Test: Biomolecules- Carbohydrates, Proteins & Enzyme (March 2) - NEET MCQ

Sucrose or cane sugar is the commonest of the disaccharides. It has the molecular formula C₁₂H₂₂O₁₁. It does not form a phenylhydrazone or exhibit carbonyl properties. On hydrolysis with dilute acids, it yields one molecule of D-(+)-glucose and one molecule of D-(—)-fructose. It is not a reducing sugar. 

Lactose: The sugar found naturally in milk, it is a disaccharide composed of one galactose unit and one glucose unit; sometimes called milk sugar.

Because it is the chemical property of aliphatic aldehyde to give red precipitate with fehling solution.

RCHO + 2 CuO -----------> Cu₂O. + RCOOH

Fehling reagents is aq. alkaline CuSO₄ solution along with Rochelle salt Na-K tartrate.
And glucose molecule consists of aldehydic group at first position and hence it is also a aldehyde and thus give this characteristic test.

The given carbohydrate is α - D - (-) - Fructofuranose. This is because the -OH group is present on the right hand side.

Fehling's solution to make difference between carbohydrate and ketone functional grp and also used for differentiate reducing and non reducing sugar and as u know glucose is a reducing sugar so it will give red colour with fehling's solution (all monosachharides are reducing sugar).

Explanation: Proteins are heteropolymers of amino acids. This means that out of the 20 amino acids, various combinations of the amino acids may result in the formation of a protein. This protein may be functional or non-functional

The correct answer is option D
α helix is one of the most common ways in which a polypeptide chain forms all possible hydrogen bonds (intermolecular and intramolecular hydrogen bond) by twisting into a right-handed screw(helix) with the N−H group of each amino acid residue hydrogen bonded to C=O of an adjacent turn of the helix.
 

The correct answer is A
Haemoglobin is a Quaternary protein because it has 4 polypeptide structures - 2alpha and 2 beta.

Glycine is the simplest amino acid and is the only amino acid that is not optically active (it has no stereoisomers).

Nonessential amino acids can be synthesized in the body, whereas essential amino acids must be obtained in the diet. Cells in the body can provide the carbon skeleton of the nonessential amino acids.