1. Cycling of Organic and Inorganic Matter
(Sec 4.1 pg 83-85)

2. Since its formation, Earth has contained all of the matter it will ever will.
Energy is different; it keeps being added to the Earth’s system from the Sun.

3. Matter needs to be re-used.
The process of re-using matter is known as cycling.
All life on Earth depends on the cycling of matter, between abiotic and biotic components of the environment.

4. Two types of matter cycle through nature (Fig 1 p.83):
Organic matter = this is matter that contains more carbon and hydrogen by mass than other elements (although other elements may be present).

5. Two types of matter cycle through nature (Fig 1 p.83):
Inorganic matter = this matter is not of biological origin, may or may not contain C, and is usually of mineral origin. Carbon dioxide is considered inorganic (contains C but not H).

6. Table 1 p.83 summarizes some common organic and inorganic compounds.

7. While many processes are involved in the cycling of compounds / matter, the two most important are:
Photosynthesis, it is when a plant uses sunlight to turn carbon dioxide (CO2) and water (H2O) into sugar (food, C12H22O12) and oxygen (O2). It occurs in the chloroplasts of green plants.

8. While many processes are involved in the cycling of compounds / matter, the two most important are:
Cellular respiration is when consumer cells do the exact opposite, and convert sugar and oxygen into water and carbon dioxide.

9. Check out Priestley’s famous experiment described on p. 84
Check out Priestley’s famous experiment described on p.84. It highlights the co- dependence of animals and plants (in a closed system, one needs the other to survive).

10. Classwork
pg , 8, 10