molecular biology DNA and RNA presentation

DNA and RNA

1. DNA AND RNA DONE BY DR AYA ALII

2. MOLECULAR BIOLOGY DEFINATION Molecular biology  is a branch of  biology  that seeks to understand the  molecular  basis of biological activity in and between  cells , including  biomolecular  synthesis, modification, mechanisms, and interactions

3. SOME IMPORTANAT DEFINETION genome : genatic material of organism _ gene : part of dna that code for synthesis of single poly peptide _ polypeptide : polymer of amino acid that form protein _ codone :three successive nucleotide base that code for single pro _ intron : three successive nucleotide that dose not encode any amino acid _ exon :sequence of codon which code number of amino acid _ promoter :sequence of bases in dna near the start of the gene very important in rna transcription _ cds : portion of the dna composed of exon that code for protein

4. DNA DNA IS ABLUEPRINT OF LIFE . _DNA contain structure of protein synthesis in the cell _ dna is amolecules that carries the genetic instruction used in growth development ,functioning reproduction of all known living organism and many viruses _one strand on dna in one chromosome can be up to 245 million base pair long _human have 46 chromosomes

5. Impotance of DNA It central importance to all life on earth _medical benefit such as cure for diseases _better food crops _healing and regeneration _growth and development

6. Chromosome It has been estimated that if all dna from just one cell of human body was untwisted it would stretceh about 6 feet _it mean that dna in one cell is about 100000 time longer than the cell it self _its all present in cell that represent 10% of cell volumes

7. _ Chromosomes are found in the nucleus of every cell of our body and are made up of DNA, tightly coiled around proteins. We have 23 pairs of chromosomes altogether, and they can only be easily observed during cell division . _ chromosome thread like structure of nucleic acid and protein _ chromatid each of two thread like strand into which chromosome divide longtodinally during vell devesion connected to each other by centromere _ chromatin the material of which the chromosome of organism are composed consisting of dna and rna and protein

8. Dna component 1- suger both dna and rna are composed of 5 carbon suger the carbon on suger are numbered from one to five suger molecule made up of C,H,O2 with molecule formuls CH2O suger is closed to form ring structure 2_ phosphate group link the 3 end of one nuvleotide to the 5 end of the next by phosphor di_ ester bond 3_ nitrogen base attached to carbon no 1 are two classes purines ( adeninr and guanine )and pyrimidines ( cytosine and thyamine )

9. Building of nucleotide The suger is the central component of the nucleotide _ the phosphate is attached to carbon number 5 of the suger _the nitrogen base is attached to carbon number 1 _nucleotide within dna are connected by covalent bond _ two dna strand are connected by hydrogen bond between nucleotides A=T (DOUBLE BOND ) C=G ( TRIPLE BOND )

10. BULIDING OF POLYMER _NUCLEOTIDE JOINED TOGETHER TO FORM POLYMER BY PHOSPHATE GROUP BOND COVALENTELY WITH CARBON NO 3 IN SUGER _HYDROEN BONDBETWEEN PHOSPHATE GROUP CAUSE DNA TO TWIST _ BULIDING OF NUCLEOSOME _ dna coil tightly around protein called histone -histone with phosphate bond together to form nucleosome

11. DNA REPLICATION TRANSCRIPTION : the process by which the information in one strand of dna is copied into new molecules of messenger rna _ translation :occur in ribosomes when masenger rna translated into protein _DNA REPLICATION STEP 1) INTIATION 2)SYNTHESIS 3) TERMINATION 4) POST REPLICATIVE MODIFICATION OF DNA

12. 1) INTIATION PROCESS OF DNA Process begin at site origin of replication _ first step to separate the two strand of dna by enzymes called helicase enzymes result in formation of dna fork _two strand each provide atemplete for new strand _an enzymes called primase start the process _this enzymes make asmall piece of rna called primer that marking starting point for construction of the new strand of dna _the enzymes called polymerase bind to the primer and will make the new strand of dna from 5 to 3 _ single strand dna protein attached to dna strand to prevent rewinding of dna

