The α chain of eukaryotic hemoglobin is composed of 141 amino acids. What is the minimum number of nucleotides in an mRNA coding for this polypeptide chain?

Verified step by step guidance

1. Understand that each amino acid in a polypeptide is encoded by a codon, which is a sequence of three nucleotides in mRNA.
2. Calculate the total number of codons needed by multiplying the number of amino acids (141) by the number of nucleotides per codon (3).
3. Recognize that the mRNA must also include a start codon, which is typically AUG, adding three more nucleotides to the total count.
4. Consider that the mRNA may also include a stop codon, which signals the end of translation, adding another three nucleotides.
5. Sum the total number of nucleotides from the codons, start codon, and stop codon to find the minimum number of nucleotides in the mRNA.

Key Concepts

Genetic Code

The genetic code is a set of rules that defines how the sequence of nucleotides in DNA and mRNA is translated into the sequence of amino acids in proteins. Each amino acid is encoded by a sequence of three nucleotides, known as a codon. Understanding this code is essential for determining how many nucleotides are required to code for a specific number of amino acids.

Amino Acids and Codons

Amino acids are the building blocks of proteins, and each amino acid is specified by a codon, which consists of three nucleotides. Therefore, to calculate the number of nucleotides needed for a polypeptide chain, one must multiply the number of amino acids by three. This relationship is fundamental in molecular biology and genetics.

mRNA Synthesis

mRNA synthesis is the process by which messenger RNA is created from a DNA template during transcription. The mRNA serves as a copy of the genetic information needed to produce proteins. Understanding mRNA synthesis is crucial for determining how the nucleotide sequence corresponds to the amino acid sequence in proteins.