RNA and Protein Synthesis Notes

Define Gene –

What does a gene ultimately code for? _____________________________________

RNA review
o 3 main differences compared to DNA
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________________________________________________

_________________________________________________

_________________________________________________
o 3 types of RNA

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____________________
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____________________

____________________
Protein Synthesis
o Occurs in two main steps:

______________________________________

______________________________________
o Transcription occurs in the _____________________________________
o Translation occurs in the _______________________________________

Transcription
o Occurs in 3 main steps:
o Initiation –

The enzyme ___________________________________ recognizes a
specific sequence of DNA called a __________________________
region.

Promotors –

RNA polymerase separates the DNA strands by breaking the
_______________ bonds.
o Elongation –

RNA polymerase uses the DNA strand as a ______________________
and pairs free-floating RNA nucleotides together to form the
backbone of the _________________________ strand.
o Termination –

mRNA strand is continuously built until RNA polymerase reaches a
specific sequence of DNA known as the
__________________________________ sequence.


Then, mRNA separates from the DNA and transcription is complete.
Transcription vs. Replication
o Transcription results in :
o Replication results in:

The Genetic Code
o What is the overall purpose of the genetic code in DNA?
__________________________________________

Proteins
o Long chains of _________________ ____________________ that are
joined together by ___________________________ bonds.
o There are _______________ different amino acids.
o The _________________________ and ___________________________ of
proteins are determined by the sequence of amino acids.

Codon
o The genetic code is read in groups of __________ letters at a time
o ____________ codons are possible


Codons either code for an amino acid or they give instructions.
Translation
o Takes place on __________________, either in the cytoplasm or attached to
the E.R.
o The ribosome will _____________________ the message on the mRNA
strand to produce a protein (polypeptide).
o Occurs in 3 main steps:
o Initiation:

mRNA leaves the nucleus and travels through the cytoplasm to the
ribosome. mRNA attaches to the ribosome.

_______________= the start codon = codes for __________________

tRNA anticodon will temporarily bind to the complementary codon on
the mRNA molecule
o Elongation:

The ribosome has two __________________ sites, allowing two tRNA
molecules to line up side by side.

The ribosome forms a __________________ __________________
between the first and second amino acids on the tRNA molecules.

At the same time, the ribosome ___________________ the bond that
held the first tRNA molecule to its amino acid and releases the tRNA
from the ribsome.

The __________________ floats away, allowing the ribosome to
move down the mRNA molecule and bind another tRNA.

The ribosome continues to move along the __________________,
attaching new tRNA molecules and adding more
_______________________ _______________________ to the
__________________________________________ chain.
o Termination:

This process continues until the ribosome reaches one of the three
possible __________________ codons on the mRNA.

Then, the ____________________________ detaches from the
mRNA.

The result is a ______________________ that then travels to the
_____________________ apparatus to be modified for use in the cell.