung bai tap len man hinh

yeu cau 2 HS len bang trinh bay, cac

HS khac chuan bi de nhan xet va bd

sung

I De trung hda 25 gam dung dich ciia

mdt amin don chirc X ndng do 12,4%)

cdn dung 100ml dung dich HCl IM

Cdng thiic phan tir cua X la

A C3HsN B C3H7N

C CHsN D C2H7N

2 Cau nao dudi day khong diing?

A Cac amin deu cd tinh baza

B Tinh amin cua tat ca cac baza deu

manh ban NH3

C Anilin cd tinh baza ylu hon NH3

D Tdt ca cac amin don chiic deu chiia

mdt sd le nguyen tu H trong phan

Hogt dpng cda GV Hogt dpng cda HS

NH2 Yeu cau HS neu:

- Khai nifm amino axit

- Cdng thirc tdng quat

GV chieu len bang hinh 3.2 yeu cau HS

nhan xet:

- Cd bao nhieu each ggi ten amino axit

- Quy tac ggi ten cua moi each

- Cho vi du

HS quan sat, thao luan va nhan xet:

Amino axit la hgp chat hiiu ca tap chiic

ma phan tir chiia ddng thdi nhdm amino (NH2) va nhdm cacboxyl (COOH)

Cdng thirc tdng quat la:

(NH2)xR(C00H)y (X, y >1)

R la gdc hidrocacbon

HS quan sat, thao luan

- Cd 3 each ggi ten amino axit + Ten thay the: Cd cau triic axit + vi tri + amino + ten axit

2 1

VD: C H, - C OOH axit-2-amino

1 ^

1 NH2 etanoic -

CH3 - C H - C H - COOH CH3 NH2

Axit-2-amino-3-metylbutanoic + Ten ban he thdng

Xet vi tri tuong ddi ciia nhdm amino trong mach cacbon

Hogt dpng ciia GV Hogt dpng cua HS

GV bd sung:

+ Ten thay the thi ten axit dugc ggi

theo ten thay the

+ Ten ban he thdng thi axit ggi theo ten

thdng thudng

GV yeu cau HS nam vung cdng thiic

cau tao, cac each ggi ten cua amino axit

axit a - aminopropionic HOOCCH2-CH2-CH-COOH

NH2 Axit a-aminoglutamic Ten thdng thudng khdng theo quy tdc, ggi theo bang ten rieng

HS lang nghe va ghi bai

Hogt dpng cda GV Hogt dpng cda HS

Ho ft dpng 3

II CAU T^O PHAN TU' VA TINH CHAT HOA HQC

LCAUTAOPHANTIT GV: Viet cdng thiirc cau tag cua

NH2-CH2-COOH len bang yeu cduHS

nhan xet dac diem cau tao

GV hudng dan HS nhan xet

- Dac diem nhdm COOH

- Dac diem nhdm NH2

- Sir tuong tac giura 2 nhdm

GV yeu cdu HS du doan tinh chdt vat li

cuaamino axit

GV nhan xet va bd sung:

- Amino axit khdng bay hoi ndng chay,

phan buy d nhiet do tuong doi cao

- Khdng tan trong dung mdi khdng

phan cue nhu dau hda, benzen, ete ma

tan tdt trong nude

- Amino axit thudng cd vi nggt (mi

HS thao luan va nhan xet: Nhdm COOH cho proton cdn nhdm NH2 nhan proton ciia nhdm COOH

NH2CH2COOH < >

NH2CH2COO"+H' NH2CH2COO" + H ( >

NH3^CH2COO"

HS thao luan

Do cac amino axit la nhiing hgp chat ion ludng cue -> a dilu kien thudng la chat ran ket tinh, de tan trong nude co nhiet do ndng chay cao (tinh chdt ciia hgp chat ion)

HS lang nghe va ghi bai

Hogt dpng 4

2 TINH C H A T H O A H O C

GV yeu cau HS du doan tinh chdt hda

hgc ciia amino axit

HS thao luan va nhan xet:

