The globular head is/has

1. An active ATPase enzyme

2. Binding sites for ATP

3. active sites for actin

4. All of these

The head part of the HMM of muscle fiber is

1. Globular

2. Triangular

3. Filamentous

4. Both 2 and 3

The above figure is related with myosin monomer (meromyosin). Identify A to C:

(1) A - head, B - cross arm, C - GTP binding sites

(2) A - head, B - cross arm, C - Ca⁺² binding sites

(3) A - head, B - cross arm, C - ATP binding sites

(4) A - cross arm, B - head, C - ATP binding sites

Skeletal muscles appear striated due to the presence of two characteristic proteins in alternating dark and light bands. Which of the following is a correct match of the protein with its light refractive property and color?

       Protein                  Colour                 Property

(1)  Myosin                   Light                 Anisotropic

(2)  Actin                      Dark                 Anisotropic

(3)  Myosin                   Dark                  Isotropic

(4)  Actin                      Light                  Isotropic

In the rest state, a subunit of Troponin masks

1. Active binding sites for actin on the myosin filaments

2. Active binding sites for myosin on the myosin filaments

3. Active binding sites for myosin on the actin filaments

4. Active binding sites for actin on the actin filaments

Following is the figure of actin (thin) filaments. Identify A, B and C:

1. A - Tropomyosin, B - Troponin, C - F-actin

2. A - Troponin, B - Myosin, C - Tropomyosin

3. A - Troponin, B - Tropomyosin, C - Myosin

4. A - Troponin, B - Tropomyosin, C - F-actin

Myosin filaments are:-

1. thin filament 

2. found only in I band

3. absent from H zone

4. attached to M line

Which one of the following pairs of chemical substances, is correctly categorised?

In a myosin molecule HMM (heavy meromyosin) is
present in
(i) Globular head (ii) Short arm (iii) Myosin tail

1. (i), (ii), (iii) 

2. (i) only

3. (i), (ii) only 

4. (iii) only

The globular head of the myosin filament has active site/s for binding to:

 I. ATP

II. the binding site for actin filament 

III. Calcium

1. Only I

2. Only I and II

3. Only II and III

4. I, II, and III