Question

multiple choice question
once the acetylcholine binds to the receptors on the sarcolemma it triggers the release of ___ from the sarcoplasmic reticulum.
o ca²⁺
o atp
o na

Explanation:

When acetylcholine binds to receptors on the sarcolemma, it initiates an electrical signal that leads to the release of calcium ions ($Ca^{2+}$) from the sarcoplasmic reticulum. This is a key step in muscle contraction as calcium ions then bind to troponin - causing a conformational change that exposes binding sites for myosin on actin filaments. ATP is involved in the energy - supply for muscle contraction but is not released from the sarcoplasmic reticulum in response to acetylcholine binding. Sodium ($Na$) is involved in the initial depolarization of the sarcolemma but not released from the sarcoplasmic reticulum at this stage.

Answer:

Ca²⁺