Name ____________________________________ Date ____________ Period _____

PROTEIN SYNTHESIS: TRANSLATIONRaven 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?

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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 __________

organelle or enzyme?

Structure

ribosomal RNA (________) & __________________

2 subunits

large

small

____ site (aminoacyl-tRNA site)

holds tRNA carrying next amino acid to be added to chain

____ site (peptidyl-tRNA site)

holds tRNA carrying growing polypeptide chain

____ site (exit site)

empty tRNA leaves ribosome from exit site

Building a polypeptide

________________

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brings together mRNA, ribosome subunits, initiator tRNA

________________

adding amino acids based on codon sequence

________________

end codon

Protein targeting

Signal peptide

address label

Protein Synthesis in Prokaryotes

Prokaryote vs. Eukaryote genes

Prokaryotes Eukaroyotes

_________________ _________________

_________________ _________________

_________________ _________________

_________________ _________________

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Destinations:o secretiono nucleuso mitochondriao chloroplastso cell membraneo cytoplasmo 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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