Hogt dpng cua GV

a) Tinh chat ludng tinh

GV yeu cdu HS vilt phuang trinh hda

hgc cua glyxin vdi HCl, NaOH va nit ra

tinh chdt chung cua amino axit

Hogt dpng cua HS

b) Tfnh chdt bazar cUa amino axit

GV lam thi nghiem nhiing mdu gidy

quy vao dung dich glyxin, axit

glutamic, Iysin Yeu cdu HS quan sat

neu hien tugng va giai thich

- Cd nhdm NH2 cd tinh chat cua mdt baza

- Cd nhdm COOH cd tinh chdt cua mgt axit-> amino axit cd tinh luong tinh

HS thao luan va nhan xet:

- Phuang trinh hda hgc NH2CH2COOH + HCl -^

HS quan sat, thao luan va giai thich

NH3^CH2COO-Hogt dpng cua GV

GV nhan xet bd sung amino axit cd

cdng thirc (NH2)xR(C00H)y

Neu X = y quy tim khdng ddi mau

Neu X > y quy tim khdng hda xanh

Neu X < y quy tim khdng hda dd

Hogt dpng cua HS

H2NC3Hs(COOH)2 < »

-OOC-C3H5-COO->JH3 Tao ra H"^ lam quy ddi mau

Tuong tu glysin tao ra OH" lam hda xanh

Hogt dpng 5 c) Phdn iing riing cda nhdm-COOH: phdn img este hoa

GV yeu cau HS viet phan iing este hda

giira glyxin vdi etahol

GV nhan xet va bd sung:

Thuc ra este dugc hinh thanh dudi dang

- Ngoai ra amino axit cdn cd the tac

dung vdi HNO2 thi amino axit dugc

chuyen thanh hidroxi axit Yeu cau HS

viet phuong trinh hda hgc

- Phan img nay dugc diing de dinh

lugng nhdm amin trong amino axit

ciing nhu trong protein

HS viet phuang trinh hda hgc

T T Tl T O T T O / ^ /^J T f f~^ J J i'~\T T S

H2N-CH2COOH + C2H5OH < •*

NH2CH:COOC2H5 +

HS lang nghe va g' oai

HS viet phuang trinh hda hgc

Hogt dpng cua GV

GV gidi thieu cho HS:' Ngoai cac tinh

chat ciia cac a-amino axit cdn tao vdi

ion ddng vao mdt sd kim lt)ai khac

nhirng mudi ndi phiic mau it tan, rdt

ben

Hogt dpng cua HS

HS ghi bai

Hogt dpng 6 d) Phan img triing ngung

GV cho HS nghien ciiu SGK va yeu

cduHS:

- Khai niem phan iing trung ngung

- Dieu kien de cac amino axit thuc hien

phan ling triing ngung

- Viet phuang trinh hda hgc phan iing

triing ngung e-amino caproic

- Dac diem phan img triing ngung amino

- Dieu kien de cac amino axit thirc hien phan ling triing ngmig la cd tir 2 nhdm chirc trd len cd kha nang phan img

- Phuong trinh hda hgc

nH2N(CH2)sCOOH —^

axit s-amino caproic

(-NH-(CH2)5-CO-)„+nH20 Policaproamit

- Dac diem phan img triing ngung amino axit la nhdm -OH ciia nhdm -COOH ciia phan tir nay ket hgp cimg H chiia nhdm NH2 ciia phan tir kia thanh H2O va sinh ra polime

Hogt dpng 7

III iTNG DUNG

GV cho HS nghien ciiu SGK va yeu

cau HS neu nhirng iing dung ca ban cua

amino axit

HS nghien ciru SGK va nhan xet

- Amino axit thien nhien la ca sd kien tao protein cua co the sdng

149

Hogt dpng cUa GV Hogt dpng cda HS

GV nhan xet va gidi thieu cho HS cdng

thiic cau tao mi chinh (hay bdt nggt)

