Answer:
Cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and discarding, as waste products, carbon dioxide and water.
Release of a neurotransmitter across the synapse is triggered by the entry of Ca++ into the presynaptic axon. No Ca++ entry means no transmission across the synapse.
There are four major classes of biological macromolecules:
carbohydrates.
lipids.
proteins.
nucleic acids.
<span>The sum total of all the chemical reactions that occur in organisms is called-</span>Metabolism
