_____________________________ 232. DNK ning zanjirida 960 ta guanin nukleotidi bo‘lib umumiy
nukleotidlarning 40% ini tashkil etadi. Undagi gen asosida
sintezlangan oqsildagi peptid bog’lari sonini toping.
A) 390 B) 400 C) 398 D) 399 Ishlanishi: 1) G-960------40%
A-x----10% A-x=(960*10)/40=240
2) A+G=960+240=1200N
3) 1200N/3=400AK
4) Peptid=AK-1 Peptid=400-1=399P Javob: D _____________________________ 233. Oqsil molekulasida 41 ta peptid bog’i bor. Ushbu DNK
bo‘lagi asosida sintezlangan oqsildagi aminokislotalar sonini
aniqlang.
A) 40 ta B) 41 ta C) 43 ta D) 42 ta Ishlanishi: 1) AK=Peptid+1 AK=41+1=42 AK Javob: D _____________________________ 234. iRNK molekulasida A-20%, C-30%, U-40% bo’lsa, teskari
transkripsiya jarayonida sintezlangan DNK qo‘sh zanjiridagi
sitozinning foizini ko‘rsating.
A) 10 B) 30 C) 20 D) 40 Ishlanishi: 1) i-RNK da: A-20%; G-10%; U-40%; S-?
S=100-(A+G+U)=100-(20+10+40)=100-70=30%-S
2) DNK da A(T)=(U+A)/2 A(T)=(20+40)/2=30%A(T) G(S)=(G+S)/2 G(S)=(10+30)/2=20%G(S) Javob: C _____________________________ 235.
AUGCGAAUCCGACGGCUU
nukleotidlar
ketma-
ketligiga ega i-RNK molekulasiga komplementar DNK qo‘sh
zanjiridagi nukleotidlar orasidagi fosfodiefir bog’lar sonini (a), A, G,
C, T nukleotidlar sonini (b) va ular orasidagi vodorod bog’lar sonini
(c) aniqlang. Polinukleotid zanjiridagi nukleotidlar o‘zaro fosfodiefir
bog’lari orqali bog’langan.
A) a-36; b-A va T 20 ta, G va C 8 ta; c-44
B) a-17; b-A va T 8 ta, G va C 10 ta; c-46
C) a-34; b-A va T 16 ta, G va C 20 ta; c-46 D) a-36; b-A va T 8 ta, G va C 10 ta; c-46
Ishlanishi: 1) i-RNK da: AUGSGAAUSSGASGGSUU
DNK 1-ipda: TA
SGST TAGGSTGSS
GAA
i-RNK da: ATGSGAAT
S
SGASGGSTT
2) 1 ta ipda: A+T=16N; G+S=20N
3) F=2N-2 F=36-2=34F 4) H=2A+3G H=2*8+3*10=16+30=46H Javob: C