- Axit e-amino caproic, axit co-amino enantoic la nguyen lieu de san xuat to nilon

Hoat dpng 8

CUNG CO BAI - BAI T A P VE N H A

GV nhac lai cac ndi dung chinh da hoc

giiip HS ciing cd bai

- Cdng thiic cua amino axit cd nhdm

NH2 va nhdm COOH

- Amino axit cd tinh chat ludng tinh,

tinh axit bazo

- Khai niem ve phan iing trimg ngung

- Lfng dung quan trgng ciia amino axit

ddi vdi con ngudi

Bai tap ve nha: 1, 2,3, 4, 5, 6 (SGK)

HS he thdng lai kien thiic da hgc

D HU'ONG D A N GIAI BAI TAP SGK

-> Cdng thiic don gian: C3H7NO2

Cdng thiic phan tir: C3H7NO2

Cdng thirc cdu tao H 2 N - C H - C O O H alanin

CH3

4 Viet phuang trinh hda hgc

a) CH3 - CH - COOH + NaOH -> CH3 - CH - COONa + H 2O

NH2 NH2

b) 2CH3 - CH - NH2 + H2SO4 -)• |CH3 - CH - NH3^ /^ - - SO4

HCl bao h6a c)CH3-CH-COOH + CH30H "^'°^°"°^ CH3-CH-COOCH3 + H2O

NH2 ^ NH2

5 Viet cac phuang trinh hda hgc cua phan iing triing ngung

nH2N - [CH2]e - COOH '^"^"^""g > [ HN^CH2)6-CO ]„ + ft-H20

-^ Cdng thuc dan gian: C3H7O2N

Cdng thii'c phan tir: (C3H702N)n

M(c\,H,o,N)„ = 89 (g/mol) ^ n = 1 Vay cdng thiic phan tir la C3H7O2N

Cdng thirc cau tao: O

H2N - CH2 - C - O - CH3 (A) H2N - CH2 - COOH (B)

151

Bai 11 PEPTIT VA PROTEIN

A MUC TIEU B A I HOC

1 Kiln thu'c

HS biit:

• Peptit, protein, enzim, axit nucleic la gi va vai trd ciia chiing trong co the sinh vat

• Sa luge ve cau true va tinh chat ciia protein

HS hiiu: Tinh chdt ciia lien kit peptit kem ben trong mdi trudng axit hay bazo

2 KT nang

• Nhan dang mach peptit

• Ggi ten peptit

• Viet cac phuang trinh hda hgc ciia protit va protein

• Giai cac bai tap hda hgc phan peptit protein

3 Tinh cam, thai do

Qua ndi dung bai, HS thdy khoa hgc cd the kham pha dugc nhiing hgp chat cau tao nen ca the sdng va the gidi xung quanh, ciing cd cho HS niem tin vao khoa hgc

B C H U A N B! C U A GV VA HS

• GV: - May tinh, may chieu, cac phieu hgc tap

- He thdng cau hdi cho bai day

- Hinh ve, tranh anh lien quan den bai hgc

• HS: On tap kien thirc li thuyet, phuang phap giai bai tap ve (amino axit)

va xem trudc bai (peptit va protein)

C TI^N T R I N H DAY- HOC

Hogt dpng I

KIEM TRA BAI CU

GV chieu ndi dung bai tap lea man

hinh yeu cau 2 HS len bang trinh bay

HS chudn bi bai

HS

CsH704NNa2 + CH4O + C2H6O

Biet C5H704NNa2 cd mach cacbon

khdng phan nhanh, cd -NH2 tai

C" thi C8H1SO4N cd sd cdng thiic cau

tao phu hgp la

A 1 B 2 C 3 D 4

'<>

HS2: Cho 0,01 mol amino axit A tac

dung vira du vdi 100 ml dung dich

HCl 0,2M Cd can dung dich sau phan

ling dugc 2,18 gam mudi Khdi lugng

mol cua A la

A 109 gam B 218 gam

C 147 gam D 145gam

GV nhan xet bai lam cua 2 HS va

chuyen tiep bai: protein la thanh phan

chinh cua ca the ddng vat la co sd ciia

sir sdng Protit dugc cau tao bdi cac

chuoi polipeptit vay chiing cd cau tao

nhu till nao ta se nghien ciiu trong bai

sau

Hogt dpng cua HS

HSl len bang trinh bay:

