Central dogma

The Core

The Core for

Heredity

Heritable traitsare governed by geneswhich are passed fromone generation to the next

12.3 - 12.5, 13.1 - 13.2

11.3 - 11.5, 12.1 - 12.2

The Core for the

CentralDogma

Biological information flowsfrom DNA to RNA to proteins.

A way to think aboutthis flow of information

DNA RNAà Proteinà

Bread Pudding

2 cups whole milk (or 2 cups half & half)1/4 cup butter2/3 cup brown sugar (light or dark, depending on taste preference)3 eggs2 teaspoons cinnamon1/4 teaspoon ground nutmeg1 teaspoon vanilla extract3 cups bread, torn into small pieces (french bread works best)1/2 cup raisins (optional)

1. In medium saucepan, over medium heat, heat milk (or half & half) just until film forms over top. Combine butter and milk, stirring until butter is melted. Cool to lukewarm.

2. Combine sugar, eggs, cinnamon, nutmeg, and vanilla. Beat with an electric mixer at medium speed for 1 minute. Slowly add milk mixture.

3. Place bread in a lightly greased 1 1/2 quart casserole.

4. Sprinkle with raisins if desired. Pour batter on top of bread.

5. Bake at 350 degrees F for 45 to 50 minutes or until set. Serve warm.

Making Stuff from Instructions

InstructionsTemplate

PrintedInstructionsà Final

Product à

Making Stuff from Instructions

InstructionsTemplate

PrintedInstructionsà Final

Product à

DNA RNAà Proteinà

DNA

RNAand

Base Pairing

TranscriptionMaking messenger RNA (mRNA) from DNA

Transcription

• TGGCAACTGATGCCAGCTCGGTCAA • •

• ACCGTTGACTACGGTCGAGCCAGTT • •• TGGCAACTGATGCCAGCTCGGTCAA • •

à• ACCGTTGACTACGGTCGAGCCAGTT • •à• UGGCAACU

• UGGCAACUGAUGCCAGCUCGGUCAA • •

Transcription

• TGGCAACTGATGCCAGCTCGGTCAA • •• UGGCAACU


à


• ACCGTTGACTACGGTCGAGCCAGTT • •à

Transcription



à



mRNA

Transcription



à



template strand

How do we go from sequences of nucleotides to sequences of amino acids?

There are four kinds of nucleotides in mRNA

There are twenty kinds of amino acids in proteins

CodonsTri-nucleotide sequences that code for an amino acid

http://evolution-textbook.org/content/free/figures/02_EVOW_Art/26_EVOW_CH02.jpg

Reading Frame[A] way of breaking a sequence of nucleotides in DNA or RNA into three letter codons which can be translated in amino acids.

There are 3 possible reading frames in an mRNA strand: each reading frame corresponding to starting at a different alignment.

http://en.wikipedia.org/wiki/Reading_frame


UGGCAACUGAUGCCAGCUCGGUCAA• • •



[ [ [ [ [ [ [ [

[ [ [ [ [ [ [ [

[ [ [ [ [ [ [ [

Reading Frame

Reading Frame

UGGCAACUGAUGCCAGCUCGGUCAA• • •[ [ [ [ [

TranslationMaking proteins from mRNA

UGGCAACUGAUGCCAGCUCGGUCAA• • •[ [ [ [ [

Met Pro Ala Arg Ser • • •

Translation

UGGCAACUGAUGCCAGCUCGGUCAA• • •[ [ [ [ [Met Pro Ala Arg Ser • • •



à• UGGCAACUGAUGCCAGCUCGGUCAA • •


Now let’s look at the physical processes ofthe Central Dogma

Reverse Transcriptase

Proteins are synthesizedfrom mRNAby the ribosome

Reverse Transcriptase

The Ribosome

tRNA secondarystructure

tRNA tertiary

structure

tRNA in a simplified depiction

Translation in a simplified depiction

DNAReplication

DNA is replicated semi-conservatively by DNA polymerase

Figure 6-6 Essential Cell Biology (© Garland Science 2010)

Base Pairingis at the heartof DNA replication

The Central Dogma and Genetic Codeare Universal

Class ActivityDNA: 7 people

RNA polymerase: 1 person

mRNA: 7 people

tRNA: 3 people

Ribosome: 1 person

Amino Acids: 3 people

Mutations…changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus.

Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication.

http://en.wikipedia.org/wiki/Mutation

Some Mutationsare like copying errors.are like copying errors.are like copying errors.are like copying errors.are like capying errors.are like capying errers.are like capying errers.are like capying errers.

Data Corruption

Kinds of MutationsSubstatutionexchange of a single nucleotide fur another

Insaertionaddition of one or moare extra nucleotides

Dletionremoval of one or mre nucleotides

Kinds of MutationsAmplificationAmplificationmultiple copies of all chromosomal regions, increasing the dosage of the genes located within them

noisrevnIportions of DNA get flipped around

Point Mutationsare like typos.

