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The Central Dogma of Molecular Biology

In  the  Central  Dogma  of  Molecular  Biology,  this  process  occurs  when  mRNA  is  made  from  DNA?  

A.  TranscripBon    B.  TranslaBon    C.  ReplicaBon    

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DNA: The ultimate instruction manual

•  3,080,000,000 characters (750 MB data or 5000 textbooks) –  Only 4 letters make up the code

•  Human possess approx. 29,000 protein-coding genes on 23 chromosomes –  Approximately 1000 genes per

chromosome

•  All of this information is in each and every one of our 60-90 trillion

hDp://askabiologist.asu.edu/explore/dna-­‐abcs  

Watson and Crick

•  Wrote the 1953 Nature Journal article describing the structure of DNA –  Molecular Structure of Nucleic Acids: A Structure of Deoxyribose Nucleic

Acid –  Won the 1962 Nobel Peace Prize in Physiology or Medicine

•  Demonstrated the double helix structure of DNA –  Used X-ray distraction data that was collected by Rosalind Franklin –  http://www.youtube.com/watch?v=35FwmiPE9tI

James  D.  Watson   Francis  Crick  

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The structure of deoxyribonucleic acid (DNA)

Nucleus  

hDp://campus.udayton.edu/~hume/DNA/DNA.htm  

www.wikipedia.org  

Sugar  phosphate  backbone    Base  (nucleoBde)    Hydrogen  bond  

What  is  the  direcBonality  of  DNA?  

A.  5’  to  3’  B.  3’  to  5’  C.  4’  to  2’  

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The double helix

www.wikipedia.org  Adapted  from  www.genome.gov  

Phosphodiester Bond

Adapted  from:  hDp://www.web-­‐books.com/MoBio/Free/Ch3A5.htm  

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In  double  stranded  DNA,  adenine  pairs  with  which  nucleoBde?  

A.  Adenine    B.  Thymine    C.  Cytosine    D.  Guanine    

How  many  hydrogen  bonds  form  between  guanine  and  cytosine  nucleoBdes  in  double  stranded  DNA?  

A.  1  B.  2  C.  3  D.  4  

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A  phosphodiester  bond  forms  between…  

A.  5’  PO4  and  2’  OH  B.  5’  PO4  and  3’  OH  C.  5’  OH  and  2’  PO4    

D.  5’  OH  and  3’  PO4  

DNA is not a mysterious, complex molecule from a textbook!

     

hDp://learn.geneBcs.utah.edu/content/begin/tour/  

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DNA: Prokaryotes vs. Eukaryotes Prokaryotes

ATG TAA TAG TGA

DNA Term.

promoter

ATG TAA TAG TGA

DNA Term.

Eukaryotes promoter

Operon A cluster of genes that are controlled by a single

promoter. •  Found in prokaryotes and some eukaryotes

(nematodes and flies) •  Genes are transcribed together into a single

mRNA –  Transcription is regulated by the operator sequence,

which is between the promoter and genes •  Translation occurs by:

–  Translating mRNAs together –  Separating the mRNAs into single mRNAs, which are

then translated.

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The lac Operon The genes in the lac Operon are involved in the

breakdown and metabolism of lactose

Modified from: http://en.wikipedia.org/wiki/Lac_operon

https://www.youtube.com/watch?v=oBwtxdI1zvk

DNA Replication

http://www.youtube.com/watch?v=hfZ8o9D1tus

hDp://universe-­‐review.ca/F11-­‐monocell.htm  

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Bacterial  DNA  contains  introns  

A.  True  B.  False  

What  is  the  purpose  of  helicase  in  DNA  replicaBon?  

A.  Unwinds  the  dsDNA  into  single  strands  

B.  Adds  a  short  single  stranded  oligo  to  iniBate  DNA  synthesis    

C.  Forms  phosphodiester  bonds    

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Let’s make Candy DNA! You each are going to receive a kit with materials needed to make DNA. Inside your kit you will find: •  Licorice – which will serve as your

phosphodiester bonds •  Jelly candy – which will serve as your

nucleotides •  Tooth picks – which will serve as your

hydrogen bonds. You will also attach your nucleotides to your phosphodiester bonds with toothpicks.

Each student will need to make a double stranded DNA molecule based on the single stranded sequence (sense strand) that is in your kit. Be sure to include the correct anti-sense strand as well as the appropriate number of hydrogen bonds.

A          T        C          G  nucleo

Bdes  

H  -­‐  b

onds  

Phosphodiester  backbone  

Ribonucleic Acid (RNA)

Adapted  from  www.genome.gov  

ribose  

deoxyribose  

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What are some differences between DNA and RNA?

In  mRNA,  adenine  pairs  with  which  nucleoBde?  

A.  Adenine    B.  Thymine    C.  Uracil    D.  Cytosine    E.  Guanine    

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mRNA  is  single  stranded.  

A.  True  B.  False  

Transcription = the process of making RNA from DNA

DNA   RNA   PROTEIN  TRANSCRIPTION

     TRANSLATION

     

REPLICATION  

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Definitions •  Promoter: a region of DNA that is upstream of a gene

where RNA polymerase binds and initiates transcription.

•  Transcription factor: a protein that binds DNA at specific sequences and aids in the initiation of transcription.

•  RNA polymerase: an enzyme involved in transcription that synthesizes an mRNA molecule from a DNA template

•  Terminator: a region of DNA that is downstream of a gene where RNA polymerase stops transcribing a gene.

Simplified overview of transcription

www.blackwellpublishing.com  

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Transcription Video https://www.youtube.com/watch?v=WsofH466lqk

What  is  a  promoter?  

A.  A  protein  that  acBvates  RNA  polymerase  

B.  A  single  stranded  oligo  that  tells  RNA  polymerase  where  to  transcribe  mRNA  

C.  An  area  of  DNA  upstream  of  the  gene  where  RNA  polymerase  binds  

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Transcription: Prokaryotes vs. Eukaryotes

transcription

ATG TAA TAG TGA

RBS

DNA

mRNA

Term. Gene promoter

Prokaryote

transcription

ATG TAA TAG TGA

RBS

DNA

mRNA

Term. Gene

RBS mRNA

processing

Eukaryotes promoter

Which  of  the  following  is  not  a  funcBon  of  the  5’  cap  of  eukaryoBc  mRNA?  

A.  Transport  of  mRNA  out  of  the  nucleus  

B.  IniBaBon  of  transcripBon  

C.  Increase  the  stability  of  mRNA  

D.  Aid  in  mRNA  splicing  

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Translation Process by which the mRNA is decoded by the ribosome to

generate a specific polypeptide made up of amino acids

hDp://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%20101%20lectures/protein%20synthesis/protein.htm  

Translation    hDp://www.youtube.com/watch?v=5bLEDd-­‐PSTQ&feature=related  

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Genetic Code

hDp://www.biology.iupui.edu/biocourses/N100/2k3ch13dogma.html  

Translation: Prokaryotes vs. Eukaryotes

transcription

Prokaryotes

ATG TAA TAG TGA

translation

RBS

DNA

mRNA

protein

Term. Gene

transcription

ATG TAA TAG TGA

translation

RBS

DNA

mRNA

protein

Term. Gene

RBS mRNA

processing

promoter promoter Eukaryotes