Final answer:
Phosphoglycolate is a competitive inhibitor of carbon dioxide fixation, leading to a reduced rate of photosynthesis in plants.
Step-by-step explanation:
Phosphoglycolate is a competitive inhibitor of carbon dioxide fixation in photosynthesis, which leads to a reduced rate of photosynthesis. When phosphoglycolate is formed instead of a normal product in the Calvin cycle, it needs to be converted back into a usable molecule. This process consumes energy and reduces the efficiency of photosynthesis.