Key Terms

ATP
Adenosine triphosphate is the energy-carrying molecule found in the cells of all living things.  ATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes.

Bicarbonate
Bicarbonate is an acid carbonate ion, HCO₃^-

Chlorophyll a
Chlorophyll a is present in all organisms capable of oxygenic photosynthesis.  It is a member of the most important classes of pigments involved in photosynthesis.

Cyanobacteria
Cyanobacteria are single celled, prokaryotic, microscopic organisms.  Cyanobacteria are photosynthetic algae.  They release oxygen and uptake carbon dioxide.  Cyanobacteria contain pigments.  The prevalence of one particular pigment will determine the color of the algae.  They can be black, green, violet, blue-green, yellow, brown, and red.  Cyanobacteria are among the oldest forms of organisms found on Earth.  They are extremely common today and are found in fresh, brackish and salt water.

Greenhouse effect
The greenhouse effect is a naturally occurring process that aids in heating the Earth's surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, water vapor, and methane, are able to change the energy balance of the planet by being able to absorb longwave radiation from the Earth's surface. Without the greenhouse effect, life on this planet would probably not exist as the average temperature of the Earth would be a chilly ^-18 degrees Celsius, rather than the present 15 degrees Celsius.

Greenhouse gases
Gases in the Earth’s lower atmosphere (troposphere) that causes the greenhouse effect.  Examples are water vapor, carbon dioxide, chlorofluorocarbons, ozone, methane, and nitrous oxide.

Photosynthesis
A complex food making process that takes place in cells of green plants. Radiant energy from the sun is used to combine carbon dioxide (CO₂ ) and water (H₂0) to produce oxygen (0₂) and carbohydrates (such as glucose, C₆H₁₂O₆) and other nutrient molecules.

Phycobilins
Phycobilins are accessory pigments that trap energy from the sun and pass it onto chlorophyll a.

Pigments
Pigments are any group of compounds that are intensely colored and are used to color other materials.

ppm
Number of parts of a chemical found in one million parts of a particular gas, liquid, or solid.

Prokaryotes
Prokaryotes are cellular organisms that do not have a distinct nucleus.

NADPH
NADPH is a molecule created during the process of photosynthesis.  It is created by reduction, gaining an electron.  NADPH forms a positive ion.

Q: Has the Earth really warmed?

A:  The globally averaged temperature of the air at the Earth’s surface has warmed between 0.3 and 0.6 °C (about 0.5 and 1.0 °F) since the late nineteenth century.  The four warmest years on record since 1860 have all occurred since 1990.