Question

3. If muscle contraction were an athletic game, calcium would be the most valuable player. Describe,

using some depth, the roles calcium is serving both inside the muscle fiber and outside at the NMJ.

Answer 1

Step-by-step explanation:

At the NMJ, calcium is responsible for "unlocking" the ligand gated channels, allowing AcH to be released into the synaptic cleft. When AcH binds and the AP moves down the sarcolemma and into the t-tubule, calcium is then released from the sarcoplasmic reticulum into the sarcoplasm. It then binds to the calcium subunit of troponin, causing a confirmational change in tropomyosin, exposing the active sites on actin. This allows the myosin heads to bind, causing muscle contraction.