Which are incorrect statements?

(a) Amylose is a component of cellulose

(b) Starch is a polymer of α- glucose

(c) Proteins are compounds of only one type of amino acids

(d) In the cyclic structure of fructose, there are four carbon atoms and one oxygen atom.

A, C and D

The correct answer is option 2. A, C and D.

Statement A: Amylose is a component of cellulose.

The statement is incorrect. Amylose and cellulose are two distinct polysaccharides with different structures and functions. Amylose is a type of starch, which is a storage polysaccharide found in plants. It consists of long chains of glucose molecules linked together through alpha-1,4 glycosidic bonds. Amylose is often considered a straight-chain polymer, although it may form helical structures due to intramolecular hydrogen bonding.

Cellulose, on the other hand, is a structural polysaccharide that forms the primary component of plant cell walls. It is also composed of glucose units, but the linkage between them is beta-1,4 glycosidic bonds. Cellulose chains are extensively hydrogen-bonded to form a strong, fibrous structure, providing rigidity and strength to plant cells.

While both amylose and cellulose are composed of glucose units, their different glycosidic bond linkages and structural arrangements result in distinct properties and functions. Amylose is a storage form of glucose in plants, while cellulose provides structural support.

Statement B: Starch is a polymer of α- glucose

The statement is correct. Starch is indeed a polymer of α-glucose. Starch is a complex carbohydrate that serves as a storage form of energy in plants. It is composed of two main polysaccharides: amylose and amylopectin.

Amylose is a linear polymer of α-glucose molecules linked together by α-1,4 glycosidic bonds. It forms a helical structure due to intramolecular hydrogen bonding. Amylose accounts for a smaller portion of starch and has a lower degree of branching.

Amylopectin, on the other hand, is a branched polymer of α-glucose units linked by α-1,4 glycosidic bonds with occasional α-1,6 glycosidic bonds at branching points. Amylopectin is highly branched, resulting in a more compact and soluble structure compared to amylose. Together, amylose and amylopectin make up starch, which serves as an energy reserve in plants. When consumed, starch is broken down by enzymes in the body to release glucose for energy metabolism.

Statement C: Proteins are compounds of only one type of amino acids

The statement is incorrect. Proteins are not compounds of only one type of amino acid. Proteins are made up of 20 different amino acids that are linked together by peptide bonds. The sequence of amino acids in a protein determines its structure and function.

The different amino acids have different chemical properties, which gives proteins their diversity of structure and function. For example, some amino acids are polar, while others are nonpolar. Some amino acids are acidic, while others are basic. These different properties affect how the amino acids interact with each other and with other molecules.

The sequence of amino acids in a protein is determined by the DNA sequence of the gene that codes for the protein. The DNA sequence is transcribed into RNA, and the RNA is translated into protein. The sequence of amino acids in a protein determines its structure and function.

Therefore, the statement that proteins are compounds of only one type of amino acid is false.

In cyclic structure of fructose, there are four carbon

Statement D: In cyclic structure of fructose, there are four carbon atoms and one oxygen atom.

The statement is incorrect. In the cyclic structure of fructose, there are five carbon atoms and one oxygen atom. Fructose is a monosaccharide, or simple sugar, and it is commonly found in fruits and sweeteners. It exists in both linear and cyclic forms, but the cyclic structure is more stable in aqueous solutions.

The cyclic structure of fructose is formed through an intramolecular reaction between the carbonyl group (C=O) at carbon 2 and the hydroxyl group (OH) at carbon 5. This reaction results in the formation of a hemiacetal, which leads to the formation of a five-membered ring called a furanose ring.

In the cyclic structure of fructose, there are five carbon atoms numbered from 1 to 5. Carbon 1 (C1) is part of the furanose ring and is bonded to an oxygen atom. The remaining four carbon atoms (C2, C3, C4, and C5) are within

Please note that this representation only shows the basic carbon and oxygen atoms, and it does not include the hydrogen and hydroxyl groups attached to these atoms.