🎓 Summary in Simple Words:

• Proteins are very important molecules in all living things.
• They are made by joining together small units called amino acids.
• Each amino acid has 4 parts (NH₂, COOH, H, and R group).
• Different R groups make amino acids different from each other.
• Your body uses about 20 types of amino acids to make many different proteins.

📚 Mnemonics Recap:

1. To remember the four groups in amino acids:

“A C H R” = A Cat Has Rabbits

• A = Amino group
• C = Carboxyl group
• H = Hydrogen
• R = Side group

🚪 Real-Life Analogy Recap:

• Protein = Train, Amino acids = Train cars
• Amino acids = Letters, Proteins = Sentences
• R group = Accessory that gives each amino acid its personality