Final answer:
Haemoglobin can carry iron ions that fluctuate in charge, but it itself is not simply categorized as a positively charged sol. It forms colloidal suspensions within red blood cells and alterations in its structure can lead to diseases such as sickle-cell anemia.
Step-by-step explanation:
Haemoglobin is not necessarily a positively charged sol. It is a complex protein existing in red blood cells that is responsible for transporting oxygen throughout the body. The charge of haemoglobin can vary depending on the environmental pH and the presence of oxygen. Each of the four subunits in hemoglobin can carry an iron ion, which changes its oxidation state from +2 to +3, depending on whether oxygen is bound to the iron or not. This does not equate directly to haemoglobin being a positively charged sol but rather indicates the ability of iron within hemoglobin to change its charge during oxygen transportation.
In colloidal chemistry, a sol is a type of colloid made of very small particles suspended within a continuous medium. Hemoglobin itself can form stable colloidal suspensions within red blood cells, which are crucial for their function and flexibility. However, modifications in hemoglobin structure, such as those seen in sickle-cell anemia, can lead to the aggregation of hemoglobin molecules and subsequent red blood cell deformation.
Therefore, while iron within hemoglobin can exhibit positive charges, it is not accurate to simply categorize hemoglobin as a positively charged sol without considering the specific conditions and chemical environment.