Ques. 1AIPMT 2001
Which is the correct statement?
- Starch is a polymer of -glucose.
- Amylose is a component of cellulose.
- Proteins are composed of only one type of amino acid.
- In cyclic structure of fructose, there are four carbons and one oxygen atom.
Answer
(1) Starch is a polymer of -glucose.
Solution
(1) Correct: as per NCERT, starch is a polymer of -glucose (amylose and amylopectin).
(2) Incorrect: amylose is a component of starch; cellulose is a straight-chain polymer of -glucose.
(3) Incorrect: proteins are polymers of many different -amino acids joined by peptide bonds.
(4) Incorrect: cyclic fructose (furanose form) has a five-membered ring of four carbons and one oxygen, but the cyclic structure as a whole contains six carbon atoms (C-1 and C-6 are outside the ring as -CH2OH groups).
Answer: (1)