8-5 Translation
(In the ___________________)
The mRNA made during transcription is used to make a protein
mRNA _________________
_____________________________ are coded by mRNA base sequences.
______________________________ converts mRNA messages into polypeptides.
A ____________________is a sequence of _____________ nucleotides that codes for an amino acid.
Proteins
Remember that proteins, which are sometimes called polypeptides,
are macromolecules made of monomers called amino acids.
During translation, ribosomes decode the ___________________message
(made of nucleotides) to make polypeptide chains (made of amino acids).
Step 1: Two subunits of the ribosome attach to
the ________________________.
Step 2: __________________________ read the
mRNA ______________’  _____________. As
each codon of the mRNA moves through the
ribosome, the correct amino acid is brought to the
ribosome by ______________________.
The Genetic Code
In RNA, the nucleotides are read in “words” made of 3 nucleotide “letters”. Each “word” is
called a ______________________ and contains the genetic code for one
_____________________.
The first “word” or start codon is always the same for every protein. It is always
_____________.
What amino acid is associated with the codon AUG? ____________________
There are a total of ________different amino acids that can be arranged in different ways to make different proteins.
Step 3
Each___________________ molecule has a group of __________________
called the _______________________. These three nucleotides pair with the
codon. The tRNA molecule also has an ________________________ attached.
Step 4: _______________________ bonds form between amino acids to form the
_______________________ chain in a process called elongation (it makes the
longer.)
nucleotides
nucleotides in the
polypeptide chain
Step 5: The ribosome continues to match the _____________________ in the mRNA with ________________ in tRNA
until it reads a codon in the mRNA that says “stop.” A tRNA for “stop” does not carry an amino acid. No peptide bond
will form, so the ribosome releases the mRNA and the protein.
Step 6: The newly formed polypeptide will start to coil and bend, forming
the 3-D shape of proteins (recall the 4 levels of protein structure)
Why are proteins important?
Each protein has a specific function within living cells. Some functions of
proteins are:
acting as enzymes, to speed up and regulate chemical reactions.
making pigments
determining your blood type.
regulating cell growth and development.