Which of the following statements regarding the similarity in glycogen in animal cell and starch in plant cell is/are NOT correct? 1. Both are mixtures of amylose and amylopectin 2. Starch and glycogen, both represent the storage form of carbohydrate in liver cells Select the answer using the code given below:
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Correct answer
Explanation
The correct answer is C, Both 1 and 2. Neither statement is correct: only starch is a mixture of amylose and amylopectin, and only glycogen is stored in liver cells.
Starch and glycogen are both polysaccharides made of glucose units, and both serve as stored food. Starch is the reserve of plants, kept in granules in seeds, tubers and leaves. It is a mixture of two kinds of molecules: amylose, a mostly straight chain, and amylopectin, a branched chain. Glycogen, often called animal starch, is the reserve of animals and fungi. It is a single, very highly branched molecule, more branched than amylopectin, and is stored mainly in the liver and the muscles. So statement 1 fails for glycogen and statement 2 fails for starch.
Option A is wrong because statement 2 is also incorrect. Option B is wrong because statement 1 is also incorrect. Option D is wrong because both statements are incorrect, not correct.
Exam tip: starch = amylose + amylopectin, in plants; glycogen = highly branched, in liver and muscles.
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