Animals obtain their nitrogen from bacteria, nitrates plants, nitrites
plants obtain their nitrogen from the soil or water, and animals obtain their nitrogen from the plants they consume or from other animals.
In the soil, nitrogen exists in various forms, including nitrates, nitrites, and ammonia. Bacteria, particularly nitrogen-fixing bacteria, play a crucial role in the nitrogen cycle by converting atmospheric nitrogen into these forms that are usable by plants. These bacteria live in the soil and have the ability to convert atmospheric nitrogen gas (N2) into ammonium (NH4+), a process called nitrogen fixation.
Plants absorb nitrates and nitrites from the soil through their root systems. Once inside the plants, these nitrogen compounds are used to synthesize amino acids, proteins, and other nitrogen-containing compounds essential for their growth and development. Nitrate ions (NO3-) are the most commonly absorbed form of nitrogen by plants.
When animals eat plants or other animals, they obtain the nitrogen present in these organic compounds. Animals digest and break down these nitrogen-containing molecules into amino acids, which are used to build proteins and other necessary molecules in their own bodies. Nitrogen is an essential element for animals to form DNA, RNA, and other biological molecules that are critical for their growth, reproduction, and overall health.
Thus, bacteria play a vital role in converting atmospheric nitrogen into usable forms for plants, which in turn provide nitrogen for animals through their consumption. This interconnected process ensures the continuous cycling of nitrogen in ecosystems.