C5H704NNa2 cd mach C khdng phan nhanh, nhdm -NH2 tai vi tri a Vay cdng thirc cau tao la

NH2 Chgn dap an B

HS2 nhan xet:

0,0Imol amino axit tac dung vira dii 0,02 mol HCl tao ra 0,01 mol mudi => amino axit cd hai nhdm NH2

Mmu6i= - ^ = 2 1 8 vay

Maminoaxit = 2 1 8 - 3 6 , 5 2 = 145 Chgn dap an D

Hogt dpng cua GV Hogt dpng cua HS

- Khai niem peptit

- Khai niem lien ket peptit

GV chieu cdng thirc sau len man hinh

yeu cau HS chi ra dau la lien kit

GV thdng bao cho HS: phan tir peptit

hgp thanh tir cac a-amino axit bdng

lien ket peptit theo mgt trat tu nhdt

dinh

- Amino axit dau N cdn nhdm NH2

- Amino axit dau C cdn nhdm COOH

Yeu cau HS chi ra amino axit ddu N,

dau C trong cac peptit sau day:

HS nghien cim SGK va nhan xet:

- Pepth la loai hgp chat chiia tir 2-50 gdc a-amino axit lien ket vdi nhau bang lien ket peptit

Lien ket peptit la lien ket C O N H giira hai don vi a-amino axit Nhdm

C O N H giiia hai don vi a amino axit ggi la nhdm peptit

HS quan sat, thao luan va nhan xet

Lien ket peptit

N H C H C O N H R'

-HS lang nghe

R^

CO-NH-'-CH2CH-CO- R^

HS quan sat thao luan va nhan xet Amino axit dSu N Amino axit dAu C NH2- C H - C O - N H - C H - C O O H

Hogt dpng cua GV

GV gidi thieu: phan tir peptit chiia

2,3,4 a-amino axit dugc ggi la di-,

tri-, tetra peptit nhiing phan tir peptit

cd nhieu hon 10 a-amino axit ggi la

polipeptit

GV yeu cau HS viet cdng thiic va ggi

ten thudng mdt sd a-amino axit don

gian

GV thdng bao ngudi ta thudng bieu

dien cau"tao cac peptit bang each ghep

tir ten viet tat cac a-amino axit theo

trat tu ciia chung Yeu cau HS cho vi

HS lang nghe, ghi bai

HS viet cdng thirc va ggi ten amino axit CH2-COOH CH3-CH-COOH NH2 NH2 Glyxin Alanin NH2-[CH2]4CH-COOH Lysin

NH2

HS neu vi du: Ala-Gly, Gly-Ala-Lys

Hogt dpng 3

2 TINH C H A T H O A HOC

GV thdng bao cho HS peptit cd hai

phan ling dac trung la phan iing thiiy

phan va phan iing mau biure

GV cho HS nghien cim SGK va yeu

cau HS viet phuong trinh hda hgc

thuy phan cac peptit sau:

Hogt dpng cda GV Hogt dpng cda HS

GV bd sung:

- Ngoai ra peptit cdn bi thuy phan khi

cd enzim xuc tac

- Khi thiiy phan peptit thudng cho

nhieu san pham nhu: amino axit, di

peptit, tri peptit,

GV lam thi nghiem:

