SOURCES OF ENERGY A. Every living thing needs energy to make proteins and to transport substances into and out of the cell. 1. Trophic Levels example a. Grass uses the Sun b. Zebras eat the Grass c. Lions eat the zebras

B. The process by which cell captures energy in sunlight and uses it to make food is called Photosynthesis. 1. Photo means “light” Synthesis means “putting together” 3. The majority of Photosynthesis takes place in the leaves of plants.

C. The SUN provides most of the Energy used by living things. 1. An organism that makes it’s own food is called an autotroph. 2. An organism that CANNOT make its own food is called a heterotroph. a. Obtain food by eating other organisms. b. Fungi absorb their food from other organisms.

D. Photosynthesis is a Two Stage process that takes place in the Chloroplasts. 1. Stage 1: Capturing the Sun’s Energy a. The green pigment, Chlorophyll, is a colored chemical that absorbs Sunlight. b. Inside Chloroplasts, H 2 O and CO 2 undergo a series of chemical reactions that are powered by the Sun’s energy that is absorbed by chlorophyll (1 st stage of photosynthesis)

2. Stage 2: Using Energy to Make Food a. Cells use the absorbed light energy to produce___________. * the raw materials are H 2 O (from the roots) and CO 2 (from the air) * CO2 enters the leaves through small openings called Stomata. b. Stomata open and close to control the movement of CO 2, O 2, and H 2 O vapor into and out of the leaf.

c. glucose and oxygen are the products d. some glucose used by the plant cell, some is stored as carbohydrates. e. oxygen leaves the leaf through stomata.

E. Photosynthesis Equation: Light Energy 6CO 2 + H 2 O C 6 H 12 O 6 + 6O 12