Question

Match the following.

Column I Column II
i.Troponin a.Blocks the attachment site for the myosin cross bridge
ii.Tropomyosin b.Has a myosin binding site
iii.Actin c.Complex of 3 polypeptide units

• A. i).→ c ., ii). → b., iii). →a
• B. i). →b., ii). → a., iii). →c
• C. i). → c., ii). → a., iii). →b
• D. i) →a., ii). → c., iii). →b

Answer 1

The correct option is C

i). → c., ii). → a., iii). →b

The thin filament is made of three separate proteins: actin, troponin, and tropomyosin. Actin has a myosin binding site for the cross bridge formation.
Troponin is a complex of three Polypeptide units(Troponin C, I and T). In a relaxed muscle, tropomyosin blocks the attachment site for the myosin cross bridge, thus preventing contraction.