13. Synthesis phase Begin when rna primer with polymerase enzyemes add bases from 5 to 3 called leading phase _the other strand the lagging strand cannot be made contioniously because it run in opposite direction _ the dna polymerase can make this strand in form of small fragement called okzaki fragement _ dna polymerase the add ashort row of dna bases in the 5 to 3 direction

14. Comparison between leading and lagging _ from 3 to 5 prime _ contionous synthesis _one rna Lagging strand From 5 to 3 _ dicontious synthesis _many rna prime Leading strand

15. termination Once the dna strand has been made the enzyes called exonuclease remove all rna primer from both strand _ onather polymerase enzymes fill in the gap that are left behind dna _finally the dna ligase enzymes seal the fragment of the dna in both strand to form continuous duble strand

16. Type of RNA MRNA _ encode all information nessary for synthesis of polypeptide of protein intermediate carrier of genatic information deliver genatic material to cytoplasm TRNA CARRY AMINO ACID TO THEIR POSITION ALONG MRNA TEMPLETE TO BE ADDED BY GROWING POLYPEPTIDE CHAIN Rrna _the central component of ribosome _it provide mechanism of decoding mrna into amino acid

17. COMPARISON BETWWEN DNA AND RNA DNA DEOXY RIBONUCLEIC ACID _LONG TERM STORAGE OF GENATIC INFORMATION _ TRANSIMITE OF GENATIC MATERIAL TO MAKE OTHER CELL AND NEW ORGANISM RNA RIBO NUCLEIC ACID _ USED TO TRANSFORM THE GENATIC MATERIAL TO THE CYTOPLASM _MAY BE THE MOLECULES USED TO STORE GENATIC MATERIAL IN PRIMATIVE FORM

18. COMPARISON BETWWE DNA AND RNA DNA _ DNA B FORM DOUBLE HELIX _ dna is double stranded molecules consisit of long chain of nucleotides _composition deoxyribose SUGER phosphate group nitrogenous base adenine guanine cytosine thyamine RNA A FORM HELIX _ Sdingle strand helix consist of shorter chain of nucleotides _composition phosphate group AND RIBOSE SUGER nucleotide base adenine guanine cytosine uracil

19. Comparison betwwen DNA AND RNA DNA SELF REPLICATING _ BASES PAIR ( AT) ADENINE –THYAMINE (GC) GUANINE – CYTOSINE _ REACTIVITY : C-H BOND MAKE IT MORE STABLES _ BODY DESTROY ENZYMES THAT ATTACK IT _ SMALL GROOVES IN HELIX ACT AS PROTECTION FOR DNA RNA SYNTHESIS FROM DNA _ BASES PAIR (ADENINE -URACIL) (GUANINE –CYTOSINE ) _ REACTIVITY : O-H BOND MAKE IT MORE REACTIVE _ NOT STABLE UNDER ALKALINE CONDITION _ LARGE GROOVE MAKE IT MORE PRON TO ENZYMETIC ATTACK

20. DNA SUCCETIPLE TO UV DAMAGE TRANSCRIPTION RNA RESISTANCE TO UV DAMAGE TRAANSLATION

21. PROTEIN MOLECULES THAT SUPPORT GROWTH OF THE BODY DIVIDED INTO ESSENITIAL AMINO ACID :obtain from protein reach food as meat _ non essential protein :synthesis naturally in your body TYPE OF PROTEIN 1)PRIMARY : SEQUENCE OF CHAIN Of amino acid 2)secondary :chain of amino acid linked by hydrogen bond 3) teriary :occur when certain attraction occur between alpha helics and pleated sheet 4) quaternary :protein containing more than chain of amino acid

22. Protein synthesis Intiantion : mrna enter cytoplasm and become assossiated with ribosomes trna each carry specific amino acid pair up with mrna codon iside ribosome paring of a-u and g-c between mrna and trna determine the order of amino acid in protein

23. Elongation phase Addition of aminoacid one by one _as the ribosomes move along the mrna each trna transfer its amino acid to the growing chain producing p rotein TERMINATION PHASE _ when the ribosome hit stop codon ribosome stop protein synthesis