1. Cycles of Matter

2. Recap: Matter is made up of tiny particles called atoms.
Living organisms consist mainly of:
Hydrogen, oxygen, carbon, and nitrogen
Life’s most important compounds include:
Water, carbohydrates, lipids, nucleic acids, and proteins

3. Biogeochemical Cycles
Cycles of matter include:
Biological processes
Geological processes
Chemical processes
AND human activity
can play an important role
Energy flows through an ecosystem whereas matter is continuously recycled

4. Cycles of Matter
The important cycles of matter in an ecosystem include
water cycle
carbon cycle
nitrogen cycle
phosphorus cycle

5. The Water Cycle Water is essential for life
Water continually moves from the Earth’s surface to the atmosphere and back in a process known as the water cycle.

8. Nutrient Cycles
Nutrients- chemical substances that organisms need to sustain life

9. The Carbon Cycle
Carbon is an element that is found in all living things.
Carbon is cycled through the processes of photosynthesis and respiration
Plants take the carbon dioxide and use it to make glucose during photosynthesis
During respiration, mitochondria use oxygen to break down glucose for energy.

11. The Nitrogen Cycle
Nitrogen is an element that has to be “fixed” before most organisms are able to use it.
The changing of free nitrogen gas to a useable form is called nitrogen fixation
Most nitrogen fixation is performed by bacteria that live in bumps called nodules on the roots of certain plants.
These plants are known as legumes and include clover, beans, peas, alfalfa, and peanuts.
Nitrogen returns to the environment through animal wastes which are broken down by decomposers.

12. Roles of Bacteria in the Nitrogen Cycle
Nitrogen-fixing bacteria that live in nodules on the roots of plants change nitrogen gas into nitrogen compounds.
Bacteria that are decomposers recycle nitrogen compounds in the soil
Other bacteria release free nitrogen to the air.
What would the role of animals be?
Consume nitrogen when eating plants, or organisms that eat plants
Return nitrogen to the soil through wastes

14. Phosphorus Cycle
Phosphorus is essential to living things because it plays a vital role in vital molecules such as DNA and RNA.
It is NOT abundant in the atmosphere unlike carbon oxygen and nitrogen