Chapter 2 Chapter 2 Cycles of Matter 2.1 The Role of Water in Cycles of Matter 2.2 Biogeochemical Cycles 2.3 the Balance of the Matter and Energy Exchange 2.1 The Role of Water in Cycles of Matter In this section you will: Explain water s primary role in the biochemical cycles as a result of its chemical and physical properties Analyze data on water consumption and loss in plants and animals Evaluate the use of water by society Penny Boat Look at some of waters unique properties How many pennies can fit into a boat before it sinks? How many drops of water can be put on a penny? 10 minutes. 1
Water Crash Course - https://www.youtube.com/watch?v=hvt3y3_ghgg 2.1 The Role of Water in Cycles of Matter Limited amount of water on Earth Water product of cellular respiration Water exists in the environment as a solid, a liquid, and a gas. Recycled through the hydrological cycle- water cycle Universal Solvent Solvent- Solute- Water dissolves a wide range of substances. Hydrogen bonding and polarity play key roles in determining water s properties Ability to dissolve and transport materials. What are water s other unique properties? Water is essential for humans and ecosystems. Drought and poor water quality can affect water availability and impact humans and the environment. 2
Hydrological Cycle Hydrologic Cycle The hydrologic cycle plays a central role in nutrient cycles (biogeochemical cycles). Thought Lab 2.1 2.2 Biogeochemical Cycles Pg. 38 Procedure and Analysis Questions In this section you will: Summarize the biogeochemical cycling of carbon, oxygen, nitrogen, sulfur, and phosphorus Relate biogeochemical cycles to the reuse of all matter in the biosphere Design an experiment to compare the production of carbon dioxide in plants and animals Measure and record properties and chemical compositions of water samples Identify human activities that can affect cycles of matter Predict the effect of human activities on various biogeochemical cycles 3
Cycles Carbon and Oxygen Cycle Limited amount of matter in ecosystem, chemicals must be constantly recycled Main biogeochemical cycles: Oxygen Carbon Nitrogen Sulfur Phosphorous Closely related in our ecosystem Carbon and oxygen are found in living organisms, land, atmosphere, and water. Slow vs. Rapid Cycling of Carbon Note: All cycles having storage of nutrients (soil, air, organisms). Organisms are involved in rapid cycling of carbon Substances can be moved between nutrient reservoirs quickly Ex. Carbon moving from producer to consumer What processes would contribute to this cycling? Photosynthesis Cellular Respiration Large producers can store carbon for long periods of time Substances accumulate and are unavailable for long periods of time Ex. Fossil fuel deposits Not recycled until tree dies or broken down by decomposers Carbon Sinks Carbon Sink- storehouse of carbon in biosphere Due to slow cycling Largest stores= Earth s ocean Water contains dissolved carbon dioxide Other stores include forests, limestone, and petroleum deposits 4
What human activities influence carbon cycling? Ozone Layer Protects earth from UV radiation 99% of UV radiation is screened and never reaches Earth s surface Ozone holes: Above the poles (N/S) Increase in skin cancer and eye problems Major cause? CFC s- chlorofluorocarbon CFC s- Chlorofluorocarbon CFC s released in sprays and as waste product Upper ozone layer reacts with chlorine and cause a breakdown in the our UV protective layer CFC s remain in atmosphere for long periods of time May continue to break down ozone layer Solutions? Greenhouse Gases Atmospheric gas capable of absorbing infrared radiation Traps and holds heat in atmosphere Greenhouse effect Global warming 5
Sulfur Cycling Acid Deposition Sulfur cycles through biosphere Important component of vitamins and proteins Bacteria use sulfur compounds in photosynthesis and cellular respiration Also release sulfur in forms that cannot be used by other organisms Fossil fuels, oil, coal, natural gas How could this stored environmental sulphur be released naturally? Weathering Volcanic activity How could this be a problem? Acid rain= Acid deposition Nitrogen Cycling Nitrogen found throughout biosphere Makes up 78.1% of atmosphere Required by organisms to form amino acids Proteins that make DNA Nitrogen gas cannot be used to make amino acids Must be converted into other forms for use Nitrogen Fixation Bacteria convert N 2 to nitrates (NO 3 -) and ammonium ions (NH 4 +) Nitrogen-fixing bacteria NH 4 is also produced when decomposers break down organic matter Denitrification = bacteria turning nitrite and nitrate into nitrogen gas (atmospheric nitrogen) Typically occurs in anaerobic environment Anaerobic- no oxygen 6
Phosphorous Cycling Overabundance of Phosphorous Phosphorus does not cycle through atmosphere Found in soil and water Large amounts stored in rock and released during erosion Required for cellular materials DNA Phospholipids ATP Most phosphorous locked in rocks and sediment limiting plant growth However, adding excess phosphorous can cause uncontrolled algae growth and plant life Reducing oxygen in aquatic ecosystem Crash Course- Nitrogen/Phosphorous Cycles Carbon, oxygen, sulfur, nitrogen, and phosphorus are all recycled through biotic and abiotic processes. They are stored in nutrient reservoirs and cycle through these reservoirs at different rates. Because biogeochemical cycles are interrelated, disruptions in one cycle can affect another. Review Crash Course- https://www.youtube.com/watch?v=lehy-y_8nrs 7
Algal Blooms What causes them? Eutrophication build up of excess nutrients! TOO MUCH PHOSPHORUS Soaps Laundry detergents Why are these bad? Some algae contain neurotoxins!! What are neurotoxins?? Yikes they affect your nervous system (i.e brain) Dinoflagellates Red Tide- Dead Zones How Does It Affect Humans? Homework Irritation of the eyes, nose, throat, tingling lips and tongue are common symptoms that often occur during red tides. Dispersal of toxins due to waves, wind and boat propellers in high concentrations of red tides into air causing problems along shoreline. Causes severe or chronic respiratory conditions Emphysema or asthma 8
2.3 The Balance of the Matter and Energy Exchange In this section you will: Explain how energy, matter, and the productivity of ecosystems are interrelated Explain the influence on atmospheric composition of the equilibrium between the exchange of oxygen and carbon dioxide in photosynthesis and cellular respiration Decribe evidence and scientific explanations for change in the composition of Earth s atmosphere from past to present, and describe the significance of these to current states of equilibrium in the biosphere Oultine, explain, and evaluate the influence of human activities on the biosphere Design and evaluate a model of a closed biologival ecosystem Productivity Productivity- Rate at which ecosystem s producers capture and store energy within organic compounds over certain length of time. Amount of sunlight area receives determines productivity Productivity rates often expressed as energy or biomass Moisture plays significant role in ecosystem Thought Lab Pg. 54 Work with partner Analysis questions 1-4 Balance in Biosphere Bodies maintain homeostasis What is homeostasis? We must use energy to maintain balance Global level? Earth is self-regulating 9
Gaia Hypothesis 1979, James Lovelock proposed the Gaia Hypothesis- Homeostasis on global level Life plays role in balance of biosphere Composition of atmosphere Photosynthesis Cellular Respiration Sediment make up geological features Stromatolites- formation of sedimentary rocks and cellular debris from organisms Layers of oxygen trapped in ion oxides Later years moved from ocean to atmosphere Replicating Earth s Biosphere Scientist have tried to replicate on small scale Not successful Biosphere extremely complex Human Interference Ability to change surroundings Change causes disruption in flow of matter and energy Interrupts natural balance of ecosystems Must find ways to reduce human impact Preserving Natural Balance Alternative energy sources Land use Farming Clear cutting 10
Homework Pg. 61 #1-7 11