The nucleic acids
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Transcript of The nucleic acids
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
The Nucleic Acids
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Nucleic Acid
a complex organic substance present in living cell esp. DNA & RNA whose molecules consist of many nucleotides linked in a long chain.
Functions:
• Transmission of hereditary characters.
• Synthesis of proteins.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Components
A. Kinds of Nucleic Acid
1. RNA (Ribonucleic acid) – it is located elsewhere in the nucleus and in the cytoplasm.
2. DNA (Deoxyribonucleic acid) – it is located in the chromosomes of the nucleus.
Nucleotides – building blocks of nucleic acid chain. It is composed of base, sugar and phosphate.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Base
• Base found in DNA & RNA are basic because they are heterocyclic amines.
• Two of these bases (adenine and guanine) are purines and the other three (cytosine, thymine & uracil) are pyrimidines.
• DNA bases: A, G, C & T while RNA: A, G, C & U.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Purines
Adenine
Guanine
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Pyrimidines
Cytosine ThymineUracil
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Sugar
• Sugar component of RNA is ribose; DNA is deoxyribose.
• The combination of sugar and base is known as nucleoside.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid Base Sugar Nucleoside
Adenine Deoxyribose Deoxyadenosine
Adenine Ribose Adenosine
Guanine Deoxyribose Deoxyguanosine
Guanine Ribose Guanosine
Cytosine Deoxyribose Deoxycytidine
Cytosine Ribose Cytidine
Thymine Deoxyribose Deoxythymidine
Uracil Ribose Uridine
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Phosphate
• This are phosphoric acid that when this group is linked to the –CH2OH group of nucleoside the result is a compound known as nucleotide.
• Sequence:
Nucleotide=base+sugar+phospate
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid Base Nucleoside Nucleotide
Adenine Adenosine Adenylate (AMP)
Adenine Deoxyadenosine Deoxyadenylate (dAMP)
Guanine Guanosine Guanylate
Guanine Deoxyguanosine Deoxyguanylate
Cytosine Cytidine Cytidylate
Cytosine Deoxycytidine Deocycytidylate
Uracil Uridine Uridylate
Thymine Deoxythymidine Deoxythymidylate
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
AMP(Adenosine
Monophosphate)
ATP(Adenosine
Triphosphate)
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
DNA & RNA
Components DNA RNA
Location Nucleus Nucleus & Cytoplasm
Bases A, G, C & T A, G, C & U
Sugar Deoxyribose Ribose
Structure Double helix Many structure
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Structures
1. Primary structure
• Divided into parts:
a. Backbone of molecule – consist of alternating deoxyribose and phosphate groups.
b. Side-chain groups – consist of the bases that are linked one to each sugar unit and carry all information necessary for protein synthesis.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Primary Structure
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid 2. Secondary structure (Double helix)
• In 1953, James Watson & Francis Crick established the 3D structure of DNA.
• The model of DNA established by watson and crick was based on two important pieces of information obtained by other workers: (1) the chargaff rule that (A&T) and (G&C) are present in equivalent quantities. (2) X-ray diffraction photographs obtained by Rosalind Franklin and Maurice Wilkins.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid• Watson and Crick concluded that
DNA is composed of two strands in double helix.
• In the DNA double helix the two polynucleotide run in opposite directions in 5’ to 3’.
• The sugar-phosphate backbone is on the outside and bases are point inward.
• The bases are paired according to chargaff rule. The bases so paired form hydrogen bonds with each other thereby stabilizing the double helix. They are called complimentary base pairs.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid Double Helix
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
The Central Dogma
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic AcidReplication
• The process begins when a helicase (specialized enzyme) will unzip the DNA double helix into two strands which is the leading and lagging strand.
• The leading strand has a 5’ to 3’ direction and direct synthesis of a new strand of DNA through complimentary base pairing. The old strand then unites with the new strand to reform a double helix through the process of semiconservative replication.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid • In the lagging strand, the synthesized of DNA strand is in a short segments in a 3’ to 5’ direction. Thus, this short segments placed on the lagging strand are okazaki fragments and are ultimately joined by the enzyme DNA ligase to form a new strand.
• Therefore, two new DNA strand is being replicated.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic AcidTranscription
1. Initiation Stage
there is a special region on the DNA wherein RNA polymerase attached and this is called the promoter site.
2. Elongation Stage
certain proteins called transcription factors unwind the DNA strand and allow the RNAQ polymerase to transcribed only a single strand of DNA to a strand of RNA called mRNA.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid • Antisense strand – strand that serve as the template.
• Sense strand – strand that is not transcribed.
3. Termination Stage
RNA polymerase moves along the DNA strand until it reaches a terminator sequence at the point RNA polymerase releases the mRNA polymer and detaches from the DNA. The DNA strand will bind again.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic AcidTranslation
1. Initiation stageThe small ribosomal subunit enters in
the methylated cap of the mRNA and goes to the initiation site. The tRNA contains anti-codon (UAC) which is complimentary to the mRNA codon (AUG) which will bind. The large ribosomal subunit will bind to small ribosomal subunit to peptidyl site and aminoacyl site. The 1st tRNA will occupy the p-site and 2nd tRNA (AAA) will enter the A-site which is complimentary to 2nd mRNA (UUU) codon.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid 2. Elongation Stage
The methionine then transferred to A-site amino acid. The 1st tRNA exits and ribosomes move along the mRNA. The 3rd mRNA enters. The process will just continue. As the elongation continues the growing peptide is continuously transfer to A-site tRNA. Ribosomes move to mRNA and new tRNA enters.
3. Termination stage
When stop codon encountered in the A-site, release factor enters the A-site and translation is terminated. The ribosomes dissociates and newly form protein release.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic AcidMutation and Cloning
Mutation – an error in the copying of a sequence of bases.
Occur during replication and it can be classified as microlesion and macrolesion.
a. Microlesion – involving the replacement of one base pair by another (Substitution).
it divided into three subclasses:
1. Transition 2. Transversion 3. Frame-shift
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid • In the transition, the replacement of purine by another purine or a pyrimidine by another pyrimidine.
• In the transversion, the replacement of a purine by a pyrimidine or vice versa..
• In the frame-shift, the loss or addition of one of few pairs of bases.
b. Macrolesion – classified as deletions, duplication and rearrangement.
• In deletions is the inability to revert.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid • Mutagens – chemicals that can cause mutation.
Urethane
Lead
Dimethylnitrosoamine
Diethylnitrosoamine
Hydroxylamine
Hydrazine compound
Nitrosoamides
Acridine orange
benzopyrene
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid Cloning
• Cloning is the process of creating genetically identical copies of biological matter.
Types of Cloning:
1. Molecular Cloning
Molecular cloning focuses on making identical copies of DNA molecules. This type of cloning is also called gene cloning.
2. Organism Cloning
Organism cloning involves making an identical copy of an entire organism. This type of cloning is also called reproductive cloning.
3. Therapeutic Cloning
Therapeutic cloning involves the cloning of human embryos for the production of stem cells. The embryos are eventually destroyed in this process.
Structure
DNA & RNA
Mutations
Central Dogma
Nucleic Acid
Thank You!
Presented by:
Den Mark Galapir
Xandrad Abigail Garduque
Edmar Luban
Jovilyn Padilla
Jessa Marie Ipac