🚀 Main Idea: Gene mutations change protein structure, sometimes leading to serious health issues.

• A gene mutation is a change in the base sequence of a gene.
• Even a tiny mutation, like a single base substitution, can change a codon.
  • Real-world example: It's like changing a single letter in a word— "cat" could become "hat". The meaning is entirely different!

When a codon changes, it may code for a different amino acid.

• Especially if the first or second base of the codon changes.
• A single base change can lead to one amino acid being different in a protein.
• Real-world example: Imagine using sugar instead of salt in a cookie recipe by mistake. The outcome (cookie) is going to taste very different!

• How it happens: A single base substitution in the Hb gene.
  • Normal gene (allele): HbA
  • Mutated gene: From GAG to GTG, becomes HbS.
• Why it matters

  • Normal: 6th codon = GAG → Amino acid = glutamic acid.

  • Mutation: 6th codon = GUG → Amino acid = valine.

  • Real-world analogy: It's like swapping a crucial puzzle piece with another from a different puzzle. The whole picture gets distorted!

  • In low oxygen areas, mutated haemoglobin forms chains, turning red blood cells into sickle shapes. 🌙

  • Sickle cells can block blood flow in capillaries, harming tissues.

  • Good news? In high oxygen areas (like the lungs), these cells return to normal.

  • Bad news? Repeated reshaping damages cells, reducing their lifespan to around 4 days. That's super short!