Introductory to Molecullar Biology

8/8/2019 Introductory to Molecullar Biology

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Group 10

Introductory to Molecullar Biology

Rizki Meizikri (1010311010)

Wahyu Tri Novriansyah (1010312013)

Muhammad Farid (1010312041)

Shofi Faiza (1010312069)

Deby Nelsya Eka Putri (1010312097)Muhammad Ihsan Fachruddin (1010313013)

Akbara Pradana (1010313047)

Ghucyka Jhonelta (1010313082)

Afrilizia Putri (1010313095)

Carlven Lenim (1010314010)



ScenarioRiri, 18, read news on the mass media about a terrorist shot todeath by the police. To check the validity of the terrorist·s identity,a DNA test should be done. Riri who is currently learning aboutmolecullar biology is very excited with the news. She recalls her

highschool lesson about DNA·s function which can maintain itscharacteristic through replication process, and mutation mayoccur if DNA is exposed to radiation.

Riri learns from several sources that DNA transcription producesRNA that will be translated in protein synthesis. DNA

recombination, a genetical engineering technique, can also helpproducing stem cell, vaccines, medicines, and even cloning which becomes ethical dilemma.

How do you describe these problems?



Scheme

Biomolekuler

mRNA

Transkripsi

DNA

Replikasi

Replikasi

rRNA

RNA

Translasi

tRNA

Protein

Rekayasa Genetika

Mutasi

Ekspresi

Recombinant

DNA

Cloning Stem Cell

Vaccine



1. Students Able to Explain About

Structure and Function of DNA and

RNA

NitrogenBase

PhosphateGroup

Sugar

Nucleotide

DNA

RNA



Pyrimidines

Thymine (T) Cytosine (C)

Purines

Adenine (A) Guanine (G)



Phosphategroup

Nitrogenous base(A, G, C, or U)

Uracil (U)

Sugar (ribose)

tRNA



Differences Between DNA and RNADifferences DNA RNA

Shape Double Helix Single Strand

Sugar Deoxyribose Ribose

Pyrimidines Cytosine, Thymine Cytosine, Uracil

Function(s) Protein synthesis, Inheritance Protein synthesis

Stability Stabile Less stabile

Location Nucleus Nucleus and Cytoplasm



2. Students Able to Understand Factors

That Affect DNA Stability

y Hydrogen Bonding

y Thermal Melting

y Phosphate bonding

y pH

y

Radiation, ex : UV, infra red, X-Rayy Virus DNA and RNA



3. Students Able to Explain DNA

Replication Process



Parental DNA

DNA polymerasemolecule

Daughter strandsynthesizedcontinuously

Daughter strandsynthesizedin pieces



How Nucleotides Added in DNA

Replication



y Primase enzyme put a primer RNA on the strand

y DNA polymerase III begin adding nucleotides

y

DNA polymerase I transforms the primer RNA to DNAy The replication continues until the end of the strand

Leading Strand



Lagging Strand

Primase enzyme put a primer RNA on the strand

DNA polymerase III begin adding nucleotides

Primase enzyme put another primer RNA on the strand

DNA polymerase III stop its activity and move to the new primerRNA

DNA polymerase III stops when it meets the first primer RNA,leaving the strand unfilled. The blank space is called OkazakiFragment

Primer RNA will be transformed to DNA by DNA polymerase I,so that ligase can bind it with the DNA made by DNA polymeraseIII



4. Students Able to Explain Protein

Synthesis Process

Startcodon

RNA

Transcribed strand

StopcodonTranslation

Transcription

DNA

Polypeptide



RNA polymerase

DNA of gene

Promoter DNA Terminator

DNAInitiation

Elongation

TerminationGrowingRNA

RNA

polymerase

Completed RNA

DNA

RNAtranscriptwith capand tail

mRNA

Exon Intron IntronExon Exon

TranscriptionAddition of cap and tail

Introns removed

Exons spliced together

Coding sequence

NUCLEUS

CYTOPLASM

Tail

Cap



5. Students Able to Explain DNA

Mutation

Types of DNA mutation:

y Missense Mutation

Nitrogen base changed,

amino acid changed (ex:

Sickle Cell Anemia)

y Nonsense Mutation


codon turned into stop codon

y Silent Mutation


amino acid doesn·t change

y Frameshif t Mutation

Abnormal number of

nitrogen base

y Splice Site Mutation

Failure in intron removal



6. Students Able to Explain Genetic

engineering

y Genetic engineering:

y Direct manipulation on organism·sgenetic material in a way that does not

occur under natural conditions

y Goals of genetic engineering:

Improve understanding of how geneswork

Advance biotechnology³themanipulation of organisms to createproducts or cure diseases



y Process of Genetic Engineering

Isolation of theGenes

Constructs

TransformationsSelections

Regenerations Confirmations



What is cloning???y Cloning processes used to create copies of DNA fragments

(molecular cloning), cells (cell cloning), or organisms.

y Three types of cloning:

1. Gene cloning

a process where fragments of DNA aretransferred from one organism to another, usually carried on aDNA vector. Microbes like bacteria are convenient carriers andhosts for cloning DNA.

