1.
Differentiate reducing and non reducing sugar
2.clssify the carbohydrate based on hydrolysis
3.Define Glycosidic linkage.
The two monosaccharides are joined together by an oxide linkage formed by the loss of water
molecule.
4.Explain hydrolysis product and Glycosidic linkage of Disaccharide and polysaccharide.
5.Write the product glucose reacts with HI [OR]
How do you explain the presence of all the six carbon atoms in glucose in a straight chain?
n-hexane formation.
6.How do you explain the presence of five
OH groups in glucose molecule?
Glucose reacts with hydoxyl amine and forms an oxime
Glucose reacts with hydrogen cyanide and forms glucose cyanohydrin
7.How do you explain the presence of an aldehydic group in a glucose molecule?
Glucose undergoes oxidation and forms gluconic acid.
8.Draw the Fischer projections of glucose.
9.Draw Haworth projections of glucose
10.Draw Haworth projections of Fructose.
11.Define the following term: Anomers
The pair of stereoisomers which differ only in the configuration of the hydroxyl group at C1 are
called anomers.
11.How do you explain the absence of free aldehyde group in the glucose?
Or
Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.
*Glucose doesnot give schiff's test
*Does not form addition product with NaHSO3
*The pentaacetate of glucose doesnot react with hydroxlamine indicating absence of -CHO
group.
12.Define invert Sugar .
Sucrose is dextrorotatory
On hydrolysis it gives dextrorotatory glucose and laevorotatory fructose.
The laevorotation of fructose (-92.40) is more than dextrorotation of glucose.(+52.50 ) so a
change in the sign of rotation from dextro (+) to laevo (-).
13.Comment on starch
Polysaccharide of plants
Made up of two parts Amylose Amylopection
Amylose Amylopection
Water soluble Water insoluble
15-20% Starch 80-85% Starch
Unbranched chain Unbranched
C1-C4 Glycosidic C1-C4 Glycosidic linkage.
Branching C1-C6
Glycosidic linkag
14.Define amino acids
Amino acids contain amino(-NH2 ) and carboxyl(-COOH) functional groups.
14. Explain two types of amino acids.
Essential amino acids:
* Cannot synthesised in the body.
*Must obtained through diet
*Eg: Leucine and Iso leucine
Non-Essential amino acids:
Can be synthesised in the body.
Need not depend on diet
Glycine Alanine Glutamic acid.
15.Amino acids are Amphoteric in nature. How?
OR Explain Zwitter ion
In aqueous solution the carboxyl group can lose a proton and amino group can accept a proton,
giving rise to a dipolar ion known as zwitter ion.
This is neutral but contains both positive and negative charges
Zwitter ionic form react both acids and bases
26. Define Peptide linkage.
Peptide linkage is an amide formed between
-COOH group and -NH2 group. This results in the elimination of water molecule and formation
of peptide bond-CO-NH
27. Write the difference between Globular protein and fibrous proteins.
Eg. Keratin in water Albumin in eggs
28.What is denaturation of protein.
When a protein in its native form is subjected to a change such as change in temperature or
change in pH, the hydrogen bonds are disturbed. Due to this globules unfold and helix get
uncoiled and protein loses its biological activity. This is called denaturation of protein. During
denaturation secondary and tertiary structures destroyed but primary structure remains intact.
example coagulation of jeg while on boiling curdling of milk.
29. Name the type of Nucleic acids.
DNA and RNA
30.Name the constituents of nucleic acids
*Pentose sugar * Phosperic acid *Nitrogenous bases
31.Write the important structural and functional differences between DNA and RNA
32.Name the bases which present in SNA and RNA
DNA: Adenine Guanine Cytosine and Thymine
RNA: Adenine Guanine Cytosine and Uracil.
32. What are different types of RNA found in the cell?
RibosomalRNA
MessengerRNA TransferRNA
33. Glucose or sucrose are soluble in water but cyclohexabe or benzene are insoluble water.
Why?
Glucose -5OH sucrose -8OH
They form extensive hydrogen bonding with water. But cyclo hexane and benzene not possible
to form hydrogen bond.
34.How do you explain the absence of aldehyde group in the pentaacetate of
D-glucose?
Pentaacetate of D-glucose in aqueous medium does not form open chain structure and thus
when it reacts with NH2OH, it does not form oxime indicating that there is absence of free
aldehyde group.
35.The melting points and solubility in water of amino acids are generally higher than that of the
corresponding halo acids. Explain.
The amino acids exist as zwitter ions.
Because of this dipolar salt like character they have strong dipole-dipole attractions.so melting
point is higher.Halo acids which donot have salt like character.
36.Where does the water present in the egg go after boiling the egg?
On boiling the egg the proteins undergo denaturation.
water absorbed by the coagulated protein through H-bonding.
37.Why cannot vitamin C be stored in our body?
Vitamins C is water soluble.so readily excreted in urine.
38.Carbohydrates are optically active. Why?
Carbohydrates have chiral or asymmetric carbon
39. What are biocatalyst?
Enzymes are biocatalyst.
40. What type of bonding helps in stabilizing Alpha helix structure of proteins?
Inter molecular Hydrogen bonding.
40.write the difference between nucleoside and nucleotide.
