1. What elements are most important for life? The Earth’s elements essential for living things are called nutrients. The six most important are: C H N O P S

2. What are Chemical Cycles? Over time, these elements (nutrients) are transported through the living and nonliving parts of our planet in sets of processes called chemical cycles.

3. Chemical Cycles Examples of these cycles include the: 1.oxygen cycle, 2.carbon cycle, 3.nitrogen cycle, and 4.phosphorus cycle. Even before life appeared on Earth millions of years ago, elements were recycled!

4. What are ecosystems? An ecosystem consists of a group of living things and their physical surroundings. The Sun is the main energy source for ecosystems.

5. Living parts of Ecosystems: A producer is a living thing, like a plant, that can take the Sun’s energy and store it as food. A consumer must feed on other living things to get food and energy. – An herbivore is a consumer that eats only plants. – A carnivore is a consumer that eats only animals. – A consumer that eats both plants and animals is called an omnivore.

6. A decomposer is a living thing that consumes waste and dead organisms to get energy. Decompose means “to break down”. Living parts of Ecosystems:

7. How do we connect living parts of an ecosystem? A food chain shows how each member of an ecosystem gets its food. A simple food chain links a producer, an herbivore, and one or more carnivores. Which is the herbivore?

8. What is photosynthesis: Photosynthesis is the process in which CO 2 and H 2 O are converted to sugars and oxygen. Solar energy is converted to chemical energy!

9. What is Respiration: Respiration is the process where sugars and oxygen are converted into CO 2 and H 2 O. Energy is released!

10. These are opposite processes!!!

11. The Carbon Cycle:

12. Four “Spheres” of the Earth Atmosphere The gases that surround us! (Air!) Biosphere The living things on Earth! (Life!) Hydrosphere All forms of H 2 O on earth! (Water!) Geosphere Earth’s soil, crust, mantle, etc. (Land!)

13. The Water Cycle Living things need water and sunlight. In nature, water recycles so it can be used in many ecosystems. Water supply depends on the water cycle.

14. Like water, O 2 is essential for living things. Plants release O 2 into the atmosphere during photosynthesis. During respiration, plants or animals use oxygen to store energy. The Oxygen (O 2 ) Cycle

15. Nitrogen is necessary for living things to make amino acids, the building blocks of all proteins. Approximately 78 percent of Earth’s atmosphere is nitrogen gas (N 2 ). The Nitrogen (N 2 ) Cycle

16. Phosphorus allows cells to reproduce, undergo reactions, and build structures. Plants absorb phosphorus from minerals in the soil through their roots. Animals obtain phosphorus by eating plants. The Phosphorus (P) Cycle

18. Pollution in ecosystems Human activities create toxic pollutants (toxins). High concentrations of toxins impact living things.

19. Pollution in ecosystems Mercury from power plants falls to Earth with rain and ends up in lakes and oceans. As toxic mercury is concentrated up the food chain, it can accumulate to dangerous levels if ingested by humans.

20. All Geochemical Cycles interconnect! Cycles do not have beginning or ending points; elements (nutrients) and energy are moving constantly. All organisms, they release heat energy as they metabolize nutrients.