Are the oxygen atoms a runner exhales the same oxygen atoms she inhaled from the environment?

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.

light dependent reactions:

light independent reactions:

hope this !

explanation:

the sun shines white and black light to our planet. the white light has all the colors in it. in our upper atmosphere, we have dust particles and oxygen molecules. the white light meaning all of the colors in a rainbow shines through the upper levels of the atmopshere and the blue light scatters across the entire planet. that is why our sky is blue.