Maize seedlings were grown with different levels of nitrate to see how it affects certain enzymes in the leaves. The enzymes nitrate reductase, nitrite reductase, glutamine synthetase, GOGAT, and NADH-glutamate dehydrogenase were studied. The activity of these enzymes changed depending on the amount of nitrate given to the plants. Some enzymes increased in activity with more nitrate, while others decreased. The enzymes were grouped based on their response to nitrate levels. The study found that the activity of some enzymes was closely related to the growth of the leaves, while others were not. Additionally, the activity of one enzyme was higher in certain parts of the leaf compared to others.