Energy and Ecology

All living things need energy For work –Chemical reactions –Transport materials into/out of cells –Mechanical (muscle contraction) This energy is found in / stored in molecules

Organisms also need nutrients Carbon and other essential elements (nitrogen and phosphate for example) to build their own biomolecules How do they get this energy and these nutrients? Other organisms Heterotrophs Nonliving sources Autotrophs Photosynthetic  use energy in light to make these molecules Chemosynthetic  use energy from inorganic chemicals to make these molecules

Fig. 1-2 Ecosystem Producers (such as plants) Sunlight Cycling of chemical nutrients Chemical energy Consumers (such as animals) Heat

What happens to the organisms after they die? Decomposers  primarily fungi and bacteria

Decomposers (detrivores) are not typically included in a food web. What are these ?

Pyramid of Energy only about 10% of energy in a trophic level will become energy found in the next level

Ecosystem What is it? How does it fit with all the other levels of organization of living things?

Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Nucleus Nerve Spinal cord Cell Nerve cell Tissue Nervous tissue Organ Brain Organelle Nucleus Molecule DNA Atom Organism Brown pelican Organ system Nervous system Brain Biosphere

Fig. 1-1a Biosphere Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican

Fig. 1-1b Nucleus Nerve Spinal cord Cell Nerve cell Tissue Nervous tissue Organ Brain Organelle Nucleus Molecule DNA Atom Organism Brown pelican Organ system Nervous system Brain

What do you think will happen to a population of organisms if given unlimited resources? What if there is a limited amount of food? nutrients? Available shelter?