The ways in which an element—or compound such as water—moves between its various living and nonliving forms and locations in the biosphere is called a biogeochemical cycle. …

Jun 9, 2016 · Bacteria play a key role in the nitrogen cycle. Nitrogen enters the living world by way of bacteria and other single-celled prokaryotes, which convert atmospheric nitrogen— N 2 …

Biogeochemical cycles are nature's way of recycling essential elements for life, like water, carbon, nitrogen, and phosphorus. These cycles circulate these molecules through ecosystems and …

Learn how carbon moves through Earth's ecosystems and how human activities are altering the carbon cycle.

Water found at the Earth's surface can cycle rapidly, but much of Earth's water lies in ice, oceans, and underground reservoirs; this water cycles slowly. The water cycle is complex and involves …

Natural cycling of phosphorus The phosphorus cycle is slow compared to other biogeochemical cycles such as the water, carbon, and nitrogen cycles. 1 In nature, phosphorus is found mostly …

Apply your understanding of biogeochemical cycles in this set of free practice questions aligned to AP standards.

Not every nutrient will go through these cycles in the same path. People often think that biogeochemical cycles are linear, and that each atom or molecule goes through the cycle step …

Overview and steps of the citric acid cycle, also known as the Krebs cycle or tricarboxylic acid (TCA) cycle.

Carbon atoms end up in you, and in other life forms, thanks to the second stage of photosynthesis, known as the Calvin cycle (or the light-independent reactions).