AP BIOLOGY

Detailed explanation-1: -Why is this so? Because plants and animals are not able to use nitrogen gas in that form. For nitrogen to be available to make proteins, DNA, and other biologically important compounds, it must first be converted into a different chemical form.

Detailed explanation-2: -This is really important because plants and other organisms present in the soil can’t directly use the atmospheric nitrogen (N2). The fixation process converts nitrogen (N2) into ammonia, which can then be metabolized by most of the organisms.

Detailed explanation-3: -Nitrogen-fixing bacteria in the soil and within the root nodules of some plants convert nitrogen gas in the atmosphere to ammonia. Nitrifying bacteria convert ammonia to nitrites or nitrates.

Detailed explanation-4: -Plants can use ammonia as a nitrogen source. After ammonium fixation, the ammonia and ammonium that is formed will be transferred further, during the nitrification process. Aerobic bacteria use oxygen to convert these compounds.

Detailed explanation-5: -Nitrogen is an essential macronutrient for plant function and is a key component of amino acids, which form the building blocks of plant proteins and enzymes. Proteins make up the structural materials of all living matters and enzymes facilitate the vast array of biochemical reactions within a plant.