Final answer:
In cellular respiration, carbohydrates, fats, and sugars are oxidized to carbon dioxide and water, ultimately releasing energy used to synthesize ATP. This complex process includes stages such as glycolysis, the Krebs cycle, and oxidative phosphorylation, mainly occurring within the mitochondria.
Step-by-step explanation:
Cellular respiration is a biochemical process in which energy-rich molecules such as carbohydrates, fats, and sugars are oxidized to form carbon dioxide and water, releasing energy that is captured in the molecule ATP (adenosine triphosphate). During cellular respiration, the carbon atoms in a molecule of glucose, which has six carbon atoms, are fully oxidized into carbon dioxide through a series of stages: glycolysis, the Krebs cycle (also known as the citric acid cycle), and oxidative phosphorylation. These stages take place primarily in the mitochondria of eukaryotic cells, except glycolysis which occurs in the cytoplasm.
In the first step of glycolysis, glucose splits into two pyruvate molecules in the cytoplasm. These are further oxidized and converted into Acetyl CoA, which enters the Krebs cycle within the mitochondria, resulting in the complete oxidation of the carbon atoms to carbon dioxide. During oxidative phosphorylation, electrons extracted from the food move down the electron transport chain, driving the formation of ATP. Hence, choice a), choice b), and choice c) from the given options are correct as they all describe oxidation of energy-rich molecules to carbon dioxide and water, while choice d) is incorrect because oxygen is not a product of cellular respiration.