Which one of the following pairs of chemical substances, is correctly categorised?
1. | Pepsin and prolactin - Two digestive enzymes secreted in the stomach |
2. | Troponin and myosin - Complex proteins in striated muscles |
3. | Secretin and rhodopsin - Polypeptide hormones |
4. | Calcitonin and thymosin - Thyroid hormones |
The contractile protein of skeletal muscle involving ATPase activity is:
1. tropomyosin
2. myosin
3. α-actinin
4. troponin