Answer:
A. Neurotransmitters can act as ligands.
B. Acetylcholine is a neurotransmitter. It can bind to an acetylcholine receptor on the surface of a cell. If this receptor is also a sodium channel, we would call acteylcholine a ligand and its receptor a ligand gated receptor.
Explanation: 
Answer:
A. Neurotransmitters can act as ligands.
B. Acetylcholine is a neurotransmitter. It can bind to an acetylcholine receptor on the surface of a cell. If this receptor is also a sodium channel, we would call acteylcholine a ligand and its receptor a ligand gated receptor.
Explanation:
Neurotransmitter are chemicals that transfer signals between neurons and nerve cells. They control some physical and physiologocal activity such as appetite, food. 
Acetycoline is an example of neurotransmitter and it is located in the parasympathetic nervous system. Ligand are substance that form complexes with biomolecule. They serve biological purpose with this biomolecule. 
 This ligand binds to target site. Neurotransmitter act as ligand by binding to receptor in the postsynaptic neuron and acetycoline a type of neurotransmitter can also serve as ligand they bind to acetycoline receptor on cell surface.
 
        
             
        
        
        
The answer is D, ADP gains a phosphate and that is used to convert to ATP with a product of ATP and water
        
                    
             
        
        
        
Nitrogen is a fundamental element required during the growth and development of any organism.
- Nitrogen is a fundamental chemical element required to synthesize different biomolecules such as nucleic acids (either DNA or RNA) and proteins.
- Amino acids are the bounding blocks of proteins, whereas nucleotides are the building blocks of nucleic acids, and both contain nitrogen.
- All organisms in their growth phase requires nitrogen in order to synthesize these biomolecules (i.e., nucleic acids and proteins).
In conclusion, Nitrogen is a fundamental element required during the growth and development of any organism. 
Learn more about nitrogen here:
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