Presentation on theme: "Ecosystems: Cycling of Matter SC STANDARD B-6.4: EXEMPLIFY THE ROLE OF ORGANISMS IN THE GEOCHEMICAL CYCLES."— Presentation transcript:
Ecosystems: Cycling of Matter SC STANDARD B-6.4: EXEMPLIFY THE ROLE OF ORGANISMS IN THE GEOCHEMICAL CYCLES
CN: p. NB Topic: Ecosystem Cycles EQ: How do nutrients move through biotic & abiotic factors in ecosystems?
The Water Cycle Water vapor condenses to its liquid phase in clouds and falls to Earth as precipitation. Some of this water percolates through the ground and is added to ground water. Other water runs off the surface and is added to bodies of water Water evaporates from plants in a process called transpiration. Warm water evaporates to water vapor, warm air rises.
The Carbon Cycle Plants use CO² from air and use it to make organic molecules (photosynthesis) and in the process release O² Herbivores eat the plants for energy and convert the organic molecules into ATP releasing CO²
The Carbon Cycle-2 The O² released during photosynthesis is used by many organisms to break down the organic molecules releasing ATP and CO² (cellular respiration) Carbon is also released through combustion (burning of organic molecules) using O² Carbon also released from swamps, animals, and is in volcanic eruptions
The Nitrogen Cycle Nitrogen must be cycled through an ecosystem so that N is available for organisms to make proteins and nucleic acids. Earth’s atmosphere is about 78% N² gas Most organisms cannot directly use N² gas Some bacteria have enzymes that allow them to break the triple bond in N² (N≡N) & then form NH³ (ammonia). This process is called nitrogen fixation Some nitrogen also fixed by lightning
The Nitrogen Cycle-3 Assimilation is the process by which plants absorb nitrogen Ammonification is the process by which nitrogen from animal waste or decaying bodies (in proteins or nucleic acids) is turned back to NH³ by bacteria.
The Nitrogen Cycle - 4 Nitrification: bacteria perform: NH³ nitrite nitrates (NO³) Denitrifcation: other bacteria take NO³ N² gas returning nitrogen to the atmosphere
Legumes have nodules on their roots which contain the nitrogen fixing bacteria
Phosphorus Cycle Phosphorus (P) is important part of ATP, RNA, & DNA molecules P is least common, does not enter atmosphere P is found in soil & rock as calcium phosphate When rain falls it dissolves releasing phosphate Phosphate can be absorbed by plant roots enters food chain Makes its way to oceans Used by marine organisms or deposited on ocean floor