Sequence of amino acids in a polypeptide chain of protein molecule coresponds to the sequence of nucleotides on mRNA for that pr
otein. If reading frame of mRNA for a human protein is 993 nucleotide including a stop codon at the end, how many amino acids would be incorporated in the polypeptide chain?
A codon is the sequence of three nucleotides on mRNA that refers for particular amino acid during translation (protein synthesis) process. The four nucleotides arrange themselves in various combinations to produce different codons. The tRNA with corresponding anticodon attach the particular amino acid to polypeptide chain during translation.
Remember there is always a stop (UAA) and start codon (AUG) for the synthesis of polypeptide and stop codon does not contribute for any amino acid. It just terminate the polypeptide chain synthesis. We know that a codon is made up of three nucleotide so our calculation will be.
993-stop codon =990
990/3=330
So that's why 330 amino acid will be incorporated in the polypeptide chain.
Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are structures within cells that contain a person's genes. Genes are contained in chromosomes, which are in the cell nucleus.
RNA polymerase binds to the lac promoter and begins transcribing
the stretch of DNA to messenger RNA.
Therefore, in other words, the stretch of DNA is expressed. The DNA sequence of
the lac promoter 'signals' where the RNA
polymerase will bind and where transcription
will begin. Promoters are found upstream of a gene to be transcribed.