Cho 1 - 2 ml dung dich peptit vao dng

nghiem dung Cu(OH)2 mdi dieu che

sau dd lac nhe Yeu cau HS quan sat,

neu hien tugng, giai thich

GV hudng dan HS nghien ciiu SGK

de giai thich hien tugng

GV bd sung: phan img nay ggi la phan

ling mau biure, dugc dimg de nhan

biet hgp chat cd 2 lien ket peptit trd

len

NH2-CH-CO-NH-CH-CONH-CH R- R^ R^

l-COOH + + 2H2O H* hoac OH"

NH2CHCOOH + NH2CHCOOH

+ NH2CHCOOH

HS quan sat va nhan xet

Hien tugng: Cu(OH)2 tan cho dung dich

mau tim dac trung

Gidi thich: Do pepth cd nhdm

- C O - N H - phan ung vdi Cu(0H)2 cho hgp chat mau tim dac trung

- Khai niem protein

- Cach phan loai protein

HS cho HS nghien ciiu SGK va nhan xet:

- Protein la nhung polipeptit cao phan tir

cd khdi lugng tir vai chuc nghin den vai trieu

- Protein dugc phan lam 2 loai

+ Protein don gian la protein dude cau

Hogt dpng cda GV Hogt dpng cua HS

tao tir cac a-amino axit nhu: abuinin ciia Idng trang tning, fibroin cua ta tam + Protein phirc tap la protein dugc tao thanh tir protein don gian vdi cac thanh phan ''phi protein" Nhu nucleoprotein lipoprotein

2 CAu TAO P H A N TU"

GV cho HS nghien cim SGK va yeu

cau HS nhan xet ve cau tao cua

protein

GV chilu hinh 3.4 SGK cho HS quan

sat ve cau tao cua phan tir insulin

(hoac cho HS quan sat true tiep SGK)

HS nghien ciiu SGK va nhan xet

Protein cd cau tao tuong tu peptit (nhieu lien ket peptit) nhung phiic tap hon nhieu Thudng cau tao tir 50 gdc a-amino axit trd len

Hogt dpng 5

3.TiNHCHAT

a) Tinh chat vat li

GV lam thi nghiem: Diing dng nhd

gigt cho vao dng nghiem 1 ml Idng

trang tning, sau dd cho them 2-3 ml

nude cat, lac nhe dng nghiem Dun sdi

dng nghiem tren den cdn

Yeu cau HS nhan xet ve tinh chat vat

li cua protein

GV giai thich hien tugng protein ddng

tu la do cdu tnic ciia protein bi thay

ddi khi dun ndng

HS quan sat va nhan xet:

Protein tan trong nude tao thanh dung dich keo

Khi dun ndng Idng trang tning bi ddng

tu

b) Tinh chdt hoa hgc

GV yeu cdu HS du doan tinh chat hda

hgc ciia protein

HS thao luan va nhan xet

Protein cd cau tao tuong tu peptit nen cd cac phan iing

Hogt dpng cua GV Hogt dpng cua HS

- Phan ling thiiy phan khi cd xiic tac

• axit, baza, enzim

Phan ling mau biure

GV nhan xet va bd sung:

- Phan img mau biure diing de nhan

biet protein

- Protein cd phan img vdi dung dich

HNO3 dac cho ket tiia mau vang (dd la

phan irng nitro hda vao vdng benzen

cd trong gdc amino axit)

4 VAI TRO CUA PROTEIN DOI v O l SU SONG

HS nghien ciiu SGK va nhan xet

- Protein tao.ra nhan te bao va nguyen

GV cho HS nghien ciiu SGK tir dd

neu tam quan trgng cua protein ddi

vdi sir sdng sinh chdt la thanh phan chinh ciia te bao

vay protein la ca sd tao nen sir sdng, co protein mdi cd sir sdng

- Protein la thiic an quan trgng vi nd bo sung protein cho ca the, mdt phan khac bxi hda cung cap nang lugng cho hoat dgng ciia ca the

