Class 12th

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

Hydrogen bonds hold the α− helical structure of proteins together. A polypeptide chain creates all potential hydrogen bonds by twisting into a

right-handed helix with the −NH group of each amino acid residue hydrogen linked to a>C=O neighboring turn of helix.

Correct option is C

This is a multiple choice answer as classified in NCERT Exemplar

(a) Salvarsan is arsenic containing drug which was first used for treatment of syphilis. Syphilis is an acute and chronic infections disease caused by the bacterium Treponema pallidum. It is a sexually transmitted infection. The primary route of transmission is through sexual contact but it may also be transmitted from mother to foetus during pregnancy or at birth.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The configuration of different anomers  at C-I is distinct. It is known as the form if the hydroxyl group (-OH) is present on the right side of anomeric carbon, and it is known as the? form if the hydroxyl group is present on the left side. As a result, option (c) represents anomers among all the supplied pairs.

Correct option is c.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

Sucrose is a disaccharide (sometimes known as cane sugar). One molecule of glucose and one molecule of fructose are produced when sucrose is digested. The reaction is depicted in the diagram below.

Correct option is c.

This is a multiple choice answer as classified in NCERT Exemplar

(a) Tranquilizers are neurologically active drugs. Some tranquilizers are antidepressants and the functions by inhibiting the enzymes which catalyse the degradation of noradrenaline.

If the enzyme is inhibited, the neurotransmitter noradrenaline is slowly metabolized and can thus activate the receptor for longer periods there by counteracting the effect of depression. Tranquilizers form an essential component of sleeping pills.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

Ans: The Correct option is b. In humans and animals, glycogen is mostly synthesized and stored in the liver and skeletal muscle cells. Glycogen accounts for around 5-6% of the liver's fresh weight, and an adult liver weighing  1.5kg can store approximately 100-120 gms of glycogen.

This is a multiple choice answer as classified in NCERT Exemplar

(c) The most useful classification of drugs for medicinal chemists. It is on the basis of molecular targets. Target molecules are usually biomolecules like carbohydrates, lipids, proteins and nucleic acids. These drugs possess some common structural features, may have the same mechanism of action on a specific drug target.

This is a Multiple Answer Type Questions as classified in NCERT Exemplar

The Correct option is b Glycogen resembles amylopectin in structure. It's a ? −D− glucose unit branched chain polymer with C₁−C₄ glycosidic linkage and C1−C6 glycosidic linkage branching. The structure of amylopectin is depicted in the diagram below.

This is a multiple choice answer as classified in NCERT Exemplar

(a) Aspirin inhibits the synthesis of compounds known as prostaglandins which stimulate inflammation in the tissues and cause pain. So, it is effective in relieving pain.

Aspirin has many other effects such as reducing fever (antipyretic) and preventing blood platelet coagulation. Because of this anti-blood clotting action, it is widely used to prevent heart.attacks. It does not make a person addictive as it is non-narcotic drug.