Point MutationsSubstatutionexchange of a single fur another

Insaertionaddition of one extra nucleotides

Dletionremoval of one nucleotides

Silentdoesn’t change the amino acidthe original codon coded for

Miscensechanges the amino acid she original codon coded for

Non.senseresults in a stop. codonthat prematurely ends translation

Frameshift Mutation

[A] genetic mutation caused by insertions or deletions of a number of nucleotides that is not evenly divisible by three from a DNA sequence. Due to the triplet nature of gene expression by codons, the insertion or deletion can change the reading frame (the grouping of the codons), resulting in a completely different translation from the original.

http://en.wikipedia.org/wiki/Frameshift_mutation

A genetic mutation caused by insertions or deletions of a number of nucleotides that is not evenly divisible by three from a DNA sequence.

e neticmu tationca usedby insertionsor deletionsof anu mberof nucleotidesth atis notev enlydi visibleby threefr oma DNAse quence.

0101011100010011010001101

1100100110001010001011011

1001000101000110100111001

0101001101010101010101110

0010011010001101110010011

0001010001011011100101001

0101100110100100110010101

0011011100010011010100110

1110010011000101000101101

1100100011101010001101001

110010101001101…

0101011100010011010001101

1100100110001010001011011

1001000101000110100111001

0101001101010101010101100

0100110100011011100100110

0010100010110111001010010

1011001101001001100101010

0110111000100110101001101

1100100110001010001011011

1001000111010100011010011

10010101001101…

• • •GCAACUGAUGCCAGCUCGGUCAAUAG

• • •GCAACUGAUGCCAGUCGGUCAAUAGC

What kind of mutation is this?


• • •GCAACUGAUGCCAGUCGGUCAAUAGC


[ [ [ [ [

Met Pro Ala Arg Ser Ile

[

[ [ [ [ [

Met Pro Val Gly Pro stop

[


• • •GCAACUGAUGCCGGCUCGGUCAAUAG



• • •GCAACUGAUGCCGGCUCGGUCAAUAG


[ [ [ [ [


[

[ [ [ [ [


[


• • •GCAACUGAUGCCAACUCGGUCAAUAG



• • •GCAACUGAUGCCAACUCGGUCAAUAG


[ [ [ [ [

Met Pro Thr Arg Ser Ile

[

[ [ [ [ [


[

Bread Pudding

2 cups whole milk (or 2 cups half & half)

1/4 cup butter

2/3 cup brown sugar (light or dark, depending on taste preference)

3 eggs

2 teaspoons cinnamon

1/4 teaspoon ground nutmeg

1 teaspoon orange extract

3 cups bread, torn into small pieces (french bread works best)

1/2 cup raisins (optional)

1. In medium saucepan, over medium heat, heat milk (or half & half) just until film forms

over top. Combine butter and milk, stirring until butter is melted. Cool to lukewarm.

2. Combine sugar, eggs, cinnamon, nutmeg, and vanilla. Beat with an electric mixer at

medium speed for 1 minute. Slowly add milk mixture.

3. Place bread in a lightly greased 1 1/2 quart casserole.

4. Sprinkle with raisins if desired. Pour batter on top of bread.

5. Bake at 350 degrees F for 45 to 50 minutes or until set. Serve warm.

DNA Probesare like search terms.

Met Pro Ala Arg Ser Ala Cys • • •

Find the genefor this protein…

ATCGCAACTGATGCCAGCTCGGTCAATAGGCTGAACTGTTCAAGGCTCAGTCGAGTACT

AGGTCAGGCTTGCACTACTGCCGTCTATCG

• • •CCTACTGGGTGCCAAGGGTCATGATGA• • •TTGAAACTGGTGCCAAGGGTCATGAUG

in a long DNA sequence

Met Pro Ala Arg Ser • • •

http://evolution-textbook.org/content/free/figures/02_EVOW_Art/26_EVOW_CH02.jpg

AUGCCAGCACGAUCA • • •

[ [ [ [ [ Met Pro Ala Arg Ser • • •

CCUCCGCCC

GCUGCGGCC

CGUCGGCGCAGAAGG

ATCGCAACTGATGCCAGCTCGGTCAATAGGCTGAACTGTTCAAGGCTCAGTCGAGTACT



CCAGCTCGGT • • •

CCTGCACGAT • • •CCTGCTCGGT • • •

CCTGCCCGGT • • •

ATCGCAACTGATGCCAGCTCGGTCAATAG

GCTGAACTGTTCAAGGCTCAGTCGAGTACT



GGTCGAGCCAGTT • • •

DNA probes are usually 100 - 1000 nucleotides long

Central dogma

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