The energy released in cellular respiration was originally present in

glucose molecules

The chemical energy of "food" molecules. This is better known as glucose molecules. Look at the equation below for an explanation.

Explanation:

glucose + oxygen > carbon dioxide + water

   reactants                    products

- The glucose is broken down for energy.

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answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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