The physical space between the presynaptic and postsynaptic neurons is called the
and the chemical that is released to signal across this space is called a

The physical space between the presynaptic and postsynaptic neurons is called the  synaptic cleft

and the chemical that is released to signal across this space is called a neurotransmitter

Explanation:

A synapse is the junction between dendrites of two adjacent neurons. Its function is to allow the transmission of nerve impulses from neurone to neurone. Tn the presynaptic knob there are vesicles which contain a transmitter substance which is usually acetylcholine. The acetylcholine diffuses from the presynaptic membrane to the postsynaptic membrane.

cellular respiration oxidizes food into energy in the form of atps.

glycolysis (6 c hexose) > 2x atps are used > 6c hexose biphosphate > 2 x 3c triphosphate >

2 x 3c pyruvate (2x nadh produced from nad) and (4x atp produced)

pyruvate actively pumped mitochondrial matrix.