DNA STRUCTURE AND ITS FUNCTIONS BY MD SAQLAIN UMAR.pptx

DNA STRUCTURE AND ITS FUNCTIONS FOR MENTORS MENTE TOPIC IN UNIVERSITY SEMESTER FOR MEDICAL STUDENT AND BIO CHEMISTRY AND BIO MICROBIOLOGY STUDENT.

1. SISTER NIVEDITA UNIVERSITY NAME:- MD SAQLAIN UMAR ENROLLEMENT ID:- 2311225005028 REGISTERATION ID:- 230050281771 STREAM :- BACHLOR SCIENCE IN OPERATION THEATRE TECHNOLOGY DEPARTEMENT:- ALLIED HEALTH SCIENCE TOPIC:- DNA STRUCTURE & IT’S FUNCTIONS. DATE:- 30/04/2024

2. DNA STRUCTURE AND IT’S FUNCTIONS

3. Contents :- INTRODUCTION DISCOVERY OF DNA’S EXISTENCE FUNCTION OF DNA DNA STRUCTURE DNA BACKBONE THE WATSON & CRICK MODEL BASE PAIRING OF DNA DNA REPLICATION CONCLUSION ACKNOWLEDGEMENT. SUBMITED TO MRS. DOYAL PATRA

4. INTRODUCTION:- Deoxyribonucleic acid (DNA) is a molecule that carries the genetic instructions. A polymer of Deoxyribonucleotides. Found in the cells of all living organisms. DNA contains all the genetic information that makes you who you are. Every individual organisms having unique DNA like a fingerprint. Miescher discovered ‘Nucleic’ (DNA) in the cell from Pus in 1869. James D. Watson and Crick are the co-originators of double helix model of DNA. The discovery of DNA was the most important event in biological science of the 20 th century. Deoxyribonucleic Acid is double standard molecules that encodes the genetic information.

5. DISCOVERY OF DNA’S EXISTENCE MIESCHER:- While studying white blood cell in 1869, He isolated a previously unknown type of molecule that was slightly acidic and contained a high percentage of phosphorus. These molecules eventually became called DNA. At the time, these molecules was not thought to be the carrier of Hereditary information because it was believed to lack the variability necessary to account for the incredible diversity among organisms.

6. FUNCTION OF DNA:- It codes for the proteins which are important for metabolic and structural function of the cell. It provides genetic information for protein synthesis and trait information. Transmits the genetic information to the next generating (Children/offsprings). Stores information (Ex, eye color, Blood type ,etc.). Provides a template for its own replication and thus maintenance of genotype and for the Transcription. DNA’S protein, are very important molecules in our cells. Some proteins involved in structural support, while others are involved in bodily movement and defense against germs.

7. DNA STRUCTURE :- The DNA molecules is two spiral , wrapped around each other. A spiral is called a "Helix”. DNA is a double helix. DNA’s shape is sometimes referred to as a ‘twisted ladder’. Both strands of the double-stranded structure store the same biological information. This information is replicated as when the 2 strands separate. DNA Strands are antiparallel. There are 2 parts to the DNA molecules. A “Backbone” running along the outside of the “Ladder”. Bases sticking out sideways from the “Backbone”. DNA is a double stranded molecules consists of 2 polynucleotide chains running in opposite directions.

8. DNA BACKBONE :- The Backbone of DNA (The sides of the ladder is made of alternating molecules). Phosphate Sugar: Deoxyribose. The DNA Backbone is absolutely 100% Identical in every single living organisms on the face of earth. computer, the and plants all have ‘phosphate-sugar-phosphate-sugar…etc. The DNA Backbone is resistance to cleavage. DNA is made up of millions of tiny subunits(monomers)called nucleotides. Each nucleotides consists of three parts Pentose sugar(deoxyribose) Phosphate group Nitrogenous bases Adenine Cytosine Guanine Thymine Here is where biological information is stored. Like the binary code of 0’S and 1’s in computer, the order of the A,T,C,orG’s in the DNA stores information.