Hogt dpng 6

III K H A I N I E M V E E N Z I M V A A X I T NUCLEIC

1 ENZIM

a) Khdi niim

GV cho HS nghien ciiu SGK tir dd

neu khai niem enzim

HS nghien ciiu SGK va nhan xet

Enzim la nhung chat hau bet cd ban chat

protein, cd kha nang xiic tac cho cac qua trinh hda hgc, dac biet trong co the sinh vat

Hogt dpng cua GV

b) Dgc diim xiic tdc cda enzim

GV gidi thieu cho HS biet dac diem

xiic tac ciia enzim

- Hoat ddng xuc tac cua enzim cd tinh

chgn lgc rat cao (mdi enzim chi xuc

tac cho mdt chuyen hda nhat dinh)

- Tdc do phan iing nhd xuc tac enzim

rat Idn (thudng gap lO^-lO" lan xiic

tac hda hgc)

Hogt

2 AXIT

a) Khdi niim

GV ggi mdt HS dgc phan khai niem

axit nucleic trong SGK

GV tdm tat khai niem axit nucleic:

- Axit nucleic la polieste cua axit

photphoric va pentozo (mono saccarit

cd 5 C) mdi pentozo lai lien ket vdi 1

nguyen tir N tao thanh cac hgp chat di

vdng (ki hieu la A, X, G, T, U)

- Axit nucleic la thanh phan quan

trgng nhdt ciia nhan te bao

- Axit nucleic la polime cd tinh axit

- Axit nucleic cd 2 dang la: ADN va

Vi du: enzim amilaza

HS lang nghe va ghi bai

dpng 7

NUCLEIC

HS dgc phan khai niem axit nucleic cac

HS khac lang nghe

Hogt dpng cda GV Hogt dpng cda HS

tdm tat vai trd cua axit nucleic

HSl dgc phdn vai trd ciia axit nucleic

trong SGK

HS2 trinh bay vai trd cua axit nucleic:

- Tdng hgp protein, sir chuyen cac thdng tin di truyen

- AND chira cac thdng tin di truyen, ma hda cho boat ddng sinh trudng va phat trien cua co the sdng

- ARN tham gia vao qua trinh giai ma thdng tin di truyen

Hogt dpng 8

CUNG CO B A I - B A I T A P V E N H A

GV phat cac phieu hgc tap de HS tra

ldi ciing cd kien thirc da hgc:

Phieu I De tdng hgp cac protein tir

cac amino axit, ngudi ta diing phan

img:

A Triing hgp B Triing ngung

C Trung boa D Este hoa

Phieu 2 Cho polime

-f NH-(CH2)5-CO ]n tac dung vdi dung

dich NaOH trong dieu kien thich hgp

San pham thu dugc la

Hogt dpng cda GV

Phieu 3 Thuy phan mdt doan peptit

dugc tao ra tir cac a-amino axit A,

B,C,

D, E cd cdu tao la ADCBE Hdi thu

dugc tdi da bao nhieu hgp chat cd lien

ket peptit?

A 4 B 5 C 8 D 9

Phieu 4 Sd lugng dipeptit cd the tao

thanh tir hai amino axit alanin va

Bai tap ve nha: 1, 2, 3, 4, 5, 6 (SGK)

D HU'ONG D A N GIAI BAI TAP SGK

\ Hgp chat thudc loai dipeptit: chgn dap an B

2 Cho Cu(0H)2 d nhiet do thudng thi etanol khdng hien tugng, Idng trang triing cho phiic mau tim (phan iing mau biure), glucoza va glixerol cho phiic mau cua ancol da chiic vdi Cu(0H)2

Cho Cu(0H)2 trong mdi trudng kiem dun ndng chat cho ket tiia dd gach la glucoza cdn lai la glixerol

