In the liver, excess amino acids are broken down into and rapidly combine with to produce urea, which is much less toxic to cells.

into - ammonia (Ammonium ions)

with - enzymes.

In the liver, excess amino acids are broken down into ammonia and rapidly combine with carbon dioxide to produce urea, which is much less toxic to cells.

Explanation:

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.