🎈 Did you know? Just like you sometimes can't choose between pizza and ice cream, haemoglobin faces choices too! It can't always cling to oxygen, especially when our muscles are hard at work. This is all thanks to our friend - the Bohr shift!

When you're sprinting or doing that intense dance-off, your muscles work extra hard. They breathe in a lot (aerobic respiration), releasing more CO₂ into your blood. Here's the kicker: More CO₂ means haemoglobin doesn't hold onto oxygen as tightly. Why? Two cool reasons!

• CO₂ meets up with H₂O in our red blood cells. They mingle and form hydrogen ions (H+) and hydrogen carbonate ions (HCO³⁻).
• CO₂ + H₂O → H+ + HCO³⁻
• This mix makes the blood a bit more acidic (lower pH).

🍋 Real World Example: It's like adding a squeeze of lemon to water. The water gets a tangy taste (acidic). Now imagine this happening inside us! In our lungs, the pH is around 7.4 (neutral, like plain water), but in hard-working muscles, it's around 7.2 (a bit more acidic, like that lemon water). This difference makes it easier for oxygen to bind with haemoglobin in the lungs and let go in active muscles.