Here are six events of protein synthesis, in a mixed order…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Here are six events of protein synthesis, in a mixed order.
(1) A release factor binds to the stop codon.
(2) A charged tRNA enters the empty site of the ribosome.
(3) The small subunit of the ribosome binds the mRNA.
(4) The initiator tRNA binds to AUG.
(5) A peptide bond is made, and the ribosome moves one codon.
(6) ATP activates an amino acid, and it is joined to its tRNA.
Put them in the right order, and name the stage of each: charging, initiation, elongation or termination.
Need a reminder? The key ideaShow
A tRNA has an anticodon at one end and an amino acid acceptor end at the other. The ribosome reads the mRNA from 5′ to 3′, from AUG to a stop codon. A stop codon has no amino acid, so a coding region of nucleotides makes amino acids, of about 110 Da each.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The tRNAs must be charged first: (6), charging.
Step 2. Then the ribosome starts: (3) and (4), initiation.
Step 3. Then the polypeptide grows: (2) and (5), elongation. These two repeat for every codon.
Step 4. At the stop codon: (1), termination.
Answer: 6, 3, 4, 2, 5, 1.
Check. Charging comes before the translation, and the release of the polypeptide is the last step.
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