Question

A graph showing the energy of the reactants and products of cellular respiration is shown here. Which description accurately compares the products and reactants of cellular respiration in terms of energy level?
Responses
A Glucose is a reactant and has less energy than carbon dioxide, a product.Glucose is a reactant and has less energy than carbon dioxide, a product.
B Oxygen gas and glucose are products and have a lower energy level than the reactants.Oxygen gas and glucose are products and have a lower energy level than the reactants.
C Water and carbon dioxide are products and have a lower energy level than the reactants.Water and carbon dioxide are products and have a lower energy level than the reactants.
D Oxygen gas in a reactant, and has the same energy as the water molecule that is produced.

Answer 1

C

Water and carbon dioxide are the products of cellular respiration and have lower chemical energy than the reactants (glucose and O2). Cellular respiration is an exergonic process: energy stored in glucose (and O2) is released as ATP and heat, leaving the products (CO2 and H2O) at a lower energy level.