Name ____________________________________ Date ____________ Period _____
PROTEIN SYNTHESIS: TRANSLATION
Raven Ch. 15
Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to
life processes.
Essential Knowledge:
 Heritable information provides for continuity of life.
 Expression of genetic information involves cellular and molecular mechanisms.
 The processing of genetic information is imperfect and is a source of genetic variation.
 Cells communicate by generating, transmitting and receiving chemical signals.
 Transmission of information results in changes within and between biological systems.
Translation-- from _________________ language to __________________ language
Cracking the code

Crick

determined _____________________________ system
WHYDIDTHEREDBATEATTHEFATRAT

Nirenberg (47) & Khorana (17)

determined mRNA–amino acid match

added fabricated mRNA to test tube of ribosomes, tRNA & amino acids

created artificial UUUUU… mRNA

found that UUU coded for phenylalanine
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
Code for ALL life!




strongest support for a _____________________ for all life
Code is ___________________________

several codons for each amino acid

3rd base “____________________”
Start codon

___________________

___________________
_________________ codons

UGA, UAA, UAG
How are the codons matched to amino acids?
2
Transfer RNA structure ( __________________)

“Clover leaf” structure
o _____________________ on “clover leaf” end
o ___________________ attached on 3 end
Loading tRNA

Aminoacyl tRNA synthetase

enzyme which bonds _____________ to _____________

bond requires energy

ATP  AMP

bond is unstable

so it can release amino acid at ribosome easily
______________________

Facilitate coupling of tRNA _____________ to mRNA __________



Structure

ribosomal RNA (________) & __________________

2 subunits
large

small
holds tRNA carrying next amino acid to be added to chain
____ site (peptidyl-tRNA site)



____ site (aminoacyl-tRNA site)


organelle or enzyme?
holds tRNA carrying growing polypeptide chain
____ site (exit site)

empty tRNA leaves ribosome from exit site
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Building a polypeptide

________________


________________


brings together mRNA, ribosome subunits, initiator tRNA
adding amino acids based on codon sequence
________________

Destinations:
o
o
o
o
o
o
o
end codon
Protein targeting

Signal peptide

address label
Protein Synthesis in Prokaryotes
Prokaryote vs. Eukaryote genes
Prokaryotes
Eukaroyotes
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
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secretion
nucleus
mitochondria
chloroplasts
cell membrane
cytoplasm
etc…
Translation in Prokaryotes

Transcription & translation are ___________________in bacteria

DNA is in _________________

no mRNA _________________

ribosomes read mRNA ______________________
Translation: prokaryotes vs. eukaryotes

Differences between prokaryotes & eukaryotes

__________________ separation between processes

takes eukaryote ~1 hour
from DNA to protein

no RNA processing
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