Glycoprotein group 3 subtypes include which two primary categories?

• A. Neutral glycoproteins and Sialomucins
• B. Epithelial mucins and neutral mucins
• C. Mucins and mucopolysaccharides
• D. Sialomucins and mucopolysaccharides

Answer: (A)

Glycoprotein groups of mucins are distinguished by charge and sialylation. Neutral glycoproteins have no net negative charge, while sialomucins are acidic mucins rich in sialic acid, giving them a negative charge. Group 3 specifically includes these two categories: neutral glycoproteins and sialomucins. This pairing reflects how these mucins behave histochemically and in staining, with neutral mucins typically contrasting with acidic ones like sialomucins. The other options mix categories that aren’t defined together as Group 3, such as mucopolysaccharides (not glycoproteins) or epithelial mucins as a separate pairing.