Chemistry 1 Marks Question

The statement refers to the classification according to pharmacological effect of the drug because any drug which will be used to counteract the effect of excess acid in the stomach will be called antacid. Antacids are the medicinal agents which decreases the excess level of hydrochloric acid in stomach.

In the helical structure of DNA, the two strands are held together by hydrogen bonds between specific pairs of bases. Cytosine forms hydrogen bond with guanine, while adenine forms hydrogen bond with thymine. As a result, the two strands are complementary to each other.

The products obtained are 2-deoxy-D-ribose, Phosphoric acid and thymine.

In a biological system, a protein is found to have a unique 3-dimensional structure and a unique biological activity. In such a situation, the protein is called native protein. However, when the native protein is subjected to physical changes such as change in temperature or chemical changes such as change in pH, its H-bonds are disturbed. This disturbance unfolds the globules and uncoils the helix. As a result, the protein loses its biological activity. This loss of biological activity by the protein is called denaturation.
During denaturation, the secondary and the tertiary structures of the protein get destroyed, but the primary structure remains unaltered. One of the examples of denaturation of proteins is the coagulation of egg white when an egg is boiled.

Denaturation of proteins: Proteins are very sensitive to the action of heat, change of pH, presence of electrolytes and radiations (particularly of short wavelength). Whenever proteins are subjected to such changes in the surroundings, they undergo some structural changes leading to disruption of three dimensional structure. This causes permanent loss of activity to proteins. Disruption of the native conformation of protein, by changing its environment, resulting in loss of its biological activity, is known as denaturation of proteins.

The solubility of a solute in a given solvent follows the rule ‘Li ke dissolves like’.Glucose contains five and sucrose contains eight -OH groups. These -OH groups form H-bonds with water. As a result of this extensive intermoleeular H-bonding, glucose and sucrose are soluble in water.On the other hand, benzene and cyclohexane do not contain -OH bonds and hence do not form H-bonds with water. Moreover, they are non-polar molecules and hence do not dissolve in polar water molecules.

Denaturation of proteins is a process in which physical and biological properties of protein without changing the chemical composition of protein. In an egg denaturation of protein is the coagulation of albumin present in the white of an egg. When egg is boiled in water, the globular proteins present in it changes to a rubber like insoluble mass which absorbs all water present in the egg.

Primary structure: The primary structure of protein refers to the specific sequence in which various amino acids are present in it, i.e., the sequence of linkages between amino acids in a polypeptide chain. The sequence in which amino acids are arranged is different in each protein. A change in the sequence creates a different protein.

Vitamin C cannot be stored in our body because it is water soluble. As a result, it is readily excreted in the urine.

The ethereal or oxide linkage through which two monosaccharide units are joined together by the loss of a water molecule to form a molecule of disaccharide is called the glycosidic linkage. The glycosidic linkage in maltpse molecule is shown below:

1. Messenger RNA (m-RNA)
2. Ribosomal RNA (r-RNA)
3. Transfer RNA (t-RNA)

Galactose and Glucose.

2 molecules of Glucose.

Carbohydrates which reduce Tollen’s reagent or Fehling solution are called reducing sugars which have free aldehydic group.

1. Structural support.
2. Storage molecules.
3. Constituent of cell wall.

Glucose and fructose.

Amylopectin.

Amylose.

mRNA, rRNA, tRNA.

4-chlorobenzenesulphonic acid

Both Glucose and Fructose are hexose sugars with six carbon atoms but, Glucose is an aldohexose and Fructose is ketohexose which means the functional group present in glucose is aldehyde and the functional group in fructose is ketone.

Nucleosides are linked to phosphoric acid at 5′-position of sugar moiety to form a nucleotide. Further, nucleotides (two molecules) are joined together by phosphodiester linkage between 5′ and 3′ carbon atoms of pentose sugar to form dinucleotide. Phosphoric acid is involved in the formation of this linkage.

Valine is an essential amino acid whereas glycine is a non-essential amino acid.

The carboxyl group of glycine and amino group of alanine when combines together, they form glycylalanine through a peptide (-CO – NH) linkage.

1. To transmit genetic material to their offsprings.
2. Protein synthesis.

Lysine.

Vitamin K.

Carbohydrates have chiral or asymmetric carbon atom.

Vitamin C are soluble in water. Water soluble vitamins must be supplied regularly in diet because they are readily excreted in urine and cannot be stored in our body.

The letters ‘D’ or ‘L’ before the name of any compound indicate the relative configuration of a particular stereoisomer. This refers to their relation with a particular isomer of glyceraldehydes.
D’ before the name of glucose represents the configuration whereas ‘(+)’ represents dextrorotatory nature of the molecule. It may be remembered that ‘D’ and ‘L’ have no relation with the optical activity of the compound. For assigning the configuration of monosaccharides, it is the lowest asymmetric carbon atom which is compared. The given compound has L-configuration.

Enzymes arehighly specific. They react with substrate molecule and form intermediate complex. They reduce the magnitude of activation energy.

Cyanocobalamin.

Amino acids.

Glycogen.

Keratin being a fibrous protein insoluble in water.

Albinism and phenylketonuria.

It helps in protective blood clotting.

Adenine and guanine.

Lactose is present in milk. Two monosaccharide units (i.e., glucose and galactose) are present in it. Such oligosaccharides are called disaccharides.

Phosphoric acid unit is linked preferably at 5′-position of sugar moiety of a nucleoside to give a nucleotide.

Globular protein and its shape is spherical.

Curdling of milk.

Starch and glycogen.

Vitamin C.

The main structural feature of reducing sugars is the presence of an aldehyde group (-CHO) such as in glucose, mannose, galactose, etc. or a-ketol group (-CO- CH2OH) as present in fructose.

Glucose pentaacetate (structure A) doesn’t have a free —OH group at C1 and so can’t be converted to the open chain form to give —CHO group and hence doesn’t form the oxime.

Messenger RNA (mRNA) and transfer RNA (tRNA).

Phenylalanine is an essential amino acid.

Oxidoreductase is class of enzymes which catalyse the oxidation of one substrate with simultaneous reduction of another substrate.

Glycosidic linkage.

Carbohydrates which on hydrolysis give 2-10 molecules of monosaccharides are called oligosaccharides. For example, sucrose, raffinose, stachyose, etc.

Vitamin B, Vitamin C.

Ascorbic acid.

Uracil.

Liver and adipose tissue.

D-(+)- Glucose and D-(-)- fructose.

Streptokinase.

Pepsin, trypsin.

When milk is curdeled, its sugar get oxidize to form lactic acid.

Adenosine triphosphate (ATP).

It is due to the fact that human beings do not have enzyme to digest cellulose.

Amylase.

Globular proteins (Enzymes).

Cellulose.