Gas exchange

What is the problem? We need atp

Why must organisms constantly Synthesize atp?

1. Most cells utilize ATP as their primary source of energy

2. the high energy phosphate bond is very unstable

3. body does not store energy as atp

4. Cells must constantly synthesize

   Primary biomolecule utillized by cells to synthesize ATP : glucose

   The primary reaction that occurs at the cellular level to extract atp from glucose: cellular respiration

Cellular respiration: the processes by which organic compoundsare oxidized to harvest energy; primary bi-product is carbon dioxide

What is needed?

1. A mechanism to extract oxygen from the environment and bring into the body

2. Amechanism to remove carbon dioxide from the body and deliver it to the environment

This involves 2 Compounds

1. Respiratory exchange surface - place where oxygen goes in and carbon dioxide goes out

2. Respiratory medium - the stuff carrying oxygen in and carbon dioxide out

Organismal respiration: the exchange of oxygen and carbon dioxide between the whole organism and the environment

Respiratory exchange surface: in all animals: structure that facilitates the movement of oxygen into the organism and carbon dioxide out

Simpler organisms: phyla: porifera and nideria:The plasma membranes of individual cells are respiratory exchange surfaces

More complex animals: develop complex respiratory exchange surface that serves to exchange oxygen for carbon dioxide between whole organism and environment

Respiratory medium: that component of the environment that carries oxygen to the animal and carries carbon dioxide away from the animal

The respiratory medium is the component from the external environment and determines the respiratory exchange surface of animals