Very short question

1. Name the simplest form of carbohydrates?

Ans: Glucose.

2. Name the bond which joins the two saccharide molecules.

Ans: Glycosidic bond

3. What is nucleic acid?

Ans: Nucleic acids are long chain macromolecules of nucleiotide with high molecular weight. They are composed of pentose sugar, phosphoric acids and nitrogen base.

4. Name the components of nucleotide?

Ans: Nitrogen base, Phosphate and sugar molecule.

5. Name the nitrogenous bases present in nucleic acid?

Ans: Purine and Pyramidine.

6.How many types of nitrogenous bases present in nucleic acids?

Ans: There are two types of nitrogenous bases present in nucleic acids.

Short question

1. Define bio molecules? Mention its type?

Ans An organic compound normally present as an essential component of living organism. Following are the types

1) Water: Being the universal solvent and major constituents (60%) of any living body without which life is impossible. It acts as a media for the physiological and biochemical reactions in the body itself. Maintain the body in the required turgid condition.

2) Carbohydrates: It is very important for source of energy for any physical body function.

3) Proteins: These are very important from body maintenance point of view,helps in tissue, cell formation.

4) Lipids: These are very important from energy source as well as human nutrition point of view.

5) Nucleic Acids: Nucleic acids are very important as DNA carries the hereditary information and RNA helps in protein formation for the body.
 
6) Enzymes: Enzymes are simple or combined proteins acting as specific catalysts and activates the various biochemical and metabolic processes within the body.

2. Discus the types of carbohydrates?

Ans: Carbon hydrogen and oxygen is the main constituent of the carbohydrates. Where hydrogen and oxygen are present in the ratio of 2:1 as in water. Carbohydrate divides in 3 types.

i) Monosaccharides: it is the simplest form of the carbohydrate. The general formula is CnH2nOn. For e.g. glucose, fructose etc. they are soluble in water and usually sweet in taste.

ii) Disaccharides: they are formed by two molecules of the monosaccharides. For e.g. maltose, sucrose, lactose. They also soluble in water and sweet in taste.

iii) Polysaccharides

They are formed by the large number of monosaccharides and having several million molecular weights. They are insoluble in water and not sweet in taste. The common polysaccharides are starch, glycogen and cellulose. Starch is the reserved food material in plant.

3.Mention the biological significance of carbohydrate?

Ans: The biological significance of carbohydrates to living things can hardly be overemphasized. The energy stores of most animals and plants are both carbohydrate and lipid in nature; carbohydrates are generally available as an immediate energy source, whereas lipids act as a long-term energy resource and tend to be utilized at a slower rate. Glucose, the prevalent uncombined, or free, sugar circulating in the blood of higher animals, is essential to cell function. The proper regulation of glucose metabolism is of paramount importance to survival.

The ability of ruminants, such as cattle, sheep, and goats, to convert the polysaccharides present in grass and similar feeds into protein provides a major source of protein for humans. A number of medically important antibiotics, such as streptomycin, are carbohydrate derivatives. The cellulose in plants is used to manufacture paper, wood for construction, and fabrics.

4. Discuss protein as an important molecule?

Ans: Protein is important molecule due to following reason:

 (1) Membrane Proteins:

Proteins and lipids form the major structural components of cell membrane. The membrane associated proteins consists of intrinsic proteins and extrinsic proteins. Many enzymes and enzyme systems are associated with membrane proteins i.e. components of electron transport system.

(2) Enzymes:

Enzymes are proteins produced within an organism which are capable of catalyzing specific catalytic reactions. They are biocatalysts which influence the rate f a chemical reaction, usually without undergoing any change themselves.

(3) Hormones:

Several hormones are peptides and proteins. They play an important role in the regulation of metabolic reactions.

(4) Blood proteins:

The blood proteins include plasma proteins and hemoglobin.

5. Describes the structure and function of amino acid?

Ans: Ans: Amino acids are building blocks of proteins. They are micromolecule having carbon, hydrogen and oxygen group. Each amino acid is a nitrogenous compound having an acidic carboxyl (-COOH) and a basic amino (-NH₂)group. About 20 amino acids are occurring naturally. According to the body which synthesis amino acid it can be divided into two types, i.e. essential and non-essential.

6.Differentiate the essential and non-essential amino acids?

Ans: Difference between the essential and non-essential amino acids as follow:

7. How is the peptide bond formed?

Ans: Peptide bond is formed in amino acid during the protein formation. Amino acids are building blocks of proteins. They are micromolecule having carbon, hydrogen and oxygen group. Each amino acid is a nitrogenous compound having an acidic carboxyl (-COOH) and a basic amino (-NH₂)group. About 20 amino acids are occurring naturally. According to the body which synthesis amino acid it can be divided into two types, i.e. essential and non-essential.

8.Describe the structure of DNA as proposed by Watson?

Ans: Ans: J.D. Watson and F. crick (1953) combined the physical and chemical bata generated by early work and purposed a double helix model for DNA molecule. This model is widely accepted. According to this model, the DNA molecule consists of two strand which are connected together by hydrogen bonds and helically twisted. Each step on the one strand consist of a nucleotide of purine base which alternate with that of pyrimidine base. Thus, a strand of a DNA molecule is a polymer of four nucleotide i.e. A, G, T, C. the two strand join together to form double helix. Bases of two nucleotide form hydrogen bond i.e. A combines with T by two H-bond (A=T) and G combines with C by three hydrogen bond. However, the sequence of bonding is such that for every A.T.G.C. On one strand there would be T.A.C.G. on the other strand. Therefore, the two strand are complementary to each other. The two strands of double helix run in antiparallel direction, i.e. they have opposite polarity.

