Amino acids are classified as positively charged, negatively charged, or electrically neutral.

Which category includes lysine?

Verified step by step guidance

1. Identify the chemical structure of lysine, focusing on its side chain.
2. Recognize that lysine has an amino group in its side chain.
3. Understand that the presence of an additional amino group can accept a proton, giving lysine a positive charge at physiological pH.
4. Classify lysine based on its ability to carry a positive charge due to its side chain.
5. Conclude that lysine is categorized 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.