Back to: MICROBIOLOGY 200 LEVEL
Welcome to class!
Hello, my ever-curious genius! It’s so great to have you here again. You’ve been doing an amazing job so far — and today, we’re going to learn something truly fascinating and practical: Codons and tRNAs. These are some of the key players that make sure the right proteins are made in your body, just like how a chef follows a recipe to cook a delicious meal. Let’s make this topic as sweet and easy as suya on a Friday night!
Codons And tRNAs
Have you ever followed a recipe to cook something nice, like moi moi or jollof rice? The ingredients must be added in a particular order, using exact measurements. If you mix it up, you could spoil the whole meal.
That’s exactly how codons and tRNAs work in your cells. They help make sure the correct amino acids — the building blocks of proteins — are added in the right order, just like ingredients in a recipe. Your body is full of tiny chefs (ribosomes) that read the instructions (mRNA codons) and use helpers (tRNAs) to build proteins perfectly!
What Are Codons?
A codon is a group of three nucleotides on the mRNA that codes for a specific amino acid.
Think of a codon as a “word” in the genetic language.
There are 64 possible codons, but only 20 amino acids, so some amino acids are coded by more than one codon.
There are also special codons:
Start codon: AUG (it tells the ribosome where to start building the protein — it also codes for the amino acid methionine).
Stop codons: UAA, UAG, and UGA (they signal the end of the protein chain — like saying “done!” in a recipe).
What Are tRNAs?
tRNA stands for transfer RNA.
tRNA is like a delivery person. It brings the correct amino acid to the ribosome, using an anticodon to match the codon on the mRNA.
Each tRNA has:
A specific amino acid it carries.
An anticodon, which is a set of three bases that pairs with the matching codon on the mRNA.
tRNAs make sure that amino acids are placed in the right order to form the correct protein.
Let’s say you’re building a Lego car. The mRNA codon is the instruction manual — it tells you which Lego piece comes next. The tRNA is like a friend handing you the right piece as you build, based on the instructions. If you get the wrong piece (wrong amino acid), the whole car (protein) might not work properly.
So, codons provide the recipe, and tRNAs follow that recipe to deliver the correct materials.
Summary
- Codons are groups of three bases on mRNA that code for specific amino acids.
- There are 64 codons, including start (AUG) and stop codons (UAA, UAG, UGA).
- tRNA carries amino acids to the ribosome and matches them to the mRNA codon using its anticodon.
- Each tRNA is specific to one amino acid.
- Codons and tRNAs work together to ensure proteins are built correctly and efficiently.
Evaluation
- What is a codon, and how many bases does it contain?
- What does the start codon AUG code for?
- Name the three stop codons.
- What is the function of tRNA?
- Explain how tRNA matches with mRNA during protein synthesis.
Give yourself a big high five — you’ve just understood one of the most beautiful and precise parts of biology! Codons and tRNAs may be tiny, but they do mighty work in keeping your body healthy and strong. With Afrilearn, you’re not just learning — you’re building a powerful future. Keep going, and I can’t wait to learn with you in the next exciting lesson!