Question

What are the sequences of all the possible tripeptides that contain the amino acids aspartic acid, leucine, and phenylalanine? Use the three-letter abbreviations to express your answer.

Short answer

Asp-Leu-Phe, Asp-Phe-Leu, Leu-Asp-Phe, Leu-Phe-Asp, Phe-Asp-Leu, Phe-Leu-Asp.

Step-by-step solution

- Understand the Given Amino Acids

Identify the three given amino acids and their three-letter abbreviations: Aspartic acid (Asp), Leucine (Leu), and Phenylalanine (Phe).

- Determine the Number of Positions

A tripeptide consists of three amino acid positions. Therefore, each tripeptide will have three slots to be filled by Asp, Leu, and Phe.

- Calculate Possible Permutations

Since we need to find all possible sequences of tripeptides, we need to determine all possible permutations of the set {Asp, Leu, Phe}. The number of permutations of 3 distinct items is given by 3!, which is 6.

- List the Permutations

List all 6 permutations of the triplet Asp, Leu, and Phe:

Key concepts

amino acid

Amino acids are the building blocks of proteins. Each amino acid has a unique structure and properties that influence how proteins function. In this exercise, we are dealing with three specific amino acids: aspartic acid, leucine, and phenylalanine. Aspartic acid (Asp) is known for its acidic side chain, which can lose a proton and carry a negative charge. Leucine (Leu) is a branched-chain amino acid with a hydrophobic side chain, making it non-polar. Phenylalanine (Phe) has an aromatic side chain, which contributes to the hydrophobic nature of proteins. Understanding these unique properties is essential in biochemistry, where the sequence and properties of amino acids determine protein structure and function.

permutations

Permutations refer to the arrangement of items in a specific order. In this exercise, we aim to find all possible sequences of tripeptides formed by the amino acids Asp, Leu, and Phe. Since we are dealing with three unique amino acids, we calculate the total number of permutations using the factorial notation. For three distinct items, the number of permutations is given by 3! = 3 × 2 × 1 = 6. This means there are 6 different ways to arrange Asp, Leu, and Phe into tripeptides. Permutations are important in many fields including biochemistry, where different sequences of amino acids can produce proteins with vastly different properties and functions.

three-letter code

The three-letter code is a shorthand notation used to represent amino acids. Each amino acid has a unique three-letter abbreviation, which makes it easier to quickly identify and write sequences. For example:

• Aspartic acid is abbreviated as Asp
• Leucine is abbreviated as Leu
• Phenylalanine is abbreviated as Phe

In this problem, we use the three-letter codes to list all possible tripeptides. Using three-letter codes simplifies documentation and communication in biochemistry and other life sciences. For a tripeptide composed of Aspartic acid, Leucine, and Phenylalanine, possible sequences include Asp-Leu-Phe, Leu-Asp-Phe, etc.

biochemistry

Biochemistry is the study of the chemical processes within and related to living organisms. It is an interdisciplinary field that combines biology and chemistry. An exciting aspect of biochemistry is understanding how proteins are formed from sequences of amino acids. In this exercise, we explored how different permutations of amino acids can form various tripeptides. Each sequence of amino acids can lead to a protein with a specific structure and function. This knowledge is fundamental in areas such as genetics, molecular biology, and pharmacology. By identifying and analyzing amino acid sequences, biochemists can gain insights into the mechanisms of life at the molecular level.