CBSE Guess > Papers > Important Questions > Class XII > 2007 > Chemistry > Biomolecules

Biomolecules

1. What are reducing and non-reducing sugars? What is the structural features characterising reducing sugars?
2. Explain mutarotation. Give its mechanism in the case of D-glucose
3. Give reasons for the following.
   (i) Amino acids have relative higher melting points as compared to corresponding halo acids.
   (ii) Amino acids are amphoteric in behavior.
   (iii) On electrolysis in acidic solution amino acids migrate towards cathode while in alkaline solution these migrate towards anode.
4. What type of linkages are responsible for the formation of,
   (i) Primary structure of proteins.
   (ii) Cross linking of polypeptide chains.
5. What is denaturation and renaturation of proteins?
6. What are the products obtained on complete hydrolysis of DNA?Write down the structures of pyrimidine and purine bases present in DNA.
7. Enumerate the structural differences between DNA and RNA. Write down the structure of a nucleoside, which is present only in DNA.
8. What are complementary bases? Draw structure to show hydrogen bonding between adenine and thymine and between guanine and cytosine.
9. What is the melting temperature (Tm) of DNA? A DNA molecule with more number of GC base pair than AT base pairs has higher Tm than one with lesser number of GC base pairs than AT base pairs. Why?
10. How does DNA replicate? Give the mechanism of replication? How is the process responsible for preservation of heredity?
11. Answer the following about protein synthesis
    i) Name the location where protein synthesis occurs.
    ii) How do 64 codons code for only 20 amino acids?
    iii) During translation which one of the two-end functional groups of the polypeptide is formed first?
12. How are lipids classified? Give an example of each class.
13. Name the deficiency diseases caused due to lack of vitamin A, C, E, B₁, B₁₂, B₆ and K.

1. Atomic Structure and Chemical Bonding
2. Solid States
3. Solutions
4. Thermodoynamics
5. Chemical Kinetics
6. Nuclear Chemistry
7. Polymers
8. Biomolecules
9. Chemistry In Every Day Life