Transcript 71071_Protein_synthesis

DNA -> RNA ->
Proteins
The basic language of all living
things.
A Gene
• A gene is a section
of DNA that codes
for a specific protein
• Only a very small
percentage of our
DNA (perhaps 1%)
actually does this
RNA - ribonucleic acid
•
•
•
•
RNA is short compared to DNA
RNA has one strand instead of two
C, G, A, and U (uracil) instead of C,G,A, and T
(U takes the place of T)
Messenger RNA
• DNA is a large
and bulky
molecules, it
does not travel
well, so when it
wants to make
a protein it
makes and
mRNA copy of
the instructions
Transcription
• This process is called transcription,
because the DNA transcribes “copies”
itself
• It takes advantage of base pairing
RNA Polymerase
• An enzyme
called RNA
Polymerase
makes all of this
happen
• The enzyme
puts the new
nucleotides in
place
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mRNA finds a ribosome
• mRNA moves out of
the nucleus into the
cytoplasm of the
cell where it finds a
ribosome
• The ribosome is
made of RNA and it
will serve as a work
bench for making
proteins
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Translation
• Once attached to
the ribosome, the
mRNA is translated
from the language
of nucleic acids to
the language of
amino acids
• Each three letter
word or “codon”
calls for one amino
acids
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tRNA
• It is the job of the
transfer RNA is to
transfer the
correct amino
acid to the
correct mRNA
codon
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Polypeptide chain
• In this way a
polypeptide is
made
• Each time a a
tRNA connects to
a mRNA one
amino acid is
added to the
growing chain
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Summary
• Can you label
all of the parts
in this
diagram?
DNA
• A_________
• B_________
mRNA
Amino Acid
• C_________
tRNA
• D_________
Ribosome
• E_________
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