Question

If the DNA sequence is TAC TTG ACC, what would be the resulting amino acid sequence after transcription and translation?

(Hint: Think of the first step of protein synthesis? Do this first and then find the amino acid sequence.)



a
Met-Asn-Trp
b
Tyr-Leu-Thre
c
Isol-Lys-STOP
d
Gly-Ala-Val

Answer 1

The nucleotide T always pairs with

Answer 2

The first step in protein synthesis is transcription, where the DNA sequence is transcribed into mRNA.

The DNA sequence given is:
TAC TTG ACC

During transcription, the DNA sequence is used to create a complementary mRNA sequence. The base pairing rules for this process are such that adenine (A) pairs with uracil (U) (since thymine (T) is replaced by uracil in RNA), and cytosine (C) pairs with guanine (G), while guanine (G) pairs with cytosine (C).

So, the mRNA sequence transcribed from the DNA sequence would be:
AUG AAC UGG

Now, during translation, this mRNA sequence is translated into an amino acid sequence. The mRNA codon AUG codes for the amino acid methionine (Met), AAC codes for asparagine (Asn), and UGG codes for tryptophan (Trp).

Therefore, the resulting amino acid sequence after transcription and translation would be:
Met-Asn-Trp

This corresponds to option (a) Met-Asn-Trp.

Answer 3

In DNA, the nucleotide thymine (T) always pairs with the nucleotide adenine (A) through the formation of two hydrogen bonds. This is due to the specific base pairing rules defined by the complementary nature of the DNA structure, often referred to as the base pairing rule or Chargaff's rule.