March 14, 2013 Q-2 Pg.Daily Goal: We will be able to explain why we never run out of carbon.Homework: Complete your daily carbon cycle log

Science Starter: 1. What does the Law of Conservation of Matter tell us?2. What are at least 2 processes that illustrate the Law of

Conservation of Matter. 3. List two ways that carbon dioxide enters the

atmosphere. 4. List two organisms that contain carbon as a solid.

The Nitrogen Cycle

The Nitrogen Cycle – the series of processes which shows how nitrogen is recycled throughout the environment

Why is the nitrogen important?

Nitrogen is important because it makes amino acids

and nucleic acids.

protein

Scholarly Word Alert!DNA – deoxyribonucleic acid

Why is nitrogen important?

80% of the Earth’s atmosphere is nitrogen gas (N2), but plants and animals can’t use it!

The Nitrogen Cycle

Nitrogen gas (N2) must be broken down by lightning, fire, or bacteria before plants & animals can use it.

The Nitrogen Cycle

There are four forms of Nitrogen.1. Nitrogen gas (N2)2. Nitrite (NO2

-) 3. Nitrate (NO3

- )4. Ammonium ion (NH4

+ ) Plants and animals can only take in

nitrate (NO3- ) and ammonia (NH4+ ).

Nitrification Nitrogen

Fixation –when bacteria “fix” nitrogen from the air so the plants can use it

Table Group Points!

What forms of nitrogen can plants and animals use?Nitrate and Ammonia

How does nitrogen fixation occur?Bacteria, that

live on the roots of some plants, change nitrogen into ammonia, a form of nitrogen plants can use.

Denitrification

Denitrification – is when bacteria recycle nitrogen back to the atmosphere.

Ammonia in the soil is converted back into nitrogen gas (N2)

The Nitrogen Cycle Animals

(including humans) get nitrogen by eating plants.

All nitrogen obtained by animals can be traced back to the eating of plants.

Ammonification Ammonificatio

n - When plants and animals die, their bodies decompose and release ammonia back into the soil for plants to use.

Table Group Point!

What else happens when living things decompose? Hint: Think of another cycle that we know.

Human Impact Burning fossil fuels

and wood contributes to a large amount of nitric oxide in the atmosphere. 

Nitric oxide can combine with oxygen gas to form acid rain.  The acid can damage trees and kill fish. 

Table Group Point!

Acid rain speeds up another process that we learned about that is part of another cycle. What process does acid rain speed up?

Nitrogen Cycle Skill Builder

Understand? Take a stand!• I will read a question.• When you know the answer, stand

up!• ONLY STAND UP IF YOU HAVE AN

ANSWER READY.• I will call on students who are

standing. If you answer correctly, you will get a point. If you answer incorrectly, sit down.

Where do animals get nitrogen?

By eating plants which have nitrogen!

So where do the plants get nitrogen?

From the soil!

What 3 ways can nitrogen gas be breakdown so that plants can use it?

By lightning, bacteria and fire!

What is it called when bacteria recycle nitrogen back into the atmosphere?

Denitrification!

EXIT TICKET

Choose and answer 3 of the questions on the following slide. Be sure to write the QUESTION and the answer.

1. Explain two ways that nitrogen gas in the atmosphere is changed into nitrogen compounds that plants can use.

2. Compare and contrast the carbon cycle and the nitrogen cycle. List at least one way that they are similar AND one way that they are different.

3. List at least two ways in which nitrogen can get into the ground.

4. Does the nitrogen cycle ever end? Explain your answer in at least two complete sentences.

5. Without bacteria, what would happen to the nitrogen cycle? Explain why.