Step 2: Analyze the given equations. The first equation represents the process of cellular respiration: $\mathrm{C_6H_{12}O_6} + 6\,\mathrm{O_2} \rightarrow 6\,\mathrm{CO_2} + 6\,\mathrm{H_2O} + \text{energy}$. The second equation represents photosynthesis, which is the reverse of cellular respiration. The third equation represents the breakdown of hydrogen peroxide ($\mathrm{H_2O_2}$), and the fourth equation represents fermentation, a process that occurs in the absence of oxygen.