3 All living things need water because the cytoplasm in cells is composed mostly of water. The chemical reactions that support life must take place in water The electrical impulses produced by nerves are transmitted through water. Water cycle
4 How does water move through the environment? Precipitation – water falls from the sky as rain, snow or sleet Evaporation – water returns to the atmosphere as a gas Waste – animals release liquid waste Respiration – water is product of cellular respiration Runoff and streams carry water from place to place in the environment.
6 Why is carbon Important? All of the macromolecules contain carbon. Carbon is used to make sugars which provide living things with energy. The carbon containing macromolecules are the building blocks of all life.
7 How does carbon move through the environment? Photosynthesis – pulls CO2 from the air and uses it to make sugars. Consumption – one organism eats another and gets its carbon. Respiration – cellular respiration releases CO2 back to the air as it breaks down sugars
8 How does carbon move through the environment? Decomposition – as dead organisms are broken down, the carbon is released to the soil or back to the air. Deposition – the remains of dead organisms can be converted to fossil fuels Burning – releases CO2 back to the air when organisms or fossil fuels are burned.
10 Why is Nitrogen important? Nitrogen is an element that is found in amino acids. Amino acids join together to form proteins Proteins help living things carry out life processes.
11 How does Nitrogen move through the environment? Nitrogen gas makes up most of our air but organisms can’t use it in this form. Nitrogen fixation – bacteria, lightning and fertilizer factories take Nitrogen from tha air and convert it into forms organisms can use Plants take in nitrates from the soil to make amino acids
12 How does Nitrogen move through the environment? Consumption – organisms eat each other and obtain their nitrogen Decomposition and waste return nitrates to the soil. Denitrification – bacteria return nitrogen back to the air.
14 Why is phosphorus important? Phosphorus is found in nucleotides. Nucleotides join together to form nucleic acids Nucleic acids control cell functions
15 How does phosphorus move through the environment? Consumption – organisms eat each other and obtain phosphorus Decomposition and waste return it to the soil Plants acquire P from the soil Weathering – rain breaks down rocks and release the phosphorus they contain.