ENERGY FLOW • All Life on Earth needs energy for cell processes. • For most life on Earth, sunlight is the ultimate energy source. • Organisms get energy by using light or chemical energy to make food or by eating other organisms
PRODUCERS • Producerschange the energy available in their environment into food energy. • They make their own food (autotrophs) • Plants, algae, and some microorganisms use a chemical process called photosynthesis to change light energy into chemical energy (Glucose) • This process adds oxygen to the atmosphere and removes carbon dioxide.
Producers That Use Sunlight phytoplankton Plants & Trees Algal colony cyanobacteria
Life Without Light • Biologists have discovered thriving ecosystems around volcanic vents in total darkness on the deep ocean floor. • Deep-sea ecosystems depend on primary producers that harness chemical energy from inorganic molecules such as hydrogen sulfide. • The use of chemical energy to produce carbohydrates is called chemosynthesis. giant tube worms live in symbiosis with the chemosynthetic bacteria
Consumers • Consumers- organisms that cannot make their own • food and get their energy from eating other organisms.(heterotrophs) • Consumers use the chemical process of cellular respiration to break down food in the presence of oxygen to produce energy.
Types of Consumers • Consumers are classified by the ways in which they acquire energy and nutrients. • Herbivores-obtain energy and nutrients by eating plant leaves, roots, seeds, or fruits.
Types of Consumers Carnivores-kill and eat other consumers
Types of Consumers Omnivores-consume a variety of different foods that usually include both plants and animals. Humans, bears, and pigs are omnivores.
Types of Consumers Scavangers-animals that consume the carcasses of other animals that have been killed by predators or have died of other causes.
Types of Consumers • Decomposers-such as bacteria and fungi, feed by chemically breaking down organic matter. • The decay caused by decomposers is part of the process that produces detritus—small pieces of dead and decaying plant and animal remains. • Decomposers that live on, and in, detritus particles are called Detrivores. • They feed on detritus particles, often chewing or grinding them into smaller pieces. Ex: giant earthworms
Food Chains • Each time one organism eats another organism, a transfer of energy occurs • Food chain-models how energy flows in an ecosystem through feeding relationships. • Food chains can vary in length. An example from the Everglades is shown.
Food Webs Food web- links all of the food chains in an ecosystem together. • It shows many feeding relationships that are possible in an ecosystem An example of a food web in the Everglades is shown.
Trophic Levels and Energy Pyramids Each step in a food chain or food web is called a trophic level. Primary producers always make up the first trophic level. Various consumers occupy every other level Energy pyramids- show the amount of food energy available at each trophic level
Trophic Levels and Energy Pyramids Energy pyramids- show the amount of food energy available at each trophic level Each time energy is transferred from one organism to another, lost and less energy is available at the next trophic level.
Trophic Levels and Energy Pyramids Energy is lost: as heat through cellular respiration. this energy is used to carry out functions of living things such as producing new cells, regulation of body temperature, and moving around
Trophic Levels and Energy Pyramids The remaining 10% of the energy becomes part of the organism’s body and is stored in its molecules. This 10% is available to the next trophic level when one organism consumes another organism