How do plants get nitrogen to synthesize proteins?
Plants suck up nitrogen from the dirt with their roots. It's not from the air. Bacteria in the soil help make the nitrogen good for them.
I like to explain it this way: - Plants are like chefs, they need ingredients. - Nitrogen gas is locked, like a closed jar. - Bacteria act like can-openers, unlocking nitrogen into nitrates. - Plants then “cook” proteins from these nitrates.
Nitrogen cycle plays a role:- Bacteria fix atmospheric nitrogen into usable forms. - Fertilizers add nitrates to soil. - Roots absorb these. - Inside plant cells, they are reduced to ammonia, then combined into amino acids.
Plants cannot directly use nitrogen gas (N₂) from the atmosphere. Instead, they absorb nitrates (NO₃⁻) and ammonium (NH₄⁺) ions from the soil, which are converted into amino acids, then proteins.
Leguminous plants (beans, peas) have rhizobium bacteria in root nodules. These fix nitrogen directly, giving legumes a nitrogen advantage. That’s why farmers rotate crops.