Question

read the following paragraph from the section carbs, proteins and fats. the cycle allows us to use the energy found in carbohydrates, proteins and fats. although the citric acid cycle does not use oxygen directly, it only works when oxygen is around. this cycle takes place in the mitochondria of the cell. which idea is best supported by this paragraph? (a) the presence of oxygen can sometimes impede the citric acid cycle of cellular respiration. (b) carbohydrates, proteins and fats do not contain oxygen molecules needed for the citric acid cycle. (c) the citric acid cycle will not occur unless oxygen is present within the mitochondria of the cell. (d) oxygen is the main ingredient that the citric acid cycle converts and uses to make its final product.

Explanation:

The paragraph states that the citric - acid cycle only works when oxygen is around and takes place in the mitochondria. This implies that the cycle won't occur without oxygen in the mitochondria. Option A is incorrect as oxygen is necessary, not an impeder. Option B is not supported by the text. Option D is wrong because oxygen is not a reactant in the cycle but a requirement for it to function.

Answer:

C. The citric acid cycle will not occur unless oxygen is present within the mitochondria of the cell.