OBJECTIVES
• Summarize the steps of the water cycle in a
diagram.
• Explain how carbon and oxygen are cycled
through an ecosystem.
• Describe why nitrogen must cycle through an
ecosystem.
• Summarize the 3 major conversions of nitrogen in
ecosystems.
• Explain why it is important that phosphorus be
cycled through an ecosystem.
VOCABULARY
•
•
•
•
Carbon Cycle
Respiration
Nitrogen cycle
Phosphorus cycle
OBJECTIVES
• Summarize the steps of the water cycle in a
diagram.
• Explain how carbon and oxygen are cycled
through an ecosystem.
• Describe why nitrogen must cycle through an
ecosystem.
• Summarize the 3 major conversions of nitrogen in
ecosystems.
• Explain why it is important that phosphorus be
cycled through an ecosystem.
CYCLES
• Just as organisms are interconnected to each other
they are connected to the physical environment as
well.
• Name several examples of non-living things that
organisms, such as yourself, require to live.
• Oxygen, water, carbon, nitrogen, and phosphorus
are a few examples of these that we will discuss in
this section.
• Not what roles they play though. We already talked
about that in the previous chapter.
• You will learn how these substances cycle through
the ecosystems so that they may maintain their
availability to living organisms.
CYCLES IN NATURE
• Biogeochemical cycles = Cycles in which
water and minerals are recycled and reused
by moving from the non-living portion of the
environment into living things and back
again.
• Water Cycle
• Carbon Cycle
• Nitrogen Cycle
WATER CYCLE
• The water cycle continuously moves water
between the atmosphere, the land, and the
oceans.
• We see it first hand in several forms.
• Rain falls and is soaked up by the ground, or it pools
where it’s drank, or it will sit and evaporate back up
into the atmosphere.
• Since it’s a cycle there is no starting point.
• We’ll start with water forming in the atmosphere.
IN THE MARGIN OF YOUR NOTES, IDENTIFY THE STEPS NUMBERED 1-6.
Condensation
CONDENSATION
• First, water vapor condenses in the cool air of the
sky into the clouds we see.
• Even if there’s no clouds there is still plenty of water
there.
At any moment, the atmosphere contains an astounding 37.5 million
billion gallons of water, in the invisible vapor phase. This is enough
water to cover the entire surface of the Earth (land and ocean) with
one inch of rain.
http://whyfiles.org/2010/how-much-water-is-in-the-atmosphere/
PRECIPITATION
• When enough water accumulates in the
atmosphere it collects a water droplets, gets heavy,
and falls back to Earth.
• This, what we call rain, is also known as
precipitation.
RUN OFF & PERCOLATION
Some of this
water
percolates,
or is
absorbed or
soaked into
the soil and
becomes
groundwater
.
• Other water,
called runoff,
flows and
accumulates
across the
surface of Earth
and runs into
rivers, lakes, and
oceans.
TRANSPIRATION & EVAPORATION
• Once here if not consumed, the water is heated
by the sun and reenters the atmosphere as
water vapor by evaporation.
• Water also evaporates from trees and plants in
a process called transpiration (& animals in
perspiration…sweating).
IN THE MARGIN OF YOUR NOTES, IDENTIFY THE STEPS NUMBERED 1-6.
2
1
Condensation
3
6
4
5
4
NITROGEN CYCLE
• Nitrogen, another essential element, must also be cycled.
• The atmosphere is about 78% nitrogen gas, N2. But most
organisms cannot use nitrogen gas.
• The nitrogen cycle is all about getting the nitrogen in the
atmosphere into forms that can be used by organisms.
• Recall, Nitrogen is used for
• The amino acids of proteins.
• In the nitrogenous bases of DNA & RNA
• The nitrogen cycle is the process in which nitrogen
circulates among the air, soil, water, and organisms in an
ecosystem.
NITROGEN CYCLE
• In a process called nitrogen fixation,
bacteria convert nitrogen gas, N2,
into ammonia, NH3.
• N2  Nitrogen Fixation (Bacteria)  NH3
• Nitrogen-fixing bacteria
live in the soil and on the
roots of some plants.
NITROGEN CYCLE
• During
ammonification,
nitrogen from
animal waste or
decaying bodies
is returned to the
soil as ammonia
by bacteria and
decomposers.
NITROGEN CYCLE
• During nitrification,
ammonia, NH3, is
converted to nitrite
and then nitrate
NO3.
• Try not to confuse
this with nitrogen
fixation.
