Carbon Cycle

Key points

Carbon Cycle

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How Carbon moves

• Atmosphere to plants– Photosynthesis: CO2 to plant food– Carbon dioxide + Water + Light energy → Glucose + Oxygen– 6 CO2 + 6 H2O → C6H12O6 + 6 O2

• Plants to animals– Food chain: producers to consumers

• Plants and Animals to ground (Soil) – Died and then decompose– Some gets buried miles underground and turns into fossil

fuels in millions and millions of years.

Continue on how Carbon moves

• Living things to atmosphere– Respiration: animal and plants get rid of CO2 by exhaling

• Humans to the atmosphere– Burning fossil fuels– Each year 5 ½ billion tons of C is released…equals 100

million adult African elephants!

Continue on how Carbon moves

• Atmosphere to Ocean– Diffusion: ocean soak it up– Marine animals use it to build their skeletons and

shells• Marine animals to ocean floor– Die and drop to the floor– Eventually they form into limestone

Carbon Cycle Question

• We enjoy the taste of an apple because it is sweet. From where did the apple tree get the carbon to make sugar? – A. air– B. water– C. soil– D. nitrate fertilizer

Carbon Cycle Question

• The most abundant element in a wooden stick is carbon. Where did the carbon come from?– A. water– B. air– C. soil– D. fertilizer

Carbon Cycle Question

• Where do animals get the carbon found in their bodies?– A. from the air– B. from eating food– C. from the soil– D. from vitamins and minerals

Carbon Cycle Question

• For millions of years the carbon cycle has been in balance. Climatologists are concerned because data indicates the amount of carbon in the air is increasing. Which theory best explains this loss of atmospheric balance?– A. CFAs have created a hole in the ozone.– B. Society has increased the burning of fossil fuels.– C. Environmentalists have increased the size of rain

forests.– D. Our society has recognized the danger of nuclear

fission.

Carbon Cycle Question

• If the carbon dioxide in the atmosphere increases due to human activities, what do scientists predict will be the result?– A. increased cases of sunburn– B. warmer temperatures– C. increased incidence of earthquakes– D. more snowfall in the winter

Importance of Carbon

• Building block for life– Forms fossil fuels– Is used in complex molecules, such as DNA and

RNA, to control genetic reproduction in organisms.• RNA: to read the genetic information found in DNA and

to produce specific organic molecules used in the development and functioning of cells. It is a copy of a portion of DNA.• DNA: Coding for genetics and direct the development

and functioning of cells.

Nitrogen CycleKey Points

Nitrogen Cycle

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Importance of Nitrogen Allows plants and animals to make amino

acids, proteins and DNA Amino acids: use to make proteins Proteins: made of C, H, N, and other

elements, involved in almost all cell functions Forms: antibodies, contractile-movement,

enzymes, storage, structural support DNA: genetic coding to direct the

development and functions of cells.

How Nitrogen Moves Move from atmosphere to Plants

Fire, lightning, and nitrogen-fixing bacteria Changes it from N2 to the form which plants can use:

ammonium ion (NH4+) and nitrate (NO3

-) Bacteria live in the soil and on the roots of plants, which then

provides nitrogen to the plants Plants to Animals

Food Chain: Producers to consumers Plants and animals to soil

Animal waste Decay of organisms

Plants and animals to atmosphere Decay of organisms

Human impact on the Nitrogen Cycle Humans add to much nitrogen which off

balances the cycle Nitrogen-rich fertilizer and livestock waste

Affect: Increase nitrate (form of nitrogen) causes

plants to grow fast until they use up the supply and die

Increase in plants = increase in consumers and when the plants all die so do the consumers

Nitrogen Cycle Question Which letters on the cycle shows where

nitrogen is being “fixed” into a useable form for plants?  A. A, D B. B, C C. C, D D. A, B

Nitrogen Cycle Question How do plants get the nitrogen they

require for growth? A. the process of photosynthesis creates

nitrogen from sugar B. by absorbing it from holes in their

leaves and combining it with oxygen C. a symbiotic relationship with bacteria

that “fixes” nitrogen in the roots D. nitrogen from the air attaches itself to

the stem and leaves of plants.

Nitrogen Cycle Question Which of the following best explains why

animal manure can be used as a fertilizer for crops and gardens? The plant uses the A. carbon from the dead plant matter to

make sugar B. nitrogen to make proteins and DNA C. oxygen for cellular respiration D. hydrogen to form sugars

Carbon Cycle Question Which place on the nitrogen cycle shows

nitrogen in its LEAST useable form? A. A B. B C. C D. D