 At the core of every organism’s interaction with the environment is its need for energy to power life’s processes.

 Living systems operate by _______________________________________.  Organisms need energy for _________, _____________ and ____________________.  If there is no energy, there are no life functions!  Yet no organism can create energy – organisms can only use energy from other sources.

 For most life on Earth, ______________ is the ultimate energy source.  For some organisms, _________________________________stored in inorganic compounds serves as the ultimate energy source.

 Only a few organisms such as algae, some bacteria and plants can capture energy from sunlight or chemicals and convert it into forms that living cells can use.  These organisms are called ____________.  Autotrophs

 Autotrophs also store energy in forms that make it available to other organisms to eat them.  That’s why autotrophs are also called _____________________________________.  Primary producers, are the first producers of energy-rich compounds that are later used by other organisms.

 The best known and most common primary producers harness solar energy through the process of photosynthesis.  Photosynthesis:

 Without photosynthetic producers, the air would not contain enough ________________ for you to breathe.

 Biologists discovered thriving ecosystems around volcanic vents in total darkness on the deep ocean floor.  There was no light for photosynthesis, so who or what were the primary producers?  These organisms were using ______________________, in which chemical energy is used to produces carbohydrates.

 Other organisms that cannot directly harness energy from the environment are known as ____________________________.  A heterotroph must:

 Heterotrophs are also called _________________ – organisms that rely on other organisms for energy and nutrients are called consumers.

 Consumers are classified by the ways in which they acquire energy and nutrients.

 Carnivores:  Herbivores:  Omnivores:

 Scavengers:  Decomposers:  Detritivores:

 Categories will often overlap.  Hyenas are described as carnivores, but they will scavenge if they get a chance.  Many aquatic animals eat a mixture of algae, bits of animals carcasses, and detritus particles.