AP Environmental Science Module Three Lesson Three Overview

Biogeochemical Cycles

picture of mushroom with text that reads Biogeochemical cycles

The earth is a closed system for matter. Nutrient cycles, or biogeochemical cycles, involve natural processes that recycle nutrients in various chemical forms. Several important cycles will be examined in this lesson.

Objectives and Checklist

By the end of this lesson, you will be able to:

Explain the steps of each of the Natural Biogeochemical Cycles (Carbon, nitrogen, phosphorus, sulfur, water, conservation of matter)

Key Terms

assimilation: absorbing nitrates and turning them into amino acids, proteins, DNA
nitrogen fixation: conversion of atmospheric nitrogen gas into NH₃ and NH₄ by lightning, bacteria, and cyanobacteria
denitrification: anaerobic bacteria convert ammonia into nitrogen gas and nitrous oxide gas
nitrification: ammonia is converted by bacteria to nitrates and then to nitrates
ammonification: decomposers turn nitrogen compounds into ammonia
weathering: the breaking down of soil, rocks, and minerals
guano: feces of seabirds and bats
evaporation: the process by which water turns from the liquid phase to the gaseous phase
transpiration: the process of water leaving a plant's leave through stomata
infiltration: downward movement of water into the soil
absolute humidity: amount of water vapor in air: gH₂0/ kg air
relative humidity: percentage of maximum amount of water vapor that air could hold at the temperature
percolation: passage of a liquid through the spaces of a porous material such as soil in the aquifer
dew point: temperature at which condensation occurs

AP Environmental Science Module Three Lesson Three Overview

Objectives and Checklist

Key Terms

Reference List

Resources

Image Citations

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