Question

Explain how enzymes within synaptic clefts and re-uptake of neurotransmitters prevent continuous stimulation of the post-synaptic cell (p. 381).

A) Enzymes in the synaptic cleft break down neurotransmitters, preventing their re-uptake by the post-synaptic cell.
B) Enzymes within synaptic clefts degrade neurotransmitters, allowing them to be stored for future use by the post-synaptic cell.
C) Re-uptake of neurotransmitters by the post-synaptic cell ensures continuous stimulation, and enzymes play no role in this process.
D) Enzymes in the synaptic clefts neutralize neurotransmitters, halting their effect on the post-synaptic cell.

Answer 1

Enzymatic degradation and reuptake are two processes that prevent continuous stimulation of the post-synaptic neuron. Enzymes break down neurotransmitters in the synaptic cleft, while reuptake absorbs neurotransmitters back into the pre-synaptic neuron.Hence, option D is the correct answer.

Step-by-step explanation:

Enzymes in the synaptic cleft play a crucial role in preventing continuous stimulation of the post-synaptic neuron. Once a neurotransmitter has bound to receptors on the post-synaptic cell, it needs to be cleared from the synaptic cleft to reset the synaptic transmission process. Enzymatic degradation occurs when specific enzymes within the synaptic cleft break down neurotransmitters, which terminates the signal by preventing any further interaction with post-synaptic receptors. Meanwhile, reuptake is a process where the neurotransmitter is absorbed back into the pre-synaptic neuron. This process also serves to prevent continuous stimulation by removing the neurotransmitter from the synaptic cleft, thereby clearing the synapse and allowing it to return to a 'ready' state.

Therefore, the correct explanation is that enzymes within synaptic clefts degrade neurotransmitters, and reuptake of neurotransmitters by the pre-synaptic cell prevents continuous stimulation of the post-synaptic cell, making the best answer option D).