NITROGEN CYCLE
• Assimilation is the
process in which plants
absorb nitrogen. When
an animal eats a
plant, nitrogen
compounds become
part of the animal’s
body.
NITROGEN CYCLE
• During denitrification,
nitrate, NO3, is changed to
nitrogen gas, N2, which
returns to the atmosphere.
NITROGEN CYCLE: ON YOUR HANDOUTS,
LABEL THE PARTS OF THE CYCLE.
NITROGEN CYCLE: MACRO PERSPECTIVE
Assimilation
Ammonification
Nitrogen fixation
Denitrification
Nitrification
CARBON AND OXYGEN CYCLES
• Carbon and oxygen are critical for life on Earth,
and their cycles are tied closely together.
• Just as with water, these are both cycled so
organisms always have a supply available.
• The carbon cycle is the continuous movement of
carbon from the nonliving environment into living
things and back.
THE CARBON CYCLE
• Starting with atmospheric carbon
dioxide, the carbon cycle begins
with plants and other autotrophs
absorbing CO2 and converting
into usable sugars and starches.
• This process is known as
photosynthesis.
THE CARBON CYCLE
• Animals then eat this
vegetation.
• They break down the
sugars & starches
made by plants and
covert it into ATP, the
energy of
metabolism.
• In the process, they
release CO2 back
into the atmosphere.
• This process is called
cellular respiration.
THE CARBON CYCLE
• All life, plants, animals & everything else, eventually
dies.
• When it does it is broken down , decays, and collects
as fossil fuels.
• Fossil fuels, like oil
and gasoline,
accumulate after
millions of years of
this process of
death and decay.
THE CARBON CYCLE
• The burning of this fuel,
called combustion, also
releases carbon dioxide
back into the
atmosphere.
THE CARBON CYCLE
THE CARBON CYCLE: ON YOUR HANDOUTS,
LABEL THE PARTS OF THE CYCLE.
THE
CARBON
CYCLE
Man also plays
a role.
We are
responsible for
burning fossil
fuels, eating,
releasing
carbon
dioxide, and
dying.
These all
contribute to
the cycling of
carbon.
COMBUSTION
CONCEPTS SUMMARY
• These are the things you have been exposed to
and need to know:
1. What is the difference between food chains and
food webs.
2. Why energy is lost in a food chain.
3. The 3 main cycles of matter.
4. Why they are important.
5. What are the steps in the cycles.
ANSWERS
1. Which of the following organisms
can transform light energy into
chemical energy?
A. organism 1
B. organism 4
C. organism 7
D. organism 9
2. If a disease killed off all of
organism 2, which of the following
organisms would be most affected?
A. organism 3
B. organism 7
C. organism 8
D. organism 9
3.. During which of the following months is the rate of
photosynthesis greatest?
A. May
B. March
C. January
D. September
4. If the data were obtained from the atmosphere over an
evergreen forest, the curve likely would
A. rise from February to May and fall from August to
November.
B. vary less throughout the year.
C. rise steadily from January to December.
D. fall steadily from January to December.
5. If the y-axis of a graph displayed the rate of transpiration of
a deciduous forest, the curve likely would
A. rise from February to May and fall from August to
November.
B. vary little throughout the year.
C. rise steadily from January to December.
D. fall steadily from January to December.
PHOSPHORUS CYCLE
• Like water, carbon, oxygen, and nitrogen, phosphorus must be
cycled in order for an ecosystem to support life.
• Remember, phosphorus is an important element in ATP and DNA.
• It must cycle just like the other molecules.
• The phosphorus cycle is the movement of phosphorus in
different chemical forms from the surroundings to
organisms and then back to the surroundings.
CYCLE ILLUSTRATION ASSIGNMENT
• Due Next Tuesday.
• Choose any cycle studied.
• Find pictures to represent all the
participants in this cycle and make an
illustration of this cycle.
• Briefly outline this cycle in a paragraph on
your poster.
• Discuss details such as:
• The importance of the cycle.
CYCLE ILLUSTRATION ASSIGNMENT
• Due Next Tuesday.
• Choose any cycle studied.
• Find pictures to represent all the
participants in this cycle and make an
illustration of this cycle.
• Briefly outline this cycle in a paragraph on
your poster.
• Discuss details such as:
• The importance of the cycle.
CYCLE ILLUSTRATION ASSIGNMENT
• Due Next Tuesday.
• Choose any cycle studied.
• Find pictures to represent all the
participants in this cycle and make an
illustration of this cycle.
