Question

Which substances below could be observed either entering or leaving a mitochondrion?

Oxygen

Pyruvate

Glucose

Adenosine Triphosphate

CO2

Carbon monoxide gas

a) 1, 2, 3, 4, 5, 6
b) 2, 3, 4
c) 1, 5, 6
d) 3, 4, 2

Answer 1

Substances entering or leaving a mitochondrion include oxygen, pyruvate, ATP, and CO2, which are all involved in cellular respiration. Glucose is processed outside the mitochondria and carbon monoxide is not involved in the process.

Step-by-step explanation:

The substances that can be observed either entering or leaving a mitochondrion are oxygen, pyruvate, Adenosine Triphosphate (ATP), and CO2 (carbon dioxide). Oxygen and pyruvate are reactants in cellular respiration, with oxygen serving as the final electron acceptor in the electron transport chain, which produces water. Pyruvate, derived from glucose, enters the mitochondria and is transformed into acetyl CoA, which enters the Krebs cycle, releasing CO2 as a waste product. ATP is the major energy currency of the cell that is produced in the mitochondria during cellular respiration. Carbon monoxide gas is not a product or reactant of cellular respiration and therefore would not be expected to be observed entering or leaving mitochondria under normal physiological conditions. Hence, the correct answer to substances observed either entering or leaving a mitochondrion is:

Option b) 1, 2, 4, 5 - Oxygen, Pyruvate, Adenosine Triphosphate, CO2.