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