How many different proteins, each with a unique amino acid sequence, can be constructed that have a length of five amino acids?

Verified step by step guidance

1. Understand that proteins are made up of amino acids linked in a sequence, and each position in the sequence can be occupied by any of the 20 standard amino acids.
2. Recognize that the problem asks for the number of unique sequences of length five, where the order of amino acids matters and repetition is allowed.
3. Use the fundamental counting principle: for each of the 5 positions, there are 20 possible amino acids that can be chosen.
4. Express the total number of unique sequences as the product of possibilities for each position, which is \$20 \times 20 \times 20 \times 20 \times 20$.
5. Write this product in exponential form as \$20^{5}$ to represent the total number of different proteins with a length of five amino acids.

Key Concepts

Amino Acid Sequence and Protein Structure

Proteins are made up of chains of amino acids linked in a specific order. The sequence of amino acids determines the protein's unique structure and function. Even a small change in the sequence can result in a different protein.

Number of Amino Acids in Nature

There are 20 standard amino acids commonly found in proteins. Each position in a protein chain can be occupied by any of these 20 amino acids, which affects the total number of possible unique sequences.

Combinatorial Calculation of Protein Variants

The total number of unique proteins of a given length is calculated by raising the number of amino acid options (20) to the power of the protein length. For a protein of length five, the number of unique sequences is 20^5.