Question

Why are Glu and Asp often referred to as acidic amino acids?

Short answer

Answer: Glutamic acid (Glu) and Aspartic acid (Asp) are called acidic amino acids due to the presence of a carboxyl group (-COOH) in their side chains, which can ionize and lose a hydrogen ion (H+). This property allows them to act as proton donors or acids in a chemical reaction and have a negative charge at physiological pH. This acidic nature sets them apart from other amino acids.

Step-by-step solution

Introduction to Amino Acids

Amino acids are the building blocks of proteins. They contain a central carbon (C) atom, an amino group (-NH2), a carboxyl group (-COOH), and a side chain (R-group) which varies among different amino acids.

Understanding the Structure of Glutamic Acid (Glu) and Aspartic Acid (Asp)

Glutamic acid (Glu) and Aspartic acid (Asp) are two common amino acids found in proteins. Both these amino acids have side chains that end in a carboxyl group (-COOH). The structure of their side chains is as follows: - Glutamic acid (Glu): H2N-CH-COOH | -CH2-CH2-COOH - Aspartic acid (Asp): H2N-CH-COOH | -CH2-COOH

Explaining their Chemical Nature

The side chains of Glu and Asp contain a carboxyl group (-COOH) which can ionize and lose a hydrogen ion (H+). This property of Glu and Asp results in both amino acids being negatively charged at physiological pH (around 7.4). In simplified terms, the ionization can be represented as: - Glutamic acid (Glu): R-COOH ↔ R-COO- + H+ - Aspartic acid (Asp): R-COOH ↔ R-COO- + H+

Understanding why Glu and Asp are referred to as Acidic Amino Acids

Glu and Asp are called acidic amino acids due to the presence of the carboxyl group (-COOH) in their side chains. This carboxyl group can lose a hydrogen ion (H+) and has the capacity to donate a H+ ion to other molecules. As a result, they act as proton donors or acids in a chemical reaction and have a negative charge at physiological pH. This characteristic acidic nature of Glu and Asp sets them apart from other amino acids and earns them the title of acidic amino acids.