Which of the following is an example of a functional group in organic chemistry?

• A. Peptide bond
• B. Hydroxyl group ($-OH$)
• C. Gram-positive bacterium
• D. Nucleotide

Answer: (B)

Verified step by step guidance

1. Understand the concept of functional groups: In organic chemistry, a functional group is a specific group of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
2. Identify common functional groups: Some common functional groups include hydroxyl (-OH), carboxyl (-COOH), amino (-NH2), and methyl (-CH3).
3. Analyze the options given: Look at each option and determine if it represents a functional group. A peptide bond is a type of bond, not a functional group. A gram-positive bacterium is a type of organism, and a nucleotide is a building block of nucleic acids.
4. Recognize the hydroxyl group: The hydroxyl group (-OH) is a well-known functional group in organic chemistry, often found in alcohols.
5. Conclude that the hydroxyl group is the correct answer: Based on the analysis, the hydroxyl group (-OH) is the example of a functional group among the given options.