Fig: Structure of DNA (Watson and Crick Model)

The hydrogen bonds between the two strands are such that maintain a distance of 20 A⁰. The double helix coils in right hand direction. The turning of double helix results in the formation of a deep and wide groove called major groove. The major groove is the site if bonding of specific protein. The distance between two strands forms a minor groove. The DNA model also suggested a copying mechanism of the genetic material. DNA replication is the fundamental and unique event underlying growth and reproduction in all living organism ranging from the smallest viruses to the most complex of all creatures including man. DNA replicates by semi conservative mechanism.

9. Explain the different types of lipid?

Ans: The lipids are the important constituents of the diet because of their high energy value and also because of the fat soluble vitamins and the essential fatty acids found with the fat of the natural foodstuffs.

The lipids are a heterogeneous group of compound related to fatty acids and include fats, oils, waxes and other related substance. These are oily and greasy organic substance, relatively insoluble in water and soluble in organic solvents like ether, chloroform and benzene. Thus, they are hydrophobic in nature. They are classified into three types.

1. Simple lipids: these are ester of fatty acid with various alcohols.

a. fats and oils: these are ester of fatty acid with a trihydroxy alcohol, glycerol. A fat is solid at ordinary room temperature whereas oil is liquid.

b. waxes: these are esters of fatty acid with high molecular weight monohydroxy alcohols. 

2. Compound lipids: these are ester of fatty acids with alcohol and possess additional groups also.

10.Differentiate

i. Saturated and unsaturated fatty acids.

Ans: Different between saturated and unsaturated fatty acid as follows:

Saturated fats are solid at room temperature. They are mainly animal fats such as beef, pork and chicken and in animal products such as milk, butter, cheese and eggs. Unsaturated fats are liquid at room temperature. These are mainly plant fats such as corn, safflower, olive, walnut, canola and others.Saturated fatty acids have carbons joined via single bonds only, Unsaturated have both double bonds and single bonds between the carbon atoms
Saturated fatty acids have already formed the maximum number of double hydrogen bonds, while unsaturated ones have not

ii.Oil and fats.

Ans: different of fats and oil as follows:

11. Describe types and function of RNA?

Ans: Structure of RNA: The RNA is usually single stranded except viruses such as  TMV, yellow mosaic virus, reovirus etc. RNA is found both in the nucleus and in the cytoplasm. The single strand of the RNA is folded either at certain regions or entirely to form hairpin shaped structure. The RNA dose not possess equal purine-pyrimidine ratio, as is found in the DNA.

Fig: Structure of RNA.

Like DNA, the RNA is also the polymer of four nucleotides each one contains D-ribose, phosphoric acid and a nitrogenous base. The bases are two purines (A,G) and two pyrimidines (C,U). Thyamine is not found in RNA. Pairing between bases occurs as A-U and G-C.

 If the RNA is involved in genetic mechanism, it is called genetic RNA as found in plant, animal, and bacterial viruses. The DNA acts as genetic material and RNA follows the order of DNA, In such cells the RNA dose not have genetic role. Therefore, it is called non-genetic RNA. The non- genetic RNA is of three types:

1. m-RNA(messenger RNA): it constitutes about 5% - 10% of the total RNA present in the cell, m-RNA  carries the genetic information from DNA for Protein synthesis.

2. r- RNA(Ribosomal RNA): It makes about 80% of the total RNA in the cell. It is the major component of ribosomal.

3. t RNA (Transfer RNA): it is also known as soluble RNA. It forms about 10% - 15% of the total RNA. It used to transfer amino acid molecule to the site of protein synthesis.

A nucleotide is made up of three molecules. These are

a) Pentose sugar: the pentose sugar is ribose.

b) Nitrogenous bases:  i) Purine = Adenine And Guanine ii) Pyrimidine=Cytosine And Uracil

c) Phosphoric Acid

12.Differentiate DNA and RNA.

Ans: Different between DNA(Deoxyribonucleic acid) and RNA(Ribonucleic acid)

13. “Water is Essential for life” Explain.

Ans:  Water is the mother liquor of all forms of life. It is the vital essence, miracle of nature, and the great sustainer of life. The essentiality of water for living system is quite evident a without water, there is no life. In human adult total body water accounts for about 70% of the lean body mass. In plant it makes about 70%-90% of the living matter of active cells. In many hydrophytes and fruits, water appears in even high percentage. A greater portion of water is found in free form that means the water which is available for the metabolic process.

Function of water

i)Water is a universal solvent.

ii) It is used as a raw material in photosynthesis.

iii) It also help in transpiration due to turgor pressure.

Iv)it also maintain the turgidity of cells and their organelles.

14.What are essential minerals? Write its function?

Ans: A mineral is defined as inorganic element containing no carbon that remains as ash when food is burned. Although as many as 40 minerals are in existence, the table below describes the 17 minerals that are essential to human nutrition and lists their functions and sources in food.

The general function of minerals and trace elements can be summarised as follows:

1.Minerals are essential constitutents of skeletal structures such as bones and teeth.

2.Minerals play a key role in the maintenance of osmotic pressure, and thus regulate the exchange of water and solutes within the animal body.

3.Minerals serve as structural constituents of soft tissues.

4.Minerals are essential for the transmission of nerve impulses and muscle contraction.

5.Minerals play a vital role in the acid-base equilibrium of the body, and thus regulate the pH of the blood and other body fluids.

6.Minerals serve as essential components of many enzymes, vitamins, hormones, and respiratory pigments, or as cofactors in metabolism, catalysts and enzyme activators.