Describe the processes of transcription and translation and correctly identify the anticodon for the following DNA template strand-ACG TGG GCA TGA ACG TGG. Which amino acids do these anticodon represent?
Transcription and translation are essential processes in gene expression, where the information encoded in DNA is converted into functional proteins.
1. Transcription: Transcription is the process by which the DNA template strand is copied to produce a complementary RNA molecule. The steps involved in transcription are as follows:
- Initiation: RNA polymerase, an enzyme, recognizes and binds to the DNA template strand at the promoter region.
- Elongation: The RNA polymerase moves along the DNA template strand in the 3' to 5' direction, synthesizing a complementary RNA molecule in the 5' to 3' direction.
- Termination: Transcription ends when the RNA polymerase reaches a terminator region, causing the detachment of the RNA molecule from the DNA template strand.
For the given DNA template strand ACG TGG GCA TGA ACG TGG, the RNA molecule produced during transcription would have the sequence UGC ACC CGU ACU UGC ACC. Here, T in DNA is replaced by U in RNA.
2. Translation: Translation is the process by which the RNA molecule synthesized during transcription is converted into a sequence of amino acids, forming a protein. The steps involved in translation are as follows:
- Initiation: The ribosome, along with the mRNA molecule, binds to the start codon AUG (methionine) on the mRNA.
- Elongation: The ribosome moves along the mRNA molecule, reading three nucleotides at a time, known as codons. Each codon specifies one amino acid. The corresponding aminoacyl-tRNA binds to the codon through complementary base pairing between the codon on mRNA and the anticodon on tRNA.
- Termination: The ribosome reaches a stop codon (UAA, UAG, or UGA) on the mRNA, causing the release of the newly synthesized protein.
To determine the anticodon for a given DNA template strand, we first need to transcribe it into an RNA molecule. For the template strand ACG TGG GCA TGA ACG TGG, the transcribed RNA molecule is UGC ACC CGU ACU UGC ACC.
Now, let's identify the anticodon sequence based on the RNA molecule using the following complementary base pairing:
- Adenine pairs with Uracil (A-U)
- Cytosine pairs with Guanine (C-G)
- Guanine pairs with Cytosine (G-C)
- Thymine (in DNA) pairs with Adenine (T-A)
The anticodons for the RNA molecule UGC ACC CGU ACU UGC ACC are ACG UGG GCA UGA ACG UGG.
The anticodons ACG, UGG, and GCA correspond to the amino acids Threonine, Tryptophan, and Alanine, respectively.
Therefore, the anticodons ACG, UGG, and GCA represent the amino acids Threonine, Tryptophan, and Alanine, respectively.