Answer: a. Glucose is broken down to pyruvate.
b. Respiration requiring oxygen occurs in the mitochondria.
Step-by-step explanation:
Cellular respiration can be defined as the process in which oxidation of food occurs in the mitochondria and energy is released as ATP. The glucose which is six carbon molecule is most common substrate for oxidation and it is converted into pyruvate which is a three carbon molecule. This is occurs in aerobic cellular respiration. During cellular respiration 30+ ATP molecules are produced which is comparatively more than glycolysis and Kreb's cycle.