3 Biology -- Genetic Materials

What are sense and anti -sense strand?

1 Answers

Sense strands: It is a coding strand which carries translatable code directed in the 5' to 3' direction and contains codons.

Anti sense strand: It is complementary strand to the sense strand which is non coding strand and contains anti-codon.

Who isolated nucleic acid for the first time ?

Friedrich Mascher(Fritz)

Name all the types of bond that make up the DNA?

Ester bond (between phosphate and 5′OH of deoxyribose sugar.)

Glyosidic bond (between deoxyribose sugar at its 1st Carbon and the adjacent nitrogenous base.)

Double (betweenadenosine and thymine) or triple hydrogenbond(between guanine and cytosine )

Diester bond (between 5′phosphate of one nucleotide to 3′carbon of deoxyribose sugar of next nucleotide.)

Why elongation of nucleic acid chain during replication time, always starts from 3' position ?

What is the sole reason for anti- parallel nature of DNA?

Because it ensures hydrogen bonding between the nitrogenous bases lying opposite to each other.

List all the enzymes that are requisites of DNA replication? Also mention their respective roles?

Enzymes for DNA replication with roles :

Endonuclease: nicking

Helicase : breaking hydrogen bond

Phosphorylase : activation of phosphate group

Topoisomerase: release pressure during fork formation

Ligase : joining fragments

RNAse : help in okazaki fragment formation

Restriction endonuclease: checking

Difference between DNA & RNA ?

Describe Mechanism of Semi - Conservative Method of DNA Replication ?

Process of semi-conservative mode of replication of DNA:

The mechanism of DNA replication is a complex and involves many steps. The steps are:

1) Initiation of DNA replication

2) Activation of deoxyribonucleotides

3) Exposure of DNA strands or nitrogen bases and formation of Y-shaped fork

4)Formation of RNA primer

5) Base pairing

6) Formation of new DNA strands

7)Proof-reading and DNA repair

8)Termination of DNA helix formation.

1)Initiation of DNA replication-

The point in the DNA from where...

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