Okay kiddo, so let's talk about start codon. Start codon is like the magic word or signal that tells our cells when to start making a protein.
Just like how we need to follow a recipe to make a cake, our cells need to follow a recipe to make a protein. And the start codon is the first word in that recipe.
The start codon is made up of three letters - A, U, and G when we read it in the language of our cells. And when the reading machine, called the ribosome, sees this magic word, it starts reading the recipe to make the protein.
So without the start codon, our cells wouldn't know when to start making the protein, and it would be like trying to bake a cake without knowing when to turn on the oven!