Making Glucose: light energy splits water molecules into hydrogen atoms and oxygen atoms. The hydrogen atoms combines with a chemical called nicotinamide-adenine dinucleotide phosphate (NADP) to form NADPH2, which is used later in the dark reaction. The oxygen atoms bind to each other and molecular oxygen (O2) is released into the atmosphere. Also, the light energy is used to produce the energy molecule called adenine triphosphate (ATP), which is also used in the dark reaction. So, the main products of the light reaction are NADPH2, ATP, and O2. During the dark reaction, enzymes use the energy from NADPH2 and ATP (formed in the light reaction) to convert carbon dioxide (CO2), obtained from the atmosphere, into glucose and water. The glucose and water can be stored for future use by the plant.
Breaking Glucose: Glucose is actively transported through the membranes of both the chloroplasts and the mitochondria. Once inside the mitochondria, cellular respiration now begins. The reaction takes place in the Cristae. Glucose will be broken down and carbon dioxide and water are the products of the reaction. Carbon dioxide leaves the mitochondria. Part of the carbon dioxide is recycled again through chloroplasts. Break down of glucose also produces chemical energy that is used throughout the entire body for cell and enzyme functions such as being able to live. The energy is called ATP (adenosine triphosphate). It has three instead of just the one phospate present in DNA. The other two phosphates have high energy bonds. Water, like carbon dioxide, is recycled to other parts of the organism. It too can be eliminated. Once ATP is used for energy it loses a phosphate and becomes ADP.