All living things need energy to survive What is the source of that energy? The Sun!
Producers (or primary producers) use the sun’s energy to make food This process is called photosynthesis energy from light is absorbed by proteins that contain green chlorophyll pigments
Organisms that make their own food are called Autotrophs “Auto”=self “Troph”=feed Plants Some Bacteria Moss Algae
Consumers cannot make their own food. They must eat other organisms to get energy. Breaking down food to release the stored energy for use is called cellular respiration
Organisms that use cellular respiration to get energy are called Heterotrophs. “Hetero”=other “Troph”=feed Animals Some Bacteria Fungi
Food Chains and Food Webs Primary consumers (herbivores) feed directly on producers Herbivores are organisms that eat plants or algae ex. Moose, cattle, grasshoppers, rabbits Secondary consumers feed on primary consumers Tertiary consumers feed on secondary consumers
High-level consumers are usually carnivores Carnivores are organisms that eat mainly meat ex. lions, polar bears, sharks Omnivores are organisms that eat both plants and meat (producers and consumers) ex. humans, raccoons, most bears, most primates
Food chains show the relationship of feeding and energy transfer in organisms of an ecosystem Many food chains become connected in a complex relationships called a food web
Each step in a food chain is known as a trophic level Energy moves up the trophic levels
Detritivores eat dead organisms and waste ex. earthworms, maggots Decomposers consume and break down dead organisms or waste matter into simple substances. Send nutrients back into the soil ex. mold, fungi
Photosynthesis The process of photosynthesis is a chemical reaction It is the most important chemical reaction on our planet!
The process of changing light energy to chemical energy Energy stored as sugar Occurs in plants and some algae Takes place in the chloroplasts, using chlorophyll, the green pigment in plantschloroplasts chlorophyll
Plants capture light energy and use that energy to make glucose (sugars) Sunlight provides the energy needed by chlorophyll to change molecules of carbon dioxide and water into glucose Oxygen is also released in this reaction
Why is it important to us? We cannot make our own food (glucose, energy), we must get our food from plants. Plants are the first step in the food chain. The oxygen released during photosynthesis is necessary for all living things.
Cellular Respiration The release of chemical energy for use by cells. The breakdown of glucose molecules to release energy Once the energy that was in sunlight is changed into chemical energy by photosynthesis, an organism has to transform the chemical energy into a form that can be used by the organism.photosynthesis
Energy Pyramid Species in the highest trophic levels have less energy available to them than species near the bottom This often results on their populations being much smaller than species lower in the food chain (number of predators<herbivores) 100 0