ExplainerTools

Short · Biology

Why does oxygen let go?

Lower oxygen pressure and watch modeled hemoglobin saturation fall; cooperative binding helps explain loading and unloading.

Try it yourself

Opens Hemoglobin Handoff. Change the same thing yourself.

Narrated · 35 seconds · captions includedDownload the film

Keep exploring

Up next

  1. InteractiveHemoglobin HandoffChange the same thing yourself.Try it yourself
  2. 0:37Short · SpaceWhy are the northern lights green?
  3. 0:37Short · EarthWhy doesn't a compass point to the North Pole?

Transcript

Why does oxygen let go? Lung oxygen pressure is high. Hemoglobin can bind four oxygen molecules. Binding shifts its shape; the next oxygen binds more easily. Lower pressure from 100 to 40 millimeters of mercury. Watch saturation fall from about 97 percent to 75. That steep curve is cooperative binding: losing one oxygen makes the next easier to release. Reference conditions are fixed here. Try it yourself at Explainer Tools dot com.