DNA and RNA types and functions

DNA and RNA types and functions

1. Dna & Rna types and function Subhananthini Jeyamurugan , 18py17, M.Sc., microbiology. Ayyanadar Janaki ammal college Sivakasi.

2. • There are two kinds of nucleic acids in cells: 1) ribonucleic acids (RNA) 2) deoxyribonucleic acids (DNA) • Both RNA and DNA are polymers built from monomers called nucleotides . • A nucleotide is composed of: – a base, a monosaccharide, and a phosphate. Nucleic Acids

3. Nucleic Acids • made up of nucleotides • found in all living cells except RBC • deoxyribonucleic acid (DNA) and ribonucleic acid (RNA ) • DNA is in the nucleus • RNA is in the cytoplasm • function in the storage and transmission of genetic material •And control and direct all protein synthesis

4. -each nucleotide contains 1 ) a sugar 2) a base 3) phosphoric acid unit

5. Bases in Nucleic acids There are two types of bases such as Purines and Pyrimidines . Purines are Adenine and Guanine. Pyrimidine is are cytosine, thymine and uracil. Bases for DNA: A- Adenine, G- Guanine, C-Cytosine and T - Thymine Bases for RNA: A- Adenine, G- Guanine , C-Cytosine and U- Uracil

6. Purine and pyrimidine structure Purines Pyrimidine

7. Formulation of Nucleicacid Altering phosphate, sugar molecules form the backbone. Phosphate and sugar forms an ester bond with the removal of water. The sugar bonds with a base, forming tertiary amine, with the removal of water.

8. DNA and RNA strand The sequence of the bases in DNA or RNA form the Primary Structure.

9. Structure of DNA

10. The nucleotide bases align the DNA

11. DNA structure Secondary structure: The ordered arrangement of nucleic acid strands. the double helix model of DNA secondary structure was proposed by James Watson and Francis Crick in 1953. Double helix: A type of secondary structure of DNA in which two polynucleotide strands are coiled around each other in a screw- like fashion.

12. Watson and crick

13. The dna double helix 3D structure of a DNA double helix.

14. Dna DOUble helix Like a spiral stair case: the phosphate sugar backbone represents the hand rail. The bases represent the steps. Hydrogen bonding presents between the bases For DNA: A bonds with T C bonds with G For RNA: A bonds with U C bonds with G

15. base pairing

16. What is histones? DNA is coiled around proteins is called as Histones. Histones are rich in the basic amino acids Lys and Arg , whose side chains have a positive charge. The negatively- charged DNA molecules and positively charged histones attract each other and form units called nucleosomes.

17. What is Nucleosome? A core of eight histone molecules around which the DNA helix is wrapped. Nucleosomes are further condensed into chromatin. Chromatin fibers are organized into loops, and the loops into the bands that provide the super structure of chromosomes.

18. Chromosomes

19. To accommodate the large amount of genetic material, DNA in the nuclei cells is coiled around proteins called Histones.

20. DNA and RNA • The three differences in structure between DNA and RNA are: – DNA bases are A, G, C, and T; the RNA bases are A, G, C, and U . – The sugar in DNA is Deoxy ribose ; in RNA it is ribose. – DNA is always double stranded; there are several kinds of RNA, most of which are single-stranded.

21. RNA RNA molecules are classified according to their structure and function.

22. What is GENEs? A Gene is a segment of DNA that carries a base sequences that directs the synthesis of a particular protein, tRNA or mRNA. There are many genes in one DNA molecule.

23. What is introns and exons? Exons A section of DNA that, when transcribed, codes for a protein or RNA. Introns A section of DNA that does not code for anytihng functional.

24. Structure of transfer RNA

25. TRANSFER RNA Each tRNA is specific for only one amino acid . an amino acid binds to an OH group of the Suitable tRNA by an Ester bond. At the opposite end of the tRNA molecule is a codon recognition site. The codon recognition site is a sequence of three bases called an anticodon . This triplet of bases aligns it self in a complementary style to the codon triplet on mRNA

26. RNA in translation mRNA, rRNA, and tRNA all participate in translation. Protein synthesis takes place on ribosomes. A ribosomes dissociates into larger and a smaller body. In higher organisms, the larger body is called a 60S ribosomes: the smaller body is called a 40S ribosome. together the 40S and 60S ribosomes form a unit on which mRNA is stretched out. Triplets of bases on mRNA are called codons. The 20 amino acids are then brought to the mRNA ribosome complex, each amino acid by its own particular tRNA.

27. translation Process whereby a base sequences of mRNA is used to create a protein The m RNA leaves the nucleus and binds with ribosomes in the cytoplasm. Transfer RNA (tRNA) contains and anticodon, which is a 3 bases sequence that is complementary to the codon on the mRNA tRNA also carries an amino acid The codon of the mRNA determines the amino acid sequence.

28. 3d structure of the transfer RNA

29. Protein synthesis

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