What are proteins that act to speed up chemical reactions? a.

Enzymes

c.

Glycerol

b.

Amino Acids

d.

Polysaccharides

Enzymes because they are proteins that act as catalysts within living cells. Catalysts increase the rate at which chemical reactions occur without being consumed or permanently altered themselves.

Hope this helps! Please correct me if I'm wrong :)

enzyme would break down

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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