Tuesday, 2 September 2014


1) What are macromolecules? Give Example.

Macromolecules are large sized chemicals which get separated in acid insoluble fraction using trichloro acetic acid. They are polymers with a molecular mass of 1000 Daltons or above e.g. = Proteins, lipids.

2. Illustrate a glycoside, peptide and phosphodiester bond.

 Glycosidic bond:         It is a bond formed during dehydrate synthesis of polysaccharide with one monosaccharide providing hydroxyl (-OH) and other providing hydrogen ((-H) to form a molecules of water (HOH)

     The bond is generally –COC – or – CNC – C5H10O5 x HCOH + Ox CHO5H10C5

Peptide bond:         It is formed during dehydrate synthesis of a peptide with one amino acid and hydrogen to form water

H2NxCHxCOOH + HNxN – CH – COOH H2N – ChxCoxNH – CHxCOOH + H2o
 H2NxCHxCOOH + HNxN – CH – COOH H2N – ChxCoxNH – CHxCOOH + H2o
             R                                R                                        R                     R
Phosphodiester Bond: It is a double ester bond formed during dehydrate synthesis in the
Reaction between a phosphoric acid (HOHPO2OH) and two Pentose sugar. The bond is –OXHPO2x O- C4H7O3 x CH2OH +                         HOHPO2 x OH + HOCH2O3H7C4

C4H7O3.CH2O x HPO2OCH2O3H7O4 + 2H2O

3.   What do you meant by tertiary structure of proteins?

     It is a structure formed by folding of secondarily coiled polypeptide,a-helix and B  - pleated in such a way as to bring the functional side groups to the surface and inactive side group in the interior.

4. Find and write down structures of 10 interesting small molecular bio molecules. Find if here is any industry which manufactures the components by solution find out who are the buyers.

    The 10 interesting small molecular bio molecules are like alcohol, tartaric acid, lactic acid, citric acid, amino acid, trypsin, sucrose, gluconic acid & amylase.

5)   Proteins have primary structures, if you are given a method to know which amino acid is al liker of the two terminal (ends) of a protein, can you connect this information to purity or homogenising of a protein ?

     Simply knowing the two amino acids at the two ends of a protein cannot help in designating a protein as pure or homogeneous. It is because a protein is made of numerous amino acids. A difference of only one amino acid any where will make the protein different from the other. Only by sequencing the complete protein by Edman or songer’s technique can tell us about purity of a protein.

6.   Find out and make a list of protein used as therapeutic agents Find other applications of proteins

     THERAPEATIC USES: = Insulin, Oxytocin, ADH, Thrombin, fibrinogen Renin

Other applications –

a) Cosmetics: Proteins are used in beauty creams & shampoos e.g. = caesin.
b) Sweeteners: - Sweetest chemicals are proteins, threaten followed by monellin.
c) Dietary Proteins: It is added in diet supplements. For building & maintenance of health.

7. Explain the composition of triglyceride –

     They are natural or true fat in a biochemical formed by esterification of 3 molecules of fatty acids with one molecule of trihydric alcohol & glycerol. In pure fat, all the 3 fatty acids of triglyceride are similar (e.g. tripalmitin) while in mixed fat they are dissimilar (e.g. = dipalmitostearin)

8. Can you describe what happens when milk is converted into curd or yoghurt from your understanding proteins?

     Milk is inoculated with lactic acid bacteria. They convert milk sugar lactose into lactic acid. Lactic acid acids acts on globular milk protein casein, causes its denaturation and conversion to fibrous state. The protein fibres form a reticulum which holds milk fat. This changes milk into curd or yoghurt. .

9 Can you attempt building models of bio molecules using commercially available models (ball & stick models)

     Yes, provided balls of different size & colours are available.

10. Attempt titrating an amino acid against a weak base & discover the number of dissociating (ionisable/functional groups in the amino acid.

     PH of amino acid is recorded. The weak base is slowly added & the Ph recorded continuously. The number of inflexions indicate the number of Ionisable functional groups – coat in the acidic range and – NH2 in the alkaline range.

11. Draw the structure of amino acid alonine


                        H   ______C_______COOH



12. What are gums made of? Is fevicol different?

     Gums are sticky break down products of plant cell walls consisting of polysaccharides and pectin which exude from the wounds in the bark. They are generally water soluble.

     Fevicol is synthetic sticky substance called resin. Resins are insoluble in water.

13. Find out a qualitative test for proteins, fats & oils, amino acids and test any fruit juice saliva, sweat and urine for them.

Test for protein = Biuret test, xanthoproteia test.
Test for fat Oils = Sudan III
Test for Amino Acid = ninhydrin test

14.  Find out how much cellulose is made by all the plants in the biosphere and compares it with how much of paper is manufacture by man and hence what is the consumption of plant material by man annually. What is loss of vegetation?

     About 85 billion tonnes of cellulose is formed annually in the biosphere (out of 170 billion tones of total organic matter). Paper making consumes roughly 0.5 billion tonnes of wood food grains constitute 1.5 billion tonnes. Full wood required is 2 billion tonnes. The increase in consumption of cellulose has resulted in great loss of vegetation.

15. Describe the Important properties of enzyme.

     1. They are hydrophilic & form hydrosol in the free state

     2. They have molecular weight of 6000 to 9,600,000

     3. They do not start a chemical reaction but increase the rate of chemical reaction.
     4 .They do not change the equilibrium but bring out the equilibrium very soon

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