Question

Mast cells contain vesicles that store a large amount of histamine. After staining with eosin, these vesicles are stained in red color. Which of the following interactions are involved between histamine and eosin?

• A. Electrostatic interaction
• B. Hydrogen bonding
• C. Hydrophobic interaction
• D. Covalent bonding

Answer 1

The Correct Option is A

Step 1: Understanding the Nature of Histamine and Eosin - Histamine is a small, positively charged molecule stored in mast cell vesicles. - Eosin is an acidic dye that binds to basic (positively charged) molecules. - Since histamine is basic and eosin is acidic, the interaction between them is primarily electrostatic. 

Step 2: Evaluating the Interaction Types - Electrostatic Interaction (Correct): The positive charge on histamine attracts the negative charge of eosin, forming an ionic interaction. - Hydrogen Bonding (Incorrect): While hydrogen bonding can occur, it is not the primary reason eosin binds to histamine. - Hydrophobic Interaction (Incorrect): Histamine is hydrophilic, making hydrophobic interactions unlikely. - Covalent Bonding (Incorrect): Covalent bonds are strong and permanent, but eosin binding is reversible, ruling out this option. 

Step 3: Conclusion Since eosin binds to histamine due to opposite charges, the correct interaction type is electrostatic interaction.