1. THE NITROGEN CYCLE

2. NITROGEN

3. NITROGEN QUICK FACTS N Carbon = Energy, Nitrogen = Building Blocks7 N
14.01
Carbon = Energy, Nitrogen = Building Blocks
We use nitrogen to build proteins
We use it to build each piece of DNA
It’s the #1 gas in the atmosphere – 78%
Maybe a little bird flying out of the tree

4. Where do you find it? Air Live Plants Live Animals Soil Animal Waste
Dead Animals
& Plants
R.I.P.
“Animal”
R.I.P.
“Plant”

5. Where else is it found?
Oceans

6. Where else is it found?
Fertilizers

7. N2 Nitrogen always comes in pairs when in the air…
… we call this atmospheric nitrogen (N2)
But most living things can’t use atmospheric nitrogen… N2
REJECTED
REJECTED

8. Luckily there are some kinds of bacteria that can change the nitrogen in the air…
into forms that plants can use
All animals trace their nitrogen back to plants N2
Accepted!
Usable
Nitrogen
Accepted!
Bacteria… not to scale

9. Nitrogen Fixing Bacteria
Bacteria changing N2 into a form that can be used by plants is called…
Nitrogen Fixation
And we call the bacteria that does this…
Nitrogen Fixing Bacteria

10. WRONG TO BE CONTINUED That’s it, we’re done, RIGHT?
This is a cycle, remember?

11. Option A
Let’s review - see if you can tell me where “Nitrogen Fixation” is taking place in the process below…
Option D N2
Accepted!
Option B
Would be good to add the whole “Nitro Fix Station” thing here
Usable
Nitrogen
Option C
Accepted!
Bacteria… not to scale

12. So what next? Once the nitrogen goes into animals and plants how does it get out to complete the cycle?
As animal waste and dead organisms are broken down by decomposers, their nitrogen is released back into the soil…
R.I.P.
“Cow”
R.I.P.
“Plant”
Combine poop with this page as well – make more daisies pop up, etc.

13. N2 1. It can be reabsorbed by plants
Two things can happen…
1. It can be reabsorbed by plants
2. A second kind of bacteria can change the nitrogen back into N2 N2
Accepted!

14. Denitrifying Bacteria
The process where bacteria change usable nitrogen back into N2 is called…
Denitrification
And we call the bacteria that do this…
Denitrifying Bacteria

15. Ladies and gentlemen… we have a cycle
Accepted!
R.I.P.
“Cow”
R.I.P.
“Plant”
Stop and draw a simplified version on the board after this
Usable
Nitrogen N2
Accepted!
Bacteria… not to scale

16. Ladies and gentlemen… we have a cycle
Accepted!
R.I.P.
“Cow”
R.I.P.
“Plant”
Stop and draw a simplified version on the board after this
Usable
Nitrogen N2
Accepted!
Bacteria… not to scale

17. Ladies and gentlemen… we have a cycle
Accepted!
R.I.P.
“Cow”
R.I.P.
“Plant”
Stop and draw a simplified version on the board after this
Usable
Nitrogen N2
Accepted!
Bacteria… not to scale

18. 1. Fertilizer Overload 2. Air Pollutants 3. Greenhouse Gases
So how are humans affecting the Nitrogen Cycle?
1. Fertilizer Overload
2. Air Pollutants
3. Greenhouse Gases

19. IT’S OVER!
What else should I know about the nitrogen cycle?
LIGHTENINGED!
Lightening
It would be fun to add – “Fired”, “Lightning” and “Legumed!” to the list as other possible fixators