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
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.
The nucleotide T always pairs with
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.
To determine the resulting amino acid sequence after transcription and translation, we need to follow the central dogma of molecular biology. The first step is transcription, where the DNA sequence is converted into mRNA. During transcription, the DNA strand is used as a template to synthesize an mRNA molecule.
In the given DNA sequence TAC TTG ACC, the complementary RNA sequence produced during transcription would be AUG AAC UGG.
Next, we move on to translation, where the mRNA sequence is used as a template to generate an amino acid sequence. In translation, a group of three nucleotides on the mRNA, known as a codon, is read by a ribosome, and a corresponding amino acid is added to the growing polypeptide chain.
Using a genetic code chart or table, we can look up the codons and identify the corresponding amino acids. Here is a breakdown of the codons in the mRNA sequence and their corresponding amino acids:
AUG - Methionine (Met)
AAC - Asparagine (Asn)
UGG - Tryptophan (Trp)
Therefore, the resulting amino acid sequence after transcription and translation would be "Met-Asn-Trp" (option a).