Answer: Plant cell walls.
- A Plant cell walls
- B Animal cell membranes
- C Animal bones
- D Bacterial cell walls
Correct answer: A. Plant cell walls
Explanation: Cellulose provides structural rigidity to plant cell walls.
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.