3 Viet cdng thiic cau tao va ggi ten cac tripeptit cd the hinh thanh tir glyxin, alanin, phenylalanin

H2N-CH2-COOH CH3-CH-COOH C6HS-CH2-CH-COOH

NH2 H2N-CH2-CO-NH-CH-CO-NH-CH-COOH

CH3 CH2-CeHs CH3-CH-CO-NH-CH2-CO-NH-CH-COOH

H2N-CH2-CO-NH-CH-CO-NH-CH-COOH Gly-Phe -Ala

CH2-CeHs CH3 H2N-CH-CO-NH-CH2-CO-NH-CH-COOH Phe-Gly-Ala CH2-C6H5 CH3

H2N-CH-CO-NH-CH-CO-NH-CH2-COOH Phe -Ala -Gly

6 Uaianin cd trong 500 g A = — = 1,91 (mol)

Khdi luong alanin trong 1 mol A la: '• = 17000 (g)

• ^ ^ 500

naiaiiin CO trong 1 mol A = = 191 (mol) Sd mat xich alanin

= naianin= 191 (mat xi'ch)

E TU" LIEU THAM K H A O

Phuong phap xac dinh trat tu sap xep cac gdc amino axit trong mach peptit:

1 Xac dinh amino axit " dau N"

a) Phuang phdp Sanger (Anh, 1958)

Cho peptit tac dung vdi 2,4-dinitro florobenzen, nhdm amino cua amino axit

"dau N" sau khi phan irng tao thanh dan xuat 2,4-dinitrophenyl ciia peptit, dem thiiy phan trong dung dich axit, thu dugc hdn hgp cac amino axit va dan xuat 2,4-dinitrophenyl ciia amino axit "dau N" Diing phuang phap sac ki de nhan biet, tir dd suy ra gdc amino axit "dau N"

0 2 N - { 0 / '^ "^ / Ri R2

H2N-CH-CO-NH-qH-CO-HF

Ri R2 NO2

02l^^O)-«N-C]H-CO-NH-CjH-CO- " " " ^ ^ f "^^

) Ri R2 NO2

" 0 2 > H O ^ N - C j H - C 0 0 H +

H3N-CfH-COO-r ^ R, R2

NO2 Axit N-(2,4-dinitrophenyl) amino

b) Phuong phdp Edman (Thuy Diin, 1950)

Theo phuang phap nay, ngudi ta cho peptit tac dung vdi phenyl isothioxianat (CeH5N=C=S), nhdm amino ciia gdc amino axit "dau N" sau phan img thu dugc dan xuat phenyl isothiocacbamoyl peptit Sau dd cho dan xuat nay tac dung vdi HCl trong dung mdi nitrometan se thu dugc san pham do su phan cat lien ket pettit d sau gdc amino axit "dau N" tao thanh phenyl thiohidantoin va peptit ngan hon Tach lay amino axit va phan tich bang phuong phap sac ki

CeHs-N=C=S + H2N-CH-CO-NH-CH-CO-NH-CH-CO >

Ri R2 R3 Phenyl isothioxinat peptit

-^ CeHj-NH-C-HN-CH-CO-NH-CH-CO-NH-CH-CO- CH'SO, '

S R, R2 R3 Phenyl isothiocacbamoyl

San phdm phenyl thiohidantoin dugc nhan biet bang phuang phap sac ki Phuong phap nay da phan tich dugc nhieu peptit nhu mioglobin cd tdi 60 amino axit

