which of the following determines the amino acid sequence in a protein.
Answer: Amino acid sequence in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it. The process of protein synthesis, also known as translation, involves the conversion of the information encoded in DNA into a specific amino acid sequence.
The sequence of nucleotides in the DNA molecule serves as a template for the synthesis of mRNA (messenger RNA) during transcription. The mRNA then carries the genetic information from the DNA to the ribosomes, which are the cellular machinery responsible for protein synthesis.
During translation, the ribosomes read the sequence of mRNA in groups of three nucleotides called codons. Each codon corresponds to a specific amino acid or a stop signal. The genetic code, composed of 64 codons, specifies the relationship between the sequence of nucleotides in mRNA and the sequence of amino acids in a protein.
Transfer RNA (tRNA) molecules play a crucial role in the translation process. Each tRNA molecule carries a specific amino acid and has an anticodon region that is complementary to the codon on the mRNA. As the ribosome moves along the mRNA, it matches the codons with the appropriate anticodons on the tRNA molecules, allowing the amino acids to be linked together in the correct order.
The sequential arrangement of amino acids determines the three-dimensional structure of a protein, which in turn determines its function. Even a slight change in the DNA sequence can result in a different amino acid being incorporated into the protein, leading to structural and functional alterations.
In summary, the sequence of nucleotides in the gene (DNA) is the key determinant of the amino acid sequence in a protein. This sequence is transcribed into mRNA, which is then translated into a specific sequence of amino acids, giving rise to the unique structure and function of each protein.