The important points on DNA Polymerase I are exclusively depicted in this Presentation. The roles and functions of DNA Pol I during the Molecular processes are discussed. {Every year, January 24th is observed as the National Girl Child. It is the responsibility of everyone of us to bring awareness about the Girl child. Every Girl must be given proper Nutrition, proper Education, proper encouragement in the studies, Sports and Cultural activities. One is not supposed to confine the Girl to a Kitchen room. It is the right of every Girl child to get educated and become independent. Dr. APJ Abdul Kalam Sir says, "Education is the most powerful weapon which you can use to change the world". Like that, every Girl must be educated and given a 'weapon'.} {Disclaimer: The images have been downloaded from Google images and used in this video. I thank all the sources, references, and creators of these images. These pictures are used for EDUCATION and fair purpose only}

1. DNA POLYMERASE I

2. Fig: Effect of Polymerase
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3. INTRODUCTION:
• Sir Arthur Kornberg and team purified the DNA Pol I enzyme
from the E. Coli.
• Plays a major role - polymerization of Nucleotides.
• Not only polymerization but also various other functions.
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5. • DNA Pol I performs:
• the Polymerisation activity and
• the Exonuclease activity.
• Etymology:
• ‘Exo’ means ‘Outer side’.
• ‘Nuclease’ means ‘cutting or cleaving the Nucleic acid’.
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7. Q.) Why there are two opposite functions?
A.) To avoid the addition of wrong/error prone
nucleotides. To avoid the Mutations.
Note: Here, the DNA Pol I acts as both the ‘Rule maker’ and ‘Road
maker’!!
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9. • Exonuclease activity of DNA Pol I:-
• 5'-3'
• 3'-5'
• Scientists realized that, DNA Pol I alone cannot synthesise or replicate
such a huge stretch of DNA.
• Hence, they thought that there would be some more enzymes which
take-up this process.
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11. • After discovering DNA Pol-III, Scientists realized that DNA
Pol-I is a helper enzyme in the Replication process and is not
the key enzyme.
• DNA Pol I cleaves off the RNA Primer and replaces with
31-OH after the completion of whole Replication process.
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13. DNA POL I UNIQUE FEATURE:
• It can also acts as RNA dependent DNA Polymerase (not only as the
DNA dependent).
i.e., using RNA as template to synthesise the DNA strand. (but its
efficiency is very very less)
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14. Fig: RNA dependant DNA Polymerase
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