If a Muscle Fiber Were to Suddenly and Permanently Stop

question 28

Multiple Choice

If a muscle fiber were to suddenly and permanently stop producing ATP the fiber would no longer be able to actively transport calcium out of the cytoplasm (sarcoplasm) and the intracellular calcium concentration would rise.Which of the following would you expect to happen?

• A) The fiber would twitch uncontrollably due to excessive calcium bound to troponin.
• B) Myosin would be able to bind to the exposed binding sites on thin filaments but it would not be able to detach.
• C) Calcium would be transported to the sarcoplasmic reticulum therefore contractions would cease.
• D) No change would occur in a muscle that was relaxed to begin with.

---

Definitions:

Corpus Callosum

A broad band of nerve fibers joining the two hemispheres of the brain, facilitating communication between them.

Cerebrum

The largest part of the brain, responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.

Cerebral Cortex

The outer layer of the brain's cerebrum, involved in complex brain functions such as thought, memory, and consciousness.

Parietal Lobes

Regions of the brain located behind the frontal lobes and above the occipital lobes, involved in processing sensory information from various parts of the body, understanding spatial orientation, and managing language and mathematics.