https://www.khanacademy.org/science/biology/ecology/biogeochemical-cycles/v/biogeochemical-cycles 2024-05-06T19:22:43.24334365Z Biogeochemical cycles overview 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 the entire biosphere. From the water cycle to the carbon cycle, these processes ensure the constant reuse of matter, while energy flows through the ecosystem. Sal Khan video https://cdn.kastatic.org/googleusercontent/RkZfK_GfyQENMLzn91OXdJD-6fcWtW4iD5D2jYN8t2sSGSm9SmuUbQpyotrMYkzgCLJGmJfw0BnooTWMjSSGNWw Biogeochemical cycles overview 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 the entire biosphere. From the water cycle to the carbon cycle, these processes ensure the constant reuse of matter, while energy flows through the ecosystem. https://cdn.kastatic.org/ka-youtube-converted/ccWUDlKC3dE.mp4/ccWUDlKC3dE.mp4 475 Biogeochemical cycles & water resources https://www.khanacademy.org/science/biology/ecology/biogeochemical-cycles/a/introduction-to-biogeochemical-cycles 2025-06-30T13:17:39.587845569Z Intro to biogeochemical cycles Get an overview of how atoms are recycled through Earth's ecosystems via biogeochemical cycles. article https://www.khanacademy.org/science/ap-biology/ecology-ap/energy-flow-through-ecosystems/v/flow-of-energy-and-matter-through-ecosystems 2024-05-08T17:59:40.799210289Z Flow of energy and matter through ecosystems Energy flows and matter recycles in ecosystems, with the Sun as the primary energy source. Plants, as primary producers, convert sunlight into energy-storing biomolecules. Consumers, like animals, obtain energy by eating plants or other animals. Decomposers break down dead organisms, recycling matter and nutrients. Energy is conserved but often released as heat, while matter constantly cycles through the ecosystem. Sal Khan video https://cdn.kastatic.org/googleusercontent/wi_ooqQppefn_o67MB2y0Pgax1p5vKDVr9mj7_kuG6IK5tFwTUetpM1OigZ75_XEnzZhusHhr41EC3CBqHcgm3LPlA Flow of energy and matter through ecosystems Energy flows and matter recycles in ecosystems, with the Sun as the primary energy source. Plants, as primary producers, convert sunlight into energy-storing biomolecules. Consumers, like animals, obtain energy by eating plants or other animals. Decomposers break down dead organisms, recycling matter and nutrients. Energy is conserved but often released as heat, while matter constantly cycles through the ecosystem. https://cdn.kastatic.org/ka-youtube-converted/TitrRpMUt0I.mp4/TitrRpMUt0I.mp4 626 Biogeochemical cycles & water resources https://www.khanacademy.org/science/middle-school-earth-and-space-science/x87d03b443efbea0a:weather-and-climate/x87d03b443efbea0a:the-water-cycle/a/the-water-cycle-ms 2022-04-18T22:23:46.314561906Z The water cycle Review your understanding of the water cycle in this free article aligned to NGSS standards. article https://www.khanacademy.org/science/biology/ecology/biogeochemical-cycles/v/nitrogen-cycle 2024-05-06T19:22:43.24334365Z The nitrogen cycle The nitrogen cycle is a crucial process that converts atmospheric nitrogen into a form that plants and other organisms can use. This process, known as nitrogen fixation, is primarily carried out by bacteria. Nitrogen is essential for life, forming a key component in amino acids, ATP, and DNA. The cycle also includes the return of nitrogen to the atmosphere through decomposition. Sal Khan video https://cdn.kastatic.org/googleusercontent/gQTO9JBwADmey2m_RcYCR_nTXRtFSeKzD8OmiRJn46LlNov4Q7sqsF2imvMCMS8i7OccArqSUWSxktBugc1seihb0g The nitrogen cycle The nitrogen cycle is a crucial process that converts atmospheric nitrogen into a form that plants and other organisms can use. This process, known as nitrogen fixation, is primarily carried out by bacteria. Nitrogen is essential for life, forming a key component in amino acids, ATP, and DNA. The cycle also includes the return of nitrogen to the atmosphere through decomposition. https://cdn.kastatic.org/ka-youtube-converted/DsCMYyQ0NWU.mp4/DsCMYyQ0NWU.mp4 345 Biogeochemical cycles & water resources https://www.khanacademy.org/science/biology/ecology/biogeochemical-cycles/a/the-nitrogen-cycle 2024-05-29T17:16:29.06533157Z The nitrogen cycle The key role of microbes in nitrogen fixation. How overuse of nitrogen-containing fertilizers can cause algal blooms. article