How does DNA work?

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How does DNA work?
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The Central Dogma
DNA



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The Central Dogma
DNA
RNA


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The Central Dogma
DNA
RNA
proteins

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The Central Dogma
DNA
RNA
proteins
you
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RNA

• Five differences between RNA and DNA
• Sugar in RNA is ribose instead of deoxyribose
• RNA is single stranded
• RNA contains Uracil instead of Thymine
• RNA is disposable
• RNA can be outside the nucleus, DNA cant
• If you are going from DNA to RNA what
  nitrogenous base would pair with Adenine?
• DNA C A G T T A
• RNA _ _ _ _ _ _

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ANSWER

• DNA C A G T T A
• RNA G U C A A U

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Types of RNA

• Key players in Protein Synthesis -
• Messenger RNA (mRNA) carry instruction copies
• Ribosomal RNA (rRNA) makes up ribosome along
  with proteins
• Transfer RNA (tRNA) brings amino acids to the
  ribosome

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Big picture of protein synthesis
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Transcription
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Translation
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Just Like Construction

• DNA is the master plan
• mRNA is the everyday blueprint
• rRNA is the builder
• tRNA is the gopher
• Amino Acids are the wood
• Proteins are the building

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Translation of the Genetic Code - Protein
Synthesis
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This is a molecule of messenger RNA. mRNA is
transcribed in the nucleus.
codon
mRNA molecule
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A ribosome attaches to the mRNA molecule.
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A transfer RNA molecule arrives.
It brings a specific amino acid to the first
three bases (codon) on the mRNA.
The three unpaired bases (anticodon) on the tRNA
link up with the codon.
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Another tRNA molecule comes into place, bringing
a second amino acid.
Its anticodon links up with the second codon on
the mRNA.
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A peptide bond forms between the two amino acids.
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The first tRNA molecule releases its amino acid
and moves off into the cytoplasm.
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The ribosome moves along the mRNA to the next
codon.
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Another tRNA molecule brings the next amino acid
into place.
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A peptide bond joins the second and third amino
acids to form a polypeptide chain.
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The process continues.
The polypeptide chain gets longer.
This continues until a termination (stop) codon
is reached.
The polypeptide is then complete.
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CODON TABLE
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1. What amino acids would be coded by the
following DNA sequence? CGGACCGCTATC 2. What
would be the DNA sequence for a polypeptide chain
(protein) that had the following amino
acids? Lysine-Cysteine-Proline