Question

Differentiate between the following :
(i) Acidic amino acids and basic amino acids
(ii) Nucleotide and Nucleoside

Hint:

Memory aid: Nucleo{s}ide = {S}ugar + Base. Nucleo{t}ide = {T}ri-component (Sugar + Base + Phosphate).

Answer 1

Step 1: Understanding the Concept:
Amino acids and nucleic acids are the building blocks of proteins and DNA/RNA respectively. Their properties depend on their functional groups.
Step 2: Detailed Explanation:
(i) Acidic vs Basic Amino Acids:
Acidic Amino Acids: These contain more carboxyl groups (\( -COOH \)) than amino groups (\( -NH_2 \)) in their structure. Example: Glutamic acid, Aspartic acid.
Basic Amino Acids: These contain more amino groups (\( -NH_2 \)) than carboxyl groups (\( -COOH \)) in their structure. Example: Lysine, Arginine.
(ii) Nucleotide vs Nucleoside:
Nucleoside: It is formed by the linkage of a nitrogenous base to the 1' position of a pentose sugar (Sugar + Base).
Nucleotide: It is formed when a phosphoric acid group is attached to the nucleoside at the 5' position of the sugar (Sugar + Base + Phosphate). Thus, a nucleotide is a phosphoric acid ester of a nucleoside.
Step 3: Final Answer:
(i) Difference lies in the excess of acidic vs basic functional groups.
(ii) Nucleotides contain phosphate; nucleosides do not.