9. THE WATSON &CRICK DNA MODEL:- Watson & Crick:-Made physical models to narrow down the possibilities and eventually creates an accurate model of the DNA molecules.Propeosed the double helical structure of the DNA in 1953 using Franklins Pictures. DNA is composed of 2 chains of nucleotides that from a double helix shape. The backbone is formed by covalent bonds between the sugar of one nucleotides and the phosphate group of the next. The backbone has directly directionality (polarity). 5’ end :- Phosphate end 3’ end :-Sugar end. The two strands are antiparallel (the run side by side in opposite direction). Each base will only bond with other specific bases(A=T,C=G).Hydrogen bonds are formed between the bases. These are fairly weak bonds. Having just enough force to hold the two strands of DNA together. DNA strands have to be able to separate easily to functions.

10. BASE PAIRING OF DNA:- Each side of the DNA strand forms a “complementary "hydrogen bond to the other sides. A must always opposite to T. C must always opposite to G. There is hydrogen bonding between the basses.2H-bonds between A and T and 3H-bonds between C and G. It connects bases one polynucleotide chain (nucleotide polymer) with complementary bases of another chain. The importance of such complementary base pairing is that each strands of DNA can act a template to direct the synthesis of other strand similar to its complementary one. The information carried by DNA and RNA direct the synthesis of specific proteins which controls most cellular activities. Thus nucleic acids are unique capable of directing their own self replication.

11. DNA REPLICATION:- Replication of DNA molecule is semi-conservative which means that each parent strands serves as a template for a new strand and that the two new DNA molecules each have one old one new strands. DNA replication requires:- A strand of DNA to serve as a template. Substrates-deoxyribonucleoside triphosphate,(dATP,dGTP,dCTP,dTTP). DNA polymerase :-an enzyme that brings the substrates to the DNA strand templates. A source of chemical energy to drive this synthesis reaction. Nucleotides are always added to the growing strand at the end (end with free-OH group). The hydroxyl group reacts with the phosphate group on the 5’C of the deoxyribose so the chain grows. Energy is released when the bound linking 2 of the 3 phosphate groups of the deoxyribonucleoside triphosphate breaks. Remaining phosphate group becomes part of the sugar phosphate backbone. Step 1:- Unwinding and exposing strand. Step 2:-Priming the strands. Step 3:-Strand elongation. Telomerase.

12. CONCLUSION:- Each strands of a DNA molecules is composed of a long chain of monomer nucleotides. The nucleotides of DNA consists of a deoxyribose sugar molecule to which is attached a phosphate group and one of four nitrogenous bases:- two purines (Adenine and Guanine) and two pyrimidines (Cytosine and Thymine). The nucleotides are joined together by covalent bonds between the phosphate of one nucleotides and the sugar of the next, forming a phosphate-sugar backbone from which the nitrogenous bases produce.one strand is held to another by hydrogen bonds between the bases.Recombination which leads to rearrangement of genes takes advantages of the ability to form an unusual structure called a Holliday’s structure.Also different kind of mutations occur as a result of specific DNA structure etc.

13. ACKNOWLEDGEMENT:- I am very much pleased to submit my seminar topic on DNA STUCTURE &IT’S FUNCTIONS for Bachelor science honor in Operation Theatre Technology 2 nd year semester. I sincerely thanks to our Mentors Mrs. Dayal Patra to give me opportunity for preparing the seminar topic and our (HOD)Mr. Sanjay Das and Ankita Chakraborty(Bio Chembion microbiology). department of Allied Health Science. And also Mr. Siddhartha Dutta of Biology Department of our university for guiding properly the same. I also thankful to our other respected teachers of the department of Allied Health Science and our friends and parents for supporting me to help to make the seminar on the above topic.

14. THANK YOU MD SAQLAIN UMAR BY