Chapter 23: Pathways of Elements Flashcards
Where are the four stores of water in the water cycle (in decreasing order)?
Oceans, sedimentary rocks, runoff/ground water, and atmospheric vapor
Where is most of the water in the water cycle?
The oceans
What type of reaction is photosynthesis?
Reduction (energy-requiring)
What does photosynthesis do in the carbon cycle?
Reduces carbon dioxide (CO2) to organic carbon (CH2O)
What type of reaction is respiration in the carbon cycle?
Aerobic, energy-releasing oxidation
What does respiration do in the carbon cycle?
Oxidizes organic carbon (CH2O) into carbon dioxide (CO2)
In what form is carbon lost to the atmosphere?
Methane (CH4)
What is the process of transformation between organic nitrogen and ammonium (NH4+)?
Ammonification
What is the process of oxidizing ammonium (NH4+) to nitrite (NO2-) called?
Nitrification
What is the process of oxidizing nitrite (NO2-) to nitrate (NO3-) called?
Nitrification
What is the process of reducing nitrate (NO3-) to nitrite (NO2-) called?
Dentrification
What is the series of forms nitrogen takes when reducing nitrate (NO3-) to become ammonium (NH4+)?
NO3- ➡ NO2- ➡️ NO ➡️ N2O ➡️ N2 ➡️ NH4+
What is the process of transforming N2 (molecular nitrogen) into NH4+ (ammonium) called?
Nitrogen fixation
What form does most nitrogen take that is inaccessible to organisms?
Nitrogen gas (N2)
What two things cause nitrogen fixation?
Lightning and certain bacteria
