Final answer:
Photosynthesis can be affected if a plant does not receive enough sunlight or if there is a lack of carbon dioxide.
Step-by-step explanation:
In photosynthesis, plants use sunlight, carbon dioxide, and water to produce glucose and oxygen. If a plant does not receive enough sunlight, the part of the chemical reaction that would be affected is the light-dependent reactions. Without sufficient sunlight, energy cannot be converted into stored chemical energy, and the process of photosynthesis cannot proceed.
Additionally, if there is not enough carbon dioxide available, the production of glucose would be affected. Carbon dioxide is one of the reactants in photosynthesis, and without enough of it, the plant would not be able to produce glucose.
In summary, the part of the cheical reaction affected by the lack of sunlight is the light-dependent reactions, and the part affected by the lack of carbon dioxide is the production of glucose.