Problem 30 - A Complete Resource Book in Chemistry for JEE Main

Question

A broad spectrum antibiotic is (a) penicillin (b) paracetamol (c) chloramphenicol (d) aspirin

Step-by-Step Solution

Answer

Chloramphenicol is a broad-spectrum antibiotic.

Step 1: Understanding the question

The exercise asks us to identify which among the given options is a broad-spectrum antibiotic. Broad-spectrum antibiotics are those that are effective against a wide variety of bacteria, both Gram-positive and Gram-negative.

Step 2: Analyzing the options

Let's go through each option to determine if it is a broad-spectrum antibiotic: - (a) Penicillin: Mainly effective against Gram-positive bacteria. - (b) Paracetamol: A pain reliever and fever reducer, not an antibiotic. - (c) Chloramphenicol: Known to be a broad-spectrum antibiotic effective against both Gram-positive and Gram-negative bacteria. - (d) Aspirin: Used to relieve pain, reduce fever, and has anti-inflammatory properties, but is not an antibiotic.

Step 3: Selecting the correct option

From the analysis, chloramphenicol is identified as a broad-spectrum antibiotic as it is effective against a wide range of bacteria.

Key Concepts

Chloramphenicol

Chloramphenicol is a powerful antibiotic that is effective against a wide range of bacteria, earning it the title of a broad-spectrum antibiotic. It works by inhibiting bacterial protein synthesis, which is crucial for bacterial growth and reproduction.
Due to its wide-ranging effectiveness, chloramphenicol can be used to treat various infections, including those caused by both Gram-positive and Gram-negative bacteria.
This makes it particularly useful in treating bacterial infections in situations where the exact type of bacteria is unknown or in mixed infections. However, one must be cautious, as chloramphenicol can have significant side effects, such as bone marrow suppression. This highlights the importance of responsible antibiotic use.

Gram-positive bacteria

Gram-positive bacteria are a class of bacteria characterized by their thick peptidoglycan cell walls. This structural feature retains the crystal violet dye used in Gram staining, a common laboratory technique, resulting in a purple color.
Examples of Gram-positive bacteria include

• Staphylococcus
• Streptococcus
• Bacillus
• Clostridium species

Gram-positive bacteria often respond well to antibiotics like penicillin, which target cell wall synthesis. However, broad-spectrum antibiotics like chloramphenicol are also effective against Gram-positive bacteria, offering flexibility in treatment options.

Gram-negative bacteria

Gram-negative bacteria possess a thinner peptidoglycan layer compared to Gram-positive bacteria, but have an additional outer membrane. This unique structure does not retain the crystal violet dye during Gram staining, and instead, these bacteria appear pink.
Examples of Gram-negative bacteria include

• Escherichia coli
• Salmonella
• Pseudomonas
• Neisseria species

This outer membrane makes Gram-negative bacteria more resistant to antibiotics that target the cell wall. Therefore, they often require treatment with broad-spectrum antibiotics like chloramphenicol, which can penetrate this barrier and disrupt protein synthesis.

Antibiotics vs Pain Relievers

Antibiotics and pain relievers, such as paracetamol and aspirin, serve very different purposes and should not be confused. Antibiotics like chloramphenicol are used to combat bacterial infections. They work by targeting features unique to bacteria, such as cell wall construction or protein synthesis.
On the other hand, pain relievers and fever reducers such as paracetamol and aspirin are drugs designed to alleviate symptoms like pain and fever caused by a variety of conditions, including infections, without affecting the underlying bacteria.
It's crucial to use the right type of medication depending on the condition being treated: antibiotics for bacterial infections, and pain relievers for symptomatic relief of conditions such as headaches, muscle pain, or minor injuries. Misuse of antibiotics can lead to resistance, while inappropriate use of pain relievers can lead to side effects like liver damage (in the case of paracetamol) or gastrointestinal issues (with aspirin).