c) Phuong phdp thdy phdn khong hodn todn bdng enzim aminopeptitdaza

Enzim aminopeptitdaza xiic tac cho phan iing thiiy phan tao ra amino axit

"dau N" va phan tir peptit nhd hon

2 Xac djnh amino axit "duoi C"

Phuong phap nay dua tren su thuy phan peptit nhd chat xuc tac la enzim

cacboxipeptitdaza Day la loai enzim xiic tac, phan cdt chgn lgc lien ket amit

ciia amino axit cudi ciing cd nhdm COO" tu do

Amino axit thu dugc dem phan tich bang phuong phap sac ki Aminoaxit nay

chinh la amino axit "dudi C" Tuy nhien phuang phap nay cdn de lai ban che

la enzim cacboxipeptitdaza khdng tach dugc amino axit "dudi C"cua prolin ra

khdi mach peptit

3 ThQy phan tiJmg phan mach peptit

De tao thanh timg doan peptit ngan, ngudi ta thudng dimg cac enzim tripsin,

chimotripsin va pepsin de xiic tac cho sir phan cat peptit d nhiing vi tri xac

dinh Chang ban, enzim tripsin phan cat lien ket khi nhdm cacboxyl la cua

lysin hay argimin, cdn enzim chimotripsin xiic tac thuy phan phenylalanin,

tryptophan, tyrosin, leuxin, axit aspactic va axit glutamic, nghTa la loai enzim

pepsin phan cat cd tinh chgn lgc kem hon Dem phan tich cac doan peptit

ngan bang phuong phap sac ki, rdi sau dd xac dinh trat tu sap xep cac goc

amino axit trong mdi doan peptit dd theo cac phuong phap trinh bay d tren

Ngoai ra cd the diing bromxian (BrCN) de phan cat mach peptit d sau gdc

Nhu vay, neu dung xiic tac khac nhau de phan cat mat se thu dugc nhiing

doan peptit khac nhau

Khi biet dugc trat tu sap xep cua cac gdc amino axit trong timg doan peptit

ngan, ta cd the thiet lap dugc toan bd phan tir peptit

Bai 12 LUYEN TAP:

CAU TAO VA TINH CHAT CUA AMIN, AMINO AXIT VA PROTEIN

A MUC TIEU B A I HOC

1 Kl§n thiFC

HS cung cd kiin thicc vi:

• Cdng thiic cau tao tdng quat va tinh chat hda hgc co ban ciia amin, amino

axit, protein

• Cac each ggi ten, viet ddng phan ciia amin, amino axit

• So sanh, cimg cd kien thirc ve cau tao va tinh chat ciia amin, amino axit,

protein

2 KT nang

• Giai thanh thao bai tap ve amin, amino axit, protein

• Lap bang tdng ket cac chuong

• Vilt cac phuong trinh hda hgc tdng quat cho cac hgp chat: Amin, amino

axit, protein

• Vilt phuong trinh hda hgc dl giai thich tinh chat cua amin, amino axit,

protein

3 Thai do, tinh cam

HS ndm dugc tam quan trgng cua cac hgp chat: amin, amino axit va protein

cimg vdi tam kien thirc ve amin, amino axit va protein dugc hieu kT (cau tao va

tinh chat cua hgp chat ) se tao himg thii cho HS khi hgc bai luyen tap nay

B CHUAN B! CUA GV VA HS

• GV - May tinh, may chieu

- He thdng bai tap dn tap, bang he thdng tinh chat hda hgc cua am.in, amino axit, protein

• HS On tap amin, amino axit, protein va xem trudc bai luyen tap

C T I ^ N TRiNH DAY- HOC

Hogt dpng cua GV

GV chia HS thanh 4 - 5 nhdm va giao

cac ndi dung luyen tap cho HS

Tinh chdt hda hoc

+ Phan ung biure

HS nhdm 1 thao luan dudi sir hudng dan, dieu khien ciia GV cho ket qua

^ ^ - ^ ^ Chdt

Vdn de ^ ^ - \ , ^

Cong thiic chung

Amin bdc mdt Ankyl amin

-CO the phan iing vdi HCl tao muoi

-Quy hoa xanh

-Tao muoi theo phan iing:

CeH5NH2+ HCl -^ CeH5NH3CI

Khong tac • dung voi ROH nhung CO the phan iing vdi HCl tao muoi

-Phan ling tao ket tiia C6HsNH2 + 3Br2 ^ •

HBr + CeH2Br3NH2 i

- -

-Quy khong doi mau