Question

True or False

1. In the normal resting state of a skeletal muscle fiber, myosin has a high affinity for actin but binding is inhibited by the troponin-tropomyosin complex.

2. For the body to increase its amount of muscle mass, a person must be in nitrogen balance.

Choose best answer

1. The type of skeletal muscle contraction that causes movement is:

a. a concentric contraction

b. an isometric contraction

c. an eccentric contraction

d. none of these

2. Endurance overload training (i.e., low power-long duration training) of previously untrained skeletal muscle leads to:

a. an increase in the myofibrillar-to-nonmyofibrillar protein ratio in trained skeletal muscle fibers

b. hypertrophy of the trained muscles

c. increased oxidative capacity of all muscle fibers that are recruited during training, regardless of their types

d. none of these.

Answer 1

Answer 1. True

Troponin normally binds to actin, which keeps tropomyocin positioned. This troponin-tropomyosin complex prevent myosin from binding to actin, and as a result contraction does not occurs.

Answer 2. True

And to do this various supplements are available too.

Answer 1. Option a

Concentric contraction causes shortening of the fibers and this is quite common with skeletal muscles.

For Eg, pulling a dumbbell is an example of concentric contraction and keeping the dumbbell down is an Eccentric contraction. Both are a part of skeletal muscle contraction.

Answer 2. Option b

Hypertrophy occurs in the trained muscles. It refers to the enlargement of the muscle organ by regular training.