Nutrition and Energy Flow Chapter 2, section 2
How organisms Obtain Energy • Energy drives all events • Important characteristic of a species niche is how energy is obtained • Ultimate source of energy is the sun
Autotrophs • The Producers • Plant use photosynthesis to manufacture their own food. • Autotrophs – organisms that use energy from the sun or stored in chemical compounds to manufacture their own nutrients.
Heterotrophs • The Consumers • Heterotrophs – organisms that cannot make their own food and must feed on other organisms. • Scavengers – organism that do not kill for food but eat animals that have already died. • Herbivore • Carnivore • Omnivore
Herbivore • Herbivore – eat plants
Carnivore • Carnivore – eats animals
Omnivore • Omnivore – eats both plants and animals
Decomposer • Decomposers – Breakdown complex compounds of dead decaying plants and animals.
Food Chains • Food Chain – simple model that scientists use to show how matter and energy move through an ecosystem. • Consists of 3 links or steps • Trophic level represent link in the chain • Energy is lost at each step as heat • Like energy, nutrients are also moved through the organisms at the different levels • These nutrients are being recycled
The Water Cycle • Water begins its cycle through the ecosystem when plants absorb water through their roots • As water moves through the ecosystem, plants and animals lose it through respiration • Decomposition also releases water back into the ecosystem
The Carbon Cycle • Carbon is found as Co2 in the air and oceans • The first step of this cycle happens when the producers take it in • This carbon is moved on when consumers eat these producers • The carbon is then put back into the environment by respiration and decay
The Nitrogen Cycle • Atmospheric nitrogen is the most occurring gas in the air but organisms can't use this form of nitrogen • Lightning or some types of bacteria can turn atmospheric nitrogen into usable compounds • Plants use these compounds and turn them into nitrates • Consumers eat the plants and turn the nitrates into protein • The nitrogen returns to the environment by death and decay
The Cycling of Phosphorus • Phosphorus cycles in two different ways • Plants get the phosphorus from the soil and animals get the phosphorus by eating the plants • The phosphorus is returned when the animal dies and decomposes • The second way is started when its washed into the sea and becomes incorporated into rock • Millions of years later, the phosphorus is driven from the rocks becoming exposed again