Amino acids are classified as positively charged, negatively charged, or electrically neutral.
Which category includes lysine?

Verified step by step guidance

1. Understand the classification of amino acids: Amino acids are categorized based on the properties of their side chains (R groups). These categories include positively charged, negatively charged, and electrically neutral amino acids.
2. Recall the structure of lysine: Lysine is an amino acid with a side chain that contains an amino group (-NH2) at the end of a long aliphatic chain.
3. Determine the charge of lysine's side chain: The amino group in lysine's side chain can accept a proton (H⁺) under physiological pH, making it positively charged.
4. Compare lysine's properties to the amino acid categories: Positively charged amino acids have side chains that are basic and can carry a positive charge. Lysine fits this description.
5. Conclude the classification: Based on its positively charged side chain, lysine is classified as a positively charged amino acid.

Key Concepts

Amino Acid Classification

Amino acids are organic compounds that serve as the building blocks of proteins. They are classified based on the properties of their side chains (R groups) into three categories: positively charged (basic), negatively charged (acidic), and electrically neutral (nonpolar or polar). This classification is crucial for understanding protein structure and function.

Positively Charged Amino Acids

Positively charged amino acids, also known as basic amino acids, have side chains that contain amine groups, which can accept protons (H+ ions) at physiological pH. This results in a net positive charge. Common examples include lysine, arginine, and histidine, which play important roles in protein interactions and stability.

Lysine

Lysine is an essential amino acid classified as positively charged due to its side chain containing an amino group that can be protonated. It is crucial for protein synthesis, hormone production, and calcium absorption. Lysine's positive charge contributes to its interactions with negatively charged molecules, influencing protein structure and function.