SBI4U – Molecular Genetics
106751974
Date: ___________________________
Transcription and Translation
Transcription involves the synthesis of ________ under the direction of ________
The information is simply transcribed or __________ from one molecule to the other
The ________ molecule acts as a template for the assembly of ___________
The RNA molecule produced functions as a _________________________ from
DNA to the polypeptide synthesizing machinery of the cell and is therefore called
________________________________
The actual synthesis of a polypeptides (_________________) under the direction of
___________ is called translation
There is a change in language with the cell translating the ____________________
sequence of mRNA into the ____________________ sequence of the polypeptide
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SBI4U – Molecular Genetics
106751974
Transcription: The Details
The enzyme responsible for transcription is
______________________________
Transcription occurs in three stages:
1. ________________________
2. ________________________
3. ________________________
Initiation
RNA polymerase binds to regions of DNA called ________________________
The promoter region includes an _______________ Site where transcription begins
Proteins called _________________________ aid RNA polymerase in searching for
__________________ regions along the DNA molecule
In eukaryotic cells, RNA polymerase recognizes a region called the
________________ (region rich in ______________ and _____________) to initiate
transcription
Once RNA polymerase binds to the promoter region it separates the DNA strands at
the initiation site
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SBI4U – Molecular Genetics
106751974
Elongation
__________________________ moves along the DNA, unwinding it and separating
the strands
Enzymes add nucleotides to the _____ end of the growing mRNA molecule
Goes from ____ end to the ____ end
Termination
Transcription proceeds until RNA polymerase reaches a ______________________
on the DNA
mRNA molecule _________ away from the DNA ____________ and the non-coding
strand reforms its __________________ shape
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SBI4U – Molecular Genetics
106751974
The ends of the mRNA molecule are also modified with a ________________ and a
__________________ added to inhibit _________________ of the mRNA molecule
Translation: The Details
Interpreting a genetic message encoded in mRNA requires another type of RNA
molecule called ____________________________
tRNA functions to __________________ amino acids from the cytoplasm to a
ribosome
Each tRNA associates with a particular mRNA ______________ and a particular
________________________
A codon is a sequence of _________________________
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SBI4U – Molecular Genetics
106751974
tRNA Structure
tRNA is like a “_______________” with a
"nucleic acid word" (________________) on
one side and a "protein word"
(___________________) on the other side
Specific amino acids are added to each
tRNA molecule with a specific enzyme
called ___________________________
_____________________
The active site binds an amino acid and
ATP to the tRNA
Once ATP is bound it releases two
phosphate molecules that drives the joining
of the ____________________ to
__________________
Translation occurs in three stages:
1. ________________________
2. ________________________
3. ________________________
Chain Initiation
Initiation begins with two subunits of ribosomes, a mRNA molecule and the initiator
tRNA
anticodon: __________
amino acid:
_____________________
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SBI4U – Molecular Genetics
106751974
Ribosome Anatomy
A functional ribosome consists of two subunits
a ___________ (________________) subunit
a ___________ (________________) subunit
It has a mRNA binding site and three tRNA binding sites known as the ___________
_________ sites
The A site holds the tRNA carrying the next amino acid to be ________________ to
the polypeptide chain
The P site holds the tRNA attached to the ____________________________
The ___________________ tRNA leaves via the E site (___________)
Elongation
Amino acids are added one by one to the initial amino acid
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SBI4U – Molecular Genetics
106751974
Termination
Elongation continues until a _________________________ codon is reached
Possible termination codons include:
__________________________________
All these signal a “__________________” in translation
Proteins called ________________________ cause the _________________ of
completed polypeptide from tRNA in the P site
Ribosomes separate into its subunits and are _________________ for further use
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