In which phase of the ACh life cycle is ACh protected from degradation?

Acetylcholine (ACh) is a neurotransmitter that plays a critical role in the transmission of signals in the nervous system. The correct phase during which ACh is protected from degradation is when it is taken up into storage.

During the life cycle of ACh, after it is synthesized in the presynaptic neuron, it is packaged into vesicles within the neuron. This storage phase is essential because it keeps ACh in a stable form and protects it from enzymatic degradation that could occur if it were free in the cytoplasm. These vesicles are designed to safeguard ACh until it is needed for transmission across the synapse.

Once ACh is released into the synaptic cleft, it is exposed to enzymes like acetylcholinesterase, leading to its rapid degradation unless it has been taken up into storage beforehand. Therefore, keeping ACh in storage vesicles prevents it from undergoing degradation, allowing for efficient and effective transmission of neural signals when needed.