Insulin is synthesized as preproinsulin, which has 81 amino acids. How many heterocyclic bases must be present in the informational DNA strand to code for preproinsulin (assuming no introns are present)?

Verified step by step guidance

1. Understand that each amino acid in a protein is coded by a sequence of three nucleotides, known as a codon, in the DNA.
2. Recognize that preproinsulin consists of 81 amino acids.
3. Calculate the total number of nucleotides required by multiplying the number of amino acids (81) by the number of nucleotides per codon (3).
4. Acknowledge that the informational DNA strand must contain this number of nucleotides to code for the preproinsulin protein.
5. Conclude that the number of heterocyclic bases in the DNA strand is equal to the total number of nucleotides calculated.

Key Concepts

Amino Acids and Codons

Amino acids are the building blocks of proteins, and each amino acid is encoded by a sequence of three nucleotides known as a codon. In the case of preproinsulin, which consists of 81 amino acids, the total number of codons required for its synthesis is 81, as each amino acid corresponds to one codon.

DNA and Nucleotides

DNA is composed of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base. The four types of nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). Each codon in the DNA sequence is formed by a specific arrangement of these bases, and since each codon consists of three bases, the total number of bases needed can be calculated based on the number of codons.

Transcription and Translation

Transcription is the process by which the DNA sequence is copied into messenger RNA (mRNA), which then undergoes translation to synthesize proteins. In this context, the informational DNA strand must be transcribed to produce mRNA that contains the codons for the 81 amino acids of preproinsulin, ensuring that the correct sequence of bases is present to code for the protein.