Chemical substance secreted at the synapse and helpful in passing impulse from
neuron through a gap is

Options

A. Acetylcholine
B. ATP
C. Cholecytokinin
D. Cholesterol

Answer

To answer the question regarding the chemical substance secreted at the synapse that helps in passing impulses from one neuron through a gap, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a chemical substance that is secreted at the synapse and is involved in transmitting nerve impulses between neurons.

2. **Identify Key Terms**: The key terms in the question are "chemical substance," "synapse," and "impulse." A synapse is the junction between two neurons where communication occurs.

3. **Recall the Function of Synapses**: At a synapse, neurons communicate through the release of neurotransmitters. These are chemical messengers that transmit signals across the synaptic cleft (the gap between neurons).

4. **Consider the Options Provided**:
- **Acetylcholine**: A well-known neurotransmitter involved in transmitting signals in the nervous system.
- **ATP**: Primarily known for providing energy, not for transmitting signals between neurons.
- **Cholecystokinin**: A hormone involved in digestion, not in neural transmission.
- **Cholesterol**: A lipid that plays roles in cell membranes and hormone production, not in neurotransmission.

5. **Evaluate the Options**: Among the options, acetylcholine is specifically recognized as a neurotransmitter that is released at the synapse and facilitates the transmission of nerve impulses.

6. **Select the Correct Answer**: Based on the evaluation, the correct answer is **acetylcholine**.

### Final Answer:
The chemical substance secreted at the synapse that helps in passing impulses from one neuron through a gap is **acetylcholine**.

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