Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose and oxygen. However, under certain environmental conditions, some plants can increase their rate of CO2 fixation through a process called cassulacean acid metabolism (CAM). Explain the chemical mechanisms behind CAM photosynthesis, including the role of stomata, the temporal separation of CO2 uptake and fixation, and the specific adaptations that CAM plants possess to thrive in arid environments. How does CAM provide an advantage over the C3 pathway used by most plants, particularly in terms of water conservation?