Genética, Citologia e Bioquímica ⇒ Código Genético Tópico resolvido

[Holanda1427]

(UFSM 2013) Ao percorrerem uma trilha ecológica, os escoteiros encontraram duas plantas que eram fenotipicamente idênticas, porém tinham aromas distintos, uma exalava citral, outra canela. Com permissão do fiscal, levaram amostras para análise de DNA. A seguir, tem-se parte das sequências obtidas das plantas.

Capturar 14.PNG (120.52 KiB) Exibido 4033 vezes

Com base nessas informações, determinou-se que as plantas citral e canela são diferentes genotipicamente. Os aminoácidos correspondentes a elas são, respectivamente:

a)leu–fen–gli–trp–ser–cis–ala–fen e pro–fen–pro–gli–fen–gli–fen–pro.
b)asn–lis–pro–tre–tre–pro–arg–lis e gli–lis–gli–pro–lis–pro–lis–gli.
c)asn–lis–pro–tre–tre–pro–arg–lis e pro–fen–pro–gli–fen–gli–fen–pro.
d)leu–lis–gli–tre–ser–pro–ala–lis e pro–lis–pro–pro–fen–pro–pro–gli.
e)leu–fen–gli–trp–ser–cis–ala–fen e gli–lis–gli–pro–lis–pro–lis–gli.

Resposta

---

a

[MateusQqMD]

Olá,

Em primeiro lugar, faz-se necessário realizar o processo de tradução dos segmentos de DNA apresentados:

[tex3]\begin{array}{ccccccccc}
\text{citral..} &- & \text{A} & \text{A} & \text{C} & \text{A} & \text{A} & \text{G} & \text{C} & \text{C} & \text{A} & \text{A} & \text{C} & \text{C} & \text{A} & \text{G} & \text{C} & \text{A} & \text{C} & \text{G} & \text{C} & \text{G} & \text{G} & \text{A} & \text{A} & \text{A}& -& \\
& {\color{red}-} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}}& {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}}& {\color{red}-} &
\end{array}[/tex3]

Código: Selecionar tudoSHIFT+Click na eq = ZOOM

[tex3]\begin{array}{ccccccccc}
\text{citral..} &- & \text{A} & \text{A} & \text{C} & \text{A} & \text{A} & \text{G} & \text{C} & \text{C} & \text{A} & \text{A} & \text{C} & \text{C} & \text{A} & \text{G} & \text{C} & \text{A} & \text{C} & \text{G} & \text{C} & \text{G} & \text{G} & \text{A} & \text{A} & \text{A}& -& \\
& {\color{red}-} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}}& {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{C}} & {\color{red}\text{G}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}}& {\color{red}-} &
\end{array}[/tex3]

De acordo com a tabela essa sequência corresponde aos seguintes aminoácidos: Leu-Phe-Gly-Trp-Ser-Cys-Ala-Phe

[tex3]\begin{array}{ccccccccc}
\text{canela..} &- & \text{G} & \text{G} & \text{G} & \text{A} & \text{A} & \text{A} & \text{G} & \text{G} & \text{A} & \text{C} & \text{C} & \text{A} & \text{A} & \text{A} & \text{A} & \text{C} & \text{C} & \text{A} & \text{A} & \text{A} & \text{A} & \text{G} & \text{G} & \text{C}& -& \\
& {\color{red}-} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}}& {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{G}}& {\color{red}-} &
\end{array}[/tex3]

Código: Selecionar tudoSHIFT+Click na eq = ZOOM

[tex3]\begin{array}{ccccccccc}
\text{canela..} &- & \text{G} & \text{G} & \text{G} & \text{A} & \text{A} & \text{A} & \text{G} & \text{G} & \text{A} & \text{C} & \text{C} & \text{A} & \text{A} & \text{A} & \text{A} & \text{C} & \text{C} & \text{A} & \text{A} & \text{A} & \text{A} & \text{G} & \text{G} & \text{C}& -& \\
& {\color{red}-} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}}& {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{G}} & {\color{red}\text{G}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{U}} & {\color{red}\text{C}} & {\color{red}\text{C}} & {\color{red}\text{G}}& {\color{red}-} &
\end{array}[/tex3]

De acordo com a tabela essa sequência corresponde aos seguintes aminoácidos: Pro-Phe-Pro-Gly-Phe-Gly-Phe-Pro

Portanto, a resposta é a letra A.

[Holanda1427]

Mas, só uma última dúvida. Porque se torna necessário realizar a tradução?

[MateusQqMD]

Sem problemas. O DNA constituinte dos genes não atua diretamente na síntese das proteínas, mas por meio de moléculas de RNA. As instruções codificadas nas sequências de bases nitrogenadas do DNA constituinte dos genes formam os aminoácidos a partir de um conjunto de 3 nucleotídeos. Por isso é necessário realizar a tradução.

[Holanda1427]

Entendi tudo agora, muito obrigado meu caro

[MateusQqMD]

De nada =)

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