Final answer:
Carrier molecules during cellular respiration, specifically in the Krebs Cycle, include NAD and FAD which are reduced to NADH and FADH2, respectively. These molecules carry electrons to the Electron Transport Chain to generate ATP, the cell's energy currency. The answers are options 1 and 2.
Step-by-step explanation:
During cellular respiration, specifically in the Krebs Cycle, the carrier molecules involved are NAD (Nicotinamide adenine diphosphate) and FAD (Flavin adenine dinucleotide). Both of these molecules play crucial roles in the process of transferring electrons. NAD and FAD are reduced to NADH and FADH2, respectively, when they accept electrons during the Krebs Cycle. These reduced forms then carry the electrons to the Electron Transport Chain, where they are used to generate a large amount of ATP - the energy currency of the cell.
In summary, each turn of the Krebs Cycle results in the production of one ATP, one FADH2, and three NADH molecules which will later enter the oxidative phosphorylation system to produce more ATP. Furthermore, during the complete oxidation of glucose, a total of ten NADH and two FADH2 molecules are formed, which are essential for ATP synthesis in the later stages of cellular respiration.