Task

An enzyme in a bacterial cell has a molecular mass of 44,000 Da. It consists of one polypeptide chain and is encoded by an intron-free gene (the coding part includes the stop codon). Mean amino-acid mass is 110 Da, nucleotide mass 345 Da, and the distance between adjacent nucleotides 0.34 nm (ignore water loss). 1) Describe the relationship between gene, genetic code and protein structure (one gene — one polypeptide, triplet code, stop codon). 2) Describe the method: going from protein mass to the number of amino acids, then to the number of nucleotides in mRNA and the gene. 3) Find the number of amino acids in the protein and the number of nucleotides in the coding part of the mRNA. 4) Calculate the number of nucleotides and the length (nm) of the gene (double-stranded DNA). 5) Find the mass of the gene and how many times it exceeds the protein mass. For each part, write out the law or method used (cross scheme, formulas, reasoning) and all calculations step by step.