Chemistry 3 Marks Question

1. Maltose.
2. In acidic amino acid more carboxyl groups as compared to amino groups are present & In basic amino acid more number of amino than carboxyl groups are present.
3. Phosphodiester linkage.

1. A linkage between two monosaccharide units through oxygen atom is called glycosidic linkage.
2. Hydrolysis of sucrose brings about a change in the sign of rotation, from dextro (+) to laevo (–) and the product is named as invert sugar.
3. Carbohydrates that yield two to ten monosaccharide units on hydrolysis, are called oligosaccharides.

1. Mrs. Anuradha has shown generosity/caring/helping/kindness attitude towards poor.
2. Vit. B12.
3. Vitamin B/C.

Acidic amino acids contain more number of carboxyl groups than amino groups. Basic amino acids contain more number of amino groups than carboxyl groups. Neutral amino acids contain equal number of amino acids and carboxyl groups.

1.  

2. Peptide linkage/ -CO-NH- linkage
3.  

1. Vitamin C.
2. Peptide linkage.
3. n-hexane or its structure.

1. Maltose.
2. Fibrous proteins: parallel polypeptide chain, insoluble in water, Globular proteins: spherical shape, soluble in water.
3. Vitamin D.

1. Sonali: Concerned for the society, socially active and helpful to others. Principal: Caring, commanding and serious about the welfare of students.
2. Vitamins B and C.

1. Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharides. Starch, cellulose, glycogen and gums are most common examples.
2. When native protein is subjected to physical change such as change in temperature or a chemical change 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.

Loss of biological activity by the protein is called denaturation.

3. Amino acids which cannot be synthesised inside our body and must be obtained through the diet are called essential amino acids. Examples: Valine, leucine, isoleucine.

1. Carbohydrates that yield two to ten monosaccharide units, on hydrolysis, are called oligosaccharides.

Example: Sucrose or any other.

2. When a protein in its native form, is subjected to physical change like change in temperature or chemical change like change in pH, the hydrogen bonds are disturbed. Due to this, globules unfold and helix get uncoiled and protein loses its biological activity.

Example: Boiling of egg.

3. Organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism.

Example: Vitamin A.

1. Protein synthesis occurs at the ribosome in the cytoplasm.
2. More than one codon (a combination of three nucleotide, i.e., triplet) can code for the same amino acids, e.g., proline is encoded by CCU, CCA, CCG and CCC.
3. First two bases of a codon are more important for coding, the third being less specific.

Complete hydrolysis of DNA yields a pentose sugar, phosphoric acid and nitrogen containing heterocyclic compounds called bases.

A unit formed by the attachment of a base to I ‘-position of sugar is called nucleoside. When nucleoside links to phosphoric acid at 5′-position of sugar moiety, a nucleotide is formed. Nucleotides are joined together by phosphodiester linkage between 5’-and 3’carbon atoms of the pentose sugar.

In DNA, two chains of nucleic acid coil about each other and held together by H-bonds between bases of two chains.

1. Anomers.
2. Since these anomers are not mirror images of each other so they cannot be called as enantiomers.
3.  

1. Monosaccharides: The simple carbohydrates that cannot be broken further into smaller units on hydrolysis, e.g., glucose and fructose, ribose, etc.
2. Oligosaccharides: These are the carbohydrates which on hydrolysis give two to ten units of monosaccharides, e.g., sucrose, maltose, raffinose, stachyose, etc.
3. Polysaccharides: These are the carbohydrates which produce a large number of monosaccharide units on hydrolysis, e.g., starch, cellulose, etc.

1. This indicates that the aldehyde group in glucose is not free.
2.  

3. ‘D’ gives the configuration, i.e., the -OH group at C-5 is on the right hand side. (+) sign indicates that the isomer is dextrorotatory.

The Fischer projection of L-Glucose is the mirror image of D-Glucose.

Starch is the main storage polysaccharide of plants. It is the most important dietary source for human beings. High content of starch is found in cereals. Cellulose occurs exclusively in plants and it is the most abundant organic substance in plant kingdom. Cell wall of bacteria and plants is made up of cellulose. We build furniture, etc. from cellulose in the form of wood and clothe ourselves with cellulose in the form of cotton fibre.

As we know that in DNA molecule, adenine (A) always pairs with thymine (T) and cytosine (C) always pairs with guanine (G). Thus,
Sequence of bases in one strand: A T G C T T C A
Sequence of bases in the complementary strand: T A C G A A G T.

The secondary structure of proteins arises due to the regular folding of the backbone of the polypeptide chain due to hydrogen bonding between  and -NH group of the peptide bond.

L-Glucose reduces Tollens’ reagent to metallic silver.