Transcript How does DNA work

How does DNA work?
Building the Proteins that
your body needs
DNA contains it all
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Deoxyribonucleic acid contains the
instructions for protein formation
DNA is a double helix with base pairs
complimenting each other.
Adenine and thymine/ Guanine and
Cytosine are base pairs
Each strand of DNA exposes the necessary
information to build two identical
strands of DNA
DNA Replication
Proteins
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Made of amino acids
There are only 20 amino acids that
in varied combination make up the
proteins we need.
Used for growth and repair of tissue
DNA contains the instructions for
producing protein
DNA genetic information is
transferred
DNA can not leave the nucleus
 RNA is made, using DNA as a blueprint
 Gene expression is the use of the
genetic information in DNA to make
protein
 DNA has the code
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Transcription and Translation
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Transcription is when a copy of
RNA is made by using the DNA
template
Translation is when three
different kinds of RNA work
together in order to assemble
amino acids into proteins
Transcription and Translation
How DNA makes RNA
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Inside the nucleus DNA makes
single strand copies of RNA to
be sent out into the cell
RNA is similar to DNA except
Thymine (T) is replaced with
Uracil(U)
Transcription
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A portion of the helix unwinds,
exposing a sequence of genetic
information
Enzyme RNA polymerase binds to
exposed bases, moving along the
strand, pairing complimentary bases
to build a strand of RNA
mRNA passes out of the nucleus and
into the cytoplasm of the cell
Transcription
RNA
Polymerase
mRNA
Breaking the Code - mRNA
Codon is a nucleotide triplet that
determines which amino acid will be used
for the appropriate protein.
 Every three base codon is instructions for
another amino acid.
 Genetic code is the correspondence
between nucleotide triplets and the
amino acids in proteins
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Reading the Code
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Using the genetic code chart, it is possible
to figure out the amino acid used for a
specific protein
On the left side of the chart, use the first
codon
The top of the chart refers to the second
codon and the third is on the side, line it
up and it tells you the amino acid
RNA makes protein
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mRNA binds to a site on a Ribosome
Ribosomes produce protein and use
mRNA has the instructions
tRNA (transfer RNA) carries amino acids
to the ribosomes
On one end of tRNA is a 3 nucleotide
sequence called a anticodon
Anticodons are complementary to
mRNA codons
Regulating Gene expression
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Protein production must be regulated or
we have unrestricted growth
Repressor proteins stop the process
Inducers begin the process
Proteins are even needed for this.