Genetic Coding: mRNA and Polypeptides

How do mRNA and polypeptides relate to each other in genetic coding?

A certain gene in a bacterium codes for a polypeptide that is 400 amino acids long. How many nucleotides are needed in the mRNA to code for this polypeptide?

Answer:

The number of nucleotides needed in the mRNA to code for a 400 amino acid polypeptide is 1200 nucleotides.

The length of a polypeptide is determined by the number of amino acids it contains. In the case of a polypeptide that is 400 amino acids long, the mRNA requires 1200 nucleotides to code for it.

Each amino acid is represented by a three-nucleotide sequence known as a codon in the mRNA. Since the polypeptide consists of 400 amino acids, there will be a need for 400 codons in the mRNA. By multiplying 400 codons by 3 nucleotides per codon, we arrive at the total of 1200 nucleotides needed to code for the polypeptide.

Nucleotides are essential components in genetic coding processes. They provide chemical energy and play crucial roles in various cellular functions such as amino acid synthesis, protein synthesis, cell division, and cell signaling.

Furthermore, nucleotides are vital for enzymatic reactions as they are incorporated into important cofactors like coenzyme A, FAD, FMN, NAD, and NADP+. Understanding the relationship between mRNA, polypeptides, and nucleotides is fundamental in grasping the intricacies of genetic coding and its role in cellular processes.