Starch is a polymeric carbohydrate consisting of about 5-10 glucose units joined by glycosidic bonds. Group of answer choices True False
The correct answer and explanation is:
The correct answer is False.
Starch is a polymeric carbohydrate, but it consists of two types of polysaccharides: amylose and amylopectin, which are composed of hundreds to thousands of glucose units, not just 5-10. These glucose units are linked together by glycosidic bonds, specifically α-1,4-glycosidic bonds in amylose and α-1,4 and α-1,6-glycosidic bonds in amylopectin.
Amylose is a linear chain of glucose molecules connected by α-1,4-glycosidic bonds, and amylopectin is a branched polymer that has both α-1,4 and α-1,6-glycosidic bonds. The structure of amylopectin allows it to form a more compact and branched structure compared to amylose. These two components make starch an efficient energy storage molecule in plants.
Starch is primarily found in plant tissues like potatoes, corn, and rice, where it serves as a storage form of glucose, which plants can later break down into simple sugars for energy. The structure of starch allows it to be readily broken down by enzymes like amylase, which hydrolyze the glycosidic bonds to release glucose.
The statement in the question refers to a much smaller scale of polymer than starch. The correct description of starch would involve the presence of hundreds to thousands of glucose units, rather than just a small chain of 5-10. The long chains of glucose units in starch enable it to function effectively as an energy reserve, providing plants with a long-term source of energy during periods when photosynthesis is not occurring or when energy storage is needed.