Notes from Biology course.


Organic molecule:

  • A molecule of the kind normally found in living systems
  • Often composed of carbon atoms in rings or chains, to which are attached other atoms like H, O, and N

PRODUCER: An autotrophic organism that produces organic compounds from CO2 using light energy (process of photosynthesis) or by oxidizing inorganic chemicals. Producers use the sugar to grow

AUTOTROPH → mainly plants, algae and some bacteria.

  • An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms
  • Uses energy from the sun or oxidation of inorganic substances to make organic molecules from inorganic ones


  • Feed on producers and other consumers
  • Animals use sugar to move ← Convert chemical energy to kinetic energy


  • An organism that obtains organic food molecules by eating other organisms or substances derived from them

• AUTOTROPHS = Producers • HETEROTROPHS = Consumers – Includes detritivores (class of organisms that feeds on detritus or organic waste)

For every energy transfer: – Some energy converted to thermal energy Dissipates as heat • Energy enters the ecosystem from the SUN and exits as HEAT

  • Metabolism • HOMEOSTASIS – The steady-state physiological condition of the body. • Biological processes self-regulate by a mechanism called FEEDBACK Blood clot – Blood vessel damaged, platelets aggregate at the site – Platelets release chemicals that attract more platelets

SUMMARY: • All energy ENTERS the ecosystem from the sun • All energy eventually LEAVES the ecosystem as heat • For every energy transfer or transformation, some energy is lost as heat All energy comes from the sun Animals must eat organic molecules made by producers Animals are heterotrophs/consumers: they obtain organic molecules by eating other organisms or substances derived from them Animals breaking down sugars to use for energy is an example of CATABOLISM. Plants capture solar energy and use it to build complex organic molecules Plants are autotrophs/producers: they get energy from the sun which they use to make their own organic molecules Photosynthesis is an example of ANABOLISM.

Growth and reproduction Reproduction