Answer: Iodine solution.
- A Iodine solution
- B Fehling's solution
- C Biuret reagent
- D NaOH
Correct answer: A. Iodine solution
Explanation: Iodine gets trapped in the helical structure of amylose in starch, giving the characteristic blue-black colour.
Two amino acids join via a condensation reaction: the carboxyl -OH of one and an amine -H of the other are eliminated as water, leaving a peptide bond (-CO-NH-) linking them into a dipeptide; repeating this builds a full protein chain.
Concept context
The chemistry of life: carbohydrates, proteins, lipids, nucleic acids, enzymes, and vitamins. Understand their structures, classification, and biological functions. Highly relevant for NEET and Class 12 board exams.