Question

If blood is Negatively charged sol and haemoglobin is positively charge sol, then why they do not coagulate?

Answer 1

This is because haemoglobin is contained only inside the RBCs -: outside in bloodstream these are highly toxic. RBC membarene has - vely charged phospholipid heads which further prevents induction of the +ve charge on its surface, thus separating the charge from the colloid.

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