2. Reproductive cloning

3. Therapeutic cloning

y Basic of gene cloning technologies recombinant DNA



Reproductive and theraputic Cloning



y Recombinant DNA (rDNA) technologies is a genetic

engineering method on biomolecular level.

y Recombinant DNA artificial DNA that is created by

combining two or more sequences on DNA that would normally

occur together through the process of gene splicing.

y Recombinant DNA technologies use enzymes that cleave or copy

DNA in living cells. The purified enzymes can perform DNA

manipulations in vitro in recombinant DNA experiments.



y General Steps in rDNA procedures:

1. The DNA of interest that is to be transferred (also called

foreign DNA, insert DNA, cloned DNA, or transgene) isobtained by first extracting the DNA from the organism and

then cutting out the specific DNA sequence using special

enzymes.

2. The transgene is inserted into a special DNA molecule called acloning vector and joined (by ligation) to produce a new

recombinant DNA molecule (also called cloning vector-insert

DNA construct, or simply DNA construct).

3. The DNA construct is transferred into, and maintained in, a

host cell (bacterium) by the process of transformation. The

vector replicates, producing identical copies (called clones) of

the insert DNA.



4. The host cells that have incorporated the foreign DNA are

identified and isolated from untransformed cells.

5. The cloned DNA can be manipulated such that the proteinproduct it encodes can be expressed by the host cell.



vectorsy Vectors are entities for carrying the target DNA into a host

cell for multiplication or cloning.

y Cloning vectors:

o Plasmid vectors

o Viral vector

o Vectors for very large DNA fragments:

o Cosmids (hybrid of plasmid and bacteriophages)

o Bacterial artificial chromosomes

o Yeast artificial chromosomes

o Shuttle vectors a vector (usually a plasmid) constructed sothat it can propagate in two different host species



Plasmid from E.coli

Viral vectors (Phage)

Cosmid vector



Stem cellsy Stem cells special cells that have the ability to divide for an

indefinite period and can give rise to a wide variety of specializedcell types.

y Types of stem cells based on its ability to differentiate:

Totipotent stem cells differentiate to all kind of cells and ableto form new organism

Pluripotent stem cells differentiate to derivates of threeembryonal layer (ectoderm, mesoderm, endoderm)

Multipotent stem cells differentiate to one specific organ ortissue

Unipotent stem cells can·t differentiate to specific tissues, buthave fast regeneration and proliferation abilities



y In human, there are two types of stem cells:

1. Embryonic stem cells2. Adult stem cells



8. Students Able to Explain DNA Testy What make we look different one another?

y Junk DNA loci of STRs (Short Tandem Repeats)

y STRs are sections of DNA arranged in back-to-back repetition (a

ysimple sequence is repeated several times in a row).

y Example of STRs:

y TCAT TCAT TCAT TCAT TCAT TCAT

y The number of repeats found in pairs of STRs varies from one

person to another. STR DNA fingerprint of a person is completelydifferent one another. The probability of anyone else havingidentical alleles with a person at each and every one of his or herloci is outrageously small.



General Process of DNA TEST

Genetic Analysis

Extracting DNA

Collecting Biological Samples



y Common samples for DNA tests:

Saliva

Buccal swabs

Semen Blood

Hair

Collecting BIOlogical samples



DNA Extractions

y General methods:

1. Break open the sample cells to free the DNA from the

nucleus (cell lysis).

2. Remove the proteins (which make up most of the biologicalsample) by digesting them with an enzyme.

3. Remove the DNA from the solution by adding alcohol.



ANALY SIS

y Using PCR (Polynucleotide Chain Reactions) copies of

specific fragments of DNA molecules

y

Why we need copies of DNA? Current technology used in DNA fingerprinting can·t detect

the DNA unless large amounts are present.

Matches must be exact when it comes to DNA

fingerprinting and forensic genetics. To avoidmisidentifications, many STR loci from each sample must be

examined.



PCR Methods



y Next step:

y Read DNA fingerprint using electrophoresis

DNA molecules is negatively

cha

rged. So, elect

rophoresisseparate the DNA fragments

based on its lengths and

sizes.

Introductory to Molecullar Biology

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