Nitrogen Cycle Flashcards
What are the 6 processes in the nitrogen cycle?
- Nitrogen fixation
- Feeding
- Decomposition
- Nitrification
- Active transport
- Denitrification
What is most of the nitrogen in plants and animals in the form of?
Amino acids and protein.
What is most of the nitrogen in the environment in the form of?
Nitrogen gas and soluble nitrates.
What is the name of the special group of bacteria that converts nitrogen gas into nitrates in the root noodle of legumes?
Nitrogen-fixing bacteria
In the process of nitrogen fixation, how does the bacteria benefit?
They gain carbohydrates when they photosynthesise
In the process of nitrogen fixation, how does the legume benefit?
The legumes gain nitrates from the bacteria which they use to make proteins.
Nitrogen fixation: anaerobic or aerobic?
Aerobic
How does feeding work?
Plants absorb nitrates from the soil they turn it into protein. Animals then feed on the plant protein, allowing the cycle to continue.
How does decomposition work?
Plants and aminals die. They are decomposed by bacteria and fungi. This turns their nitrogen containing protein into AMMONIA.
What is nitrification?
The conversion of ammonia to nitrates and is carried out by nitrifying bacteria in the soil.
Nitrification: aerobic or anaerobic?
Aerobic
Explain active transport?
Plants take in soluble nitrates by active transport in their root hair cells. AGAINST THE CONCENTRATION GRADIENT. It requires energy from respiration.
Denitrification: anaerobic or aerobic?
Anaerobic
What happens with denitrification?
In waterlogged conditions denitrifying bacteria in the soil will convert nitrates into nitrogen gas.
What does denitrification lead to?
A reduced amount of nitrates available for plants which is why many plants struggle to grow in waterlogged soil.
