Final answer:
Band 3 is a glycoprotein complex in red blood cells that exchanges chloride and bicarbonate ions to help maintain acid-base balance. It is crucial for understanding blood transfusions and antigens.
Step-by-step explanation:
Band 3 is a protein complex in red blood cells that is responsible for the exchange of chloride (Cl-) and bicarbonate (HCO₃⁻) across the cell membrane. This function is essential for maintaining the acid-base balance in the blood. Band 3 is a glycoprotein that forms as two homodimers, which means it consists of two identical subunits that come together to perform its function.
The antigens and glycoproteins on the surface of red blood cells, like those in the ABO and Rh blood groups, play a pivotal role in blood transfusions as they can elicit immune responses when foreign antigens are introduced into the body. Therefore, understanding the function and structure of blood cell glycoproteins is crucial in medicine, particularly in the context of blood transfusions and immunology.