Correct option is C
Explanation of the correct answer:
The correct answer is Option 3 because this statement is incorrect. Here's why:
(1): Human chorionic gonadotropin (hCG) contains galactose and hexosamine in its structure. These are sugar residues that are part of the glycosylation of the protein, and this is correct.
(2): The α-subunit of hCG is identical to the α-subunit of TSH (thyroid-stimulating hormone), LH (luteinizing hormone), and FSH (follicle-stimulating hormone). The α-subunit is common to all these glycoprotein hormones, and this statement is correct.
(3): The β-subunit of hCG is larger than the α-subunit, not smaller. The β-subunit confers the specificity of the hormone, and it differs between hCG, TSH, LH, and FSH. The β-subunit of hCG is larger because it contains unique amino acid sequences that allow hCG to exert its biological effects. This makes Option 3 the incorrect statement.
(4): hCG is primarily luteinizing in nature because it mimics LH (luteinizing hormone), which is responsible for stimulating the corpus luteum to produce progesterone during early pregnancy. Therefore, this statement is correct.
Information Booster:
Glycosylation of hCG: hCG has an extensive glycosylation pattern, which includes sugars like galactose and hexosamine. These sugar groups are important for the stability and biological activity of the hormone.
α- and β-subunits: The α-subunit of hCG is identical to that of LH, TSH, and FSH, while the β-subunit is unique to each hormone and provides specificity. The β-subunit of hCG is larger and contains amino acid sequences that allow it to interact with its receptor on the luteal cells.
