Biological processes must adhere to the first law of thermodynamics which states that energy is neither created nor destroyed, but can be transferred from one system to another and be transformed.

a. Describe the flow of energy at the community and cellular level.

b. Describe where energy comes from to sustain life within a community ecosystem and explain how energy can be transferred from one species to another.

c. Discuss energy sources at the cellular level and the processes and molecules that a cell uses in transferring, storing and using energy.

d. Explain why oxygen plays an important role in these processes for some cell types, but not for others.

e. Discuss the types of processes for which cells use energy.