vault backup: 2025-11-28 09:51:15

content/Biokemi/Gamla tentor/2023-12-18/4.md

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+---
+tags:
+  - biokemi
+  - provfråga
+  - hemoglobin
+---
+**What does cooperative binding mean? Explain this in the context of hemoglobin. (4p)**  
+*OBS! This question needs to be answered in English. (Max 100 words)*
+
+**Answer**
+
+Cooperative binding means that the binding of an oxygen to hemoglobin makes it more likely for the molecule to bind more oxygen.  
+This is because when an oxygen binds to hemoglobin the structure becomes less tense as one αβ-dimer rotates 15 degrees, which increases its affinity for oxygen at other binding sites.  
+Release of an oxygen promotes also further release.  
+Due to the cooperativity hemoglobin has a sigmoidal binding curve at different partial pressures of oxygen.  
+Cooperativity enables hemoglobin to be a good oxygen transporter.