Announcements Homework packet due Thursday/Friday – Questions so far? Quiz on Thursday/Friday

Biogeochemical Cycles

Why do we need to eat? Give some detail. “To live” is not a good answer.

Nutrients are chemicals that organisms need to build tissue and carry out life functions – Examples: Carbon, Nitrogen, Phosphorous

Why do I need... Carbon – Needed for proteins, lipids, carbohydrates, and nucleic acids – Forms calcium carbonate (CaCO 3 ) for skeleton

Why do I need... Nitrogen – Needed for amino acids, the building blocks of protein Phosphorous – Important part of nucleotides, the building blocks of nucleic acids

Left Page Processing Write an acrostic poem explaining the importance of nutrients N U T R I E N T

Biogeochemical Cycles Matter (such as nutrients) is recycled in an ecosystem by a combination of biological, geological, and chemical processes

Ex. eating, breathing, “burning” food, eliminating waste Ex. Forming clouds, precipitation, flow of running water, lightning Ex. Volcanic eruptions, forming/breaking down rock, shifting plates

Left Page Processing Create a diagram that illustrates examples of each of the three parts of biogeochemical processes.

Carbon Cycle This figure shows how carbon moves through the biosphere. Carbon dioxide is continuously exchanged between the atmosphere and ocean through chemical and physical processes.

Carbon Cycle Plants take in carbon dioxide during photosynthesis and use the carbon to build carbohydrates. Carbohydrates then pass through food webs to consumers.

Carbon Cycle Organisms release carbon in the form of carbon dioxide gas by respiration. Also, when organisms die, decomposers break down the bodies, releasing carbon to the environment.

Carbon Cycle Geologic forces can turn accumulated carbon into carbon-containing rocks or fossil fuels. Carbon dioxide is released into the atmosphere by volcanic activities.

Quick Check 1.A carbon atom is in the atmosphere. Where can it go next? 2.A carbon atom is in a fish. Where did it probably come from? 3.A volcano erupts. Where did it take carbon from? Where will it move the carbon to?

Imagine, for a moment, that you are a carbon atom in a molecule of carbon dioxide that has just been shot out of a volcano. The leaf of a blueberry bush in a nearby mountain range absorbs you during photosynthesis. You become part of a carbohydrate molecule in a blueberry. A caribou eats the fruit, and within a few hours, you are passed out of the animal’s body. You are soon swallowed by a dung beetle, which gets eaten by a hungry shrew. You are combined into the body tissues of the shrew, which is then eaten by an owl. You are released back into the atmosphere when the owl exhales carbon dioxide, dissolve in a drop of rainwater, and flow through a river into the ocean.

Nitrogen Cycle

Quick Check 1.A nitrogen atom is in the atmosphere. What are 2 ways it can move to the soil? 2.A nitrogen atom is in the soil. Where can it go next? 3.A nitrogen atom just rejoined the atmosphere. Where did it come from?

Left Page Processing Write a story following an atom of nitrogen through the nitrogen cycle. It needs to have at least five stops with both biological and geological changes.

Summary Do all nutrient atoms travel the same path? Explain. Can nutrients ever be used up? Explain.