Nitrogen
Nitrogen gas makes up 78% of Earth鈥檚 atmosphere and is an essential component in amino acids and proteins.
However, plants and animals cannot use nitrogen gas directly.
Plants can only absorb nitrogen in the form of nitrateThe chemical absorbed from the soil by plants to produce their protein..
Minerals
Nitrates and other minerals are taken into a plant via specially adapted root cells called root hair cells.
They are specially adapted by having a long extension that provides a large surface area for absorption.
Nitrates are absorbed by the process of active uptake/transport, which moves the mineral from an area of low concentration in the soil to an area of high concentration, against a concentration gradient, in the plant root.
Energy (from aerobic respirationRespiration that requires oxygen.) is required to move minerals against the concentration gradientThe difference in concentration between two solutions, between different cells or between cells and a surrounding solution. so this process needs to happen in the presence of oxygen.
Plants use nitrates to make amino acidThe building blocks that make up a protein molecule. and proteins; these are then transferred to animals in the food chainA sequence (usually shown as a diagram) of feeding relationships between organisms, showing which organisms eat what and the movement of energy through trophic levels..