Organisms, Energy & Ecosystems

Characteristics of Organisms

1) Take in and convert materials and energy from the environment; release wastes. 2) Have a high degree of chemical organization compared to non living objects. 3) Have complex structural organization that is responsible for their appearance and activities. 4) Contain coded instructions (such as DNA) for maintaining their organization and activities. 5) Sense and react to changes in their environment. 6) Grow and develop during some part of their lives. 7) Reproduce others like themselves. 8) Communicate with similar organisms. 9) Move under their own power.

Photoautotrophs

An organism that derives energy from light and forms its own organic compounds (food) from abiotic carbon sources.

Chemical Work

Constructing and breaking down large, complex molecules [such as proteins & nucleic acids]. 2) AND it can be considered organizing these molecules into the larger, structural components of cells, such as in muscle and skin.

Chemical Energy

Energy stored in the structures of molecules. Example: Organisms store energy in the organic molecules from which the organisms are made.

Mechanical Work

Includes movement: such as muscle contractions that enable you to kick a ball.

Transport Work

Involves the movement and concentration of raw materials [nutrients] needed to make complex molecules and to increase cellular organization during growth.

Heterotrophs

Obtain energy and nutrients from other organisms, either living or dead. Example: Animals, fungi (mushrooms and molds) and most bacteria.

Autotrophs

Organisms that obtain their energy and nutrients from nonliving sources: sun, minerals and the air. Example: plants, certain bacteria, and other organisms that capture energy from the sun or from chemicals such as Hydrogen sulfide. Autotrophs use that energy to synthesize organic compounds from inorganic materials absorbed from their surroundings. Many capture energy through photosynthesis.

Energy

The capacity to do work or create change.

Free Energy

The portion of [ sometimes chemical] energy that is available to do work. Example: The energy plants use for growing and producing food. The energy you use for exercise and thinking. Other autorophs, all of which are bacteria, can obtain free energy from inorganic chemicals in the environment.

Photosynthesis

The process by which cells use light energy to make organic compounds from inorganic materials. Some of the energy captured in photosynthesis is stored as chemical energy in organic compounds, which later serve as the source of free energy for cellular work.