Ken Tao is the MedSchoolCoach expert on MCAT, and will discuss Stop Codons:
UAA, UGA and UAG.
U Are Annoying, U Go Away, U Are Gone.
Hey everyone. Welcome to our first ever MCAT Mnemonic Monday. My name is Ken and I’m an MCAT expert with MedSchoolCoach. Today, we have a MCAT biology mnemonic for you and it’s on stop codons.
As you recall, during translation, ribosomes read the genetic code on mRNA to determine which amino acids to add to the growing polypeptide chain. The ribosomes read the nucleotides in sets of three called “codons.”
Since there are four possible nucleotides in mRNA, that means that there are sixty-four possible codons. Of the sixty-four possible codons, there are three stop codons. The stop codons do not encode for an amino acid. Instead, tell the ribosome that the protein is finished.
The three stop codons are U A A, U G A and U A G.
The mnemonic here is to think of an annoying person. When an annoying person comes up to you, you’re gonna tell them: Stop, U Are Annoying, U Go Away, and U Are Gone.
So that’s the mnemonic for the three stop codons.