Question

Muscle contraction requires activation of K+ channels that in turn activates which organelle to release internal calcium stores

1. Endoplasmic reticulum
2. Sarcoplasmic reticulum
3. Voltage gated calcium channels
4. GPCR signals
5. None of the above

Answer 1

Sarcoplasmic reticulum is found in muscles, it stores Ca2+ in the muscle cells ( sarcomeres).

The endoplasmic reticulum is found in other cells.

Voltage-gated Ca2+ channels are found at the axon terminals, which open in response to an action potential and allows the inflow of Ca2+ into the axon which is required for the the fusion of neurotransmitter vesicles.

GPCR signals activate the GPCR and induce signaling cascade in the cell.

B) Sarcoplamic retciulum.