• Briefly outline this cycle in a paragraph on
your poster.
• Discuss details such as:
• The importance of the cycle.
CYCLE ILLUSTRATION ASSIGNMENT
• Due Next Tuesday.
• Choose any cycle studied.
• Find pictures to represent all the
participants in this cycle and make an
illustration of this cycle.
• Briefly outline this cycle in a paragraph on
your poster.
• Discuss details such as:
• The importance of the cycle.
SECTION 2 DISCUSSION QUESTION
• Construct a food chain with these organisms,
starting with the primary producer at the bottom
and the top consumer at the top.
• Human, grass, cow.
• Label who’s the producer, who’s the herbivore,
who’s the consumers, and who’s the omnivore.
• If there are 5050 calories produced in the producer
level, how many calories are made available to the
top consumer?
Each number represents an organism in the food web.
1.
Which of the following organisms
can transform light energy into
chemical energy?
A organism 1
B organism 4
C organism 7
D organism 9
2. If a disease killed off all of organism 2, which of the following
organisms would be most affected?
A organism 3
B organism 7
C organism 8
D organism 9
SECTION 3: DISCUSSION
• Energy can be dispersed through an ecosystem by
organisms consuming others, but organic
compounds and certain necessary resources, like
water, nitrogen, phosphorus, and carbon, are
cycled.
• Choose one of the 4 cycles and discuss 3 ways this
matter is cycled and 3 ways the cycling of this
matter is important.
• You have 3 minutes. Write them down and be
prepared to speak about them.
MRS. RYLAND PLACED A WATER PLANT IN A TEST TUBE, FILLED THE TEST TUBE WITH WATER, AND
THEN INVERTED THE TUBE IN A BEAKER HALF FILLED WITH WATER. SHE PLACED A LAMP NEXT TO
THE BEAKER AND TURNED ON THE LIGHT (SEE FIGURE 1). THE NEXT DAY THE CLASS SAW THAT THE
LEVEL OF WATER IN THE TEST TUBE HAD GONE DOWN (SEE FIGURE 2).
After seeing these results, Ella wrote four questions in her lab notebook.
• Question 1: Why did the water level in the test tube go down?
• Question 2: Is light needed to change the water level in the test tube?
• Question 3: Did light cause the water level in the test tube to go down?
• Question 4: Would a different type of plant change the water level in the test tube?
Ella set up an experiment to investigate one of her questions. She set up one test tube to look like Figure 1. She set up another test
tube similar to Figure 1 but without a lamp, and placed it in a dark closet. A day later, Ella checked the water level in each test tube.
1 . Which question could best be answered with her experiment?
A Question 1
B Question 2
C Question 3
D Question 4
2 . What was the dependent variable in the student’s experiment?
A the amount of light
B the amount of time
C the water level in the test tube
D the type of plant in the test tube
3 . What is the main substance found in the top part of the test tube labeled X in Figure 2?
A oxygen
B nothing
C water vapor
D carbon dioxide
1. During which of the following months is the rate
of photosynthesis greatest?
A.
B.
C.
D.
May
March
January
September
2.
If the data were obtained from the
atmosphere over an evergreen forest, the
curve likely would
A. rise from February to May and fall
from August to November.
B. vary less throughout the year.
C. rise steadily from January to December.
D. fall steadily from January to December.
3.
If the y-axis of a graph displayed the rate of
transpiration of a deciduous forest, the curve
likely would
A. rise from February to May and fall
from August to November.
B. vary little throughout the year.
C. rise steadily from January to December.
D. fall steadily from January to December.
QUICK LAB: IN-CLASS EXERCISE/DEMO
(20PTS)
You are a part of the carbon cycle. Every time you
exhale, you release carbon dioxide (CO2) into the
atmosphere. But the CO2 doesn’t stay CO2for long.
Questions:
1. Watch the demonstration and note the color
change of the bromthymol solution.
2. What do you think happened to the CO2 that was
exhaled into the solution?
3. How do plants, even aquatic plants, affect the
carbon cycle.
4.Draw the exchange of the CO2 and O2 in the
atmosphere and the processes that are involved.
PHOSPHORUS CYCLE
• Phosphorus is often found in soil and rock as
calcium phosphate, which dissolves in water to form
phosphate.
• The roots of plants absorb phosphate. Humans and
animals that eat the plants reuse the organic
phosphorus.
• When the humans and animals die, phosphorus is
returned to the soil.
THE PHOSPHORUS CYCLE