Nitrogen in Ecosystems Flashcards
Nitrogen cycle
This set of cards needs to be worked through in order.
They will help you to revise the nitrogen cycle by building up a diagram of it.
Which chemicals are made, by all living things, using Nitrogen?
Amino acids, which are built into proteins.
Lets think about why proteins are important to cells.
What are they used for?
To make:
- Structures in the cell, including the cell membrane.
- Enzymes.
Lets start building up the Nitrogen cycle starting with Plant protein.
What happens to the protein present in plants?
- Eaten by animals
- Broken down when the plant dies.
What happens to the animal protein?
- Passes out in urine (and faeces)
- Will be broken down when the animal dies
What are the plant and animal proteins converted into, in the soil?
Ammonium
Ammonium is converted into ……. and then ……..
Nitrite and then Nitrate
The nitrate is then absorbed by the plant.
Which part of the plant absorbs the nitrate?
Root hairs
Once inside the plant the Nitrate is used to produce ….
Amino acids, which are built up into Plant Protein.
This completes the basic Nitrogen Cycle!!
Using the information on the last 8 cards, draw out the basic Nitrogen cycle.
It should look something like this:
What name is given to the set of reactions from Ammonium to Nitrate?
Nitrification
Add this label to your diagram.
There is a lot of Nitrogen gas in the air but plants can’t use it directly.
What is the name of the process that puts N2 gas, from the air, into the Nitrogen cycle?
Nitrogen fixation
Name the two places where nitrogen fixing bacteria are found.
- Free-fixing bacteria in the soil (producing ammonium)
- Inside root nodules of some plants (making nitrates for the plant to use).
Name the chemical, containing nitrate, which farmers and gardeners add to the soil to impove plant growth.
Fertiliser
Name the bacteria that convert Nitrates back into N2 gas in the air.
Denitrifying bacteria