Transcript Cycling of Matter

Cycling of Matter
Warm Up
 Difference between abiotic & biotic factors
 Abiotic factors affecting oak tree growth
 Southern ON  Arctic - vegetation change
 Stream is an aquatic ecosystem, but also
part of a forest ecosystem??
Learning Goals
 Understand that nutrients move through
ecosystems in cycles
 Describe the processes by which water,
nitrogen and carbon are moved through
ecosystems
 Describe the relationship between
photosynthesis and cellular respiration
What Sustains Life on Earth?
 Solar energy
 The cycling
of matter
 Gravity
 Nutrients are
recycled,
energy is not
(enters as
sunlight,
leaves as heat)
Nutrient Cycles
 Nutrients in food provide energy & matter
needed to stay alive  carbohydrates, fats,
proteins, vitamins, minerals
 Elements: pure substances that cannot
be broken down into simpler substances
that make up nutrients
 Animals obtain C, H, O, N they need from
eating
 Plants absorb CO2 from air, H2O & nitrates
from soil
Nutrient Cycles
 Nutrient Cycle: the process of moving a
nutrient back & forth between biotic and
abiotic parts of ecosystems
 Can occur quickly or remain in one place
for a long time
 Reservoir: any place where matter builds
up
Water Cycle
1. Sun’s heat warms surface H2O which evaporates
into atmosphere
2. In atmosphere
 exists as water
vapour
3. Water vapour
cools, condensing
into clouds  falls
as precipitation
Water Cycle
4. Hits ground, runs off into streams/rivers (“run
off”)
5. Some seeps
through soil into
ground water 
may flow into
large underground
lakes (“aquifers”)
or wetlands or
oceans
Water Cycle
6. Some H2O on the surface or in the soil is taken
up by animals or plants (“root uptake”)
7. Plants release
water vapour into
the atmosphere
through their
leaves
(“transpiration”)
8. Water vapour
rises into the
atmosphere,
continuing the
cycle
Homework – Water Cycle
1. What are 2 processes that cause water to
enter the atmosphere?
2. Give an example of how water moves
from the biotic to the abiotic part of an
ecosystem.
3. How is the cycling of nutrients different
from the movement of energy in an
ecosystem?
Nitrogen Cycle
 Organisms need N to make proteins
 The atmosphere is 78% N but it must be
converted into ammonia via nitrogen
fixation to be useful
Nitrogen-fixing
bacteria found in root
nodules of legume plants
(beans, peas) as well as
in soil and water do this
Nitrogen Cycle
 Nitrifying bacteria then convert ammonia
into nitrites and then nitrates, which plants
can absorb
 Animals get N from eating plants or other
animals  a waste product of protein
digestion is ammonia
 Bacteria & fungi in soil break down ammonia
in waste & dead organisms into
nitrates/nitrites
 Released back into soil to be absorbed by plants
 Denitrifying bacteria in soil convert nitrates
back to N(g) to return N to the atmosphere
Homework - Nitrogen Cycle
1. What types of bacteria are involved in the
nitrogen cycle, and what does each do?
2. What would happen to nutrient cycling if
an unknown disease were to kill all the
bacteria/fungi in an ecosystem?
Carbon Cycle
 The atmosphere is 0.04% CO2  all the C
plants need comes from this
 Biotic reservoir = world’s forests
 Abiotic reservoirs = fossil fuels
(underground coal, oil, natural gas);
oceans (dissolved CO2 used by marine
organisms to build tissue)
 Photosynthesis & cellular respiration move
carbon between these reservoirs…
Photosynthesis
 The Sun’s energy is captured by
chlorophyll in plants and converted into
chemical energy, which can be stored as
sugar
Photosynthesis
CO2(g) + H2O + Sunlight  Glucose + O2(g)
Used
Produced
Cellular Respiration
 Plants store energy in the form of glucose
(sugar) which they make from sunlight
 Cellular respiration: process where
glucose is combined with O2(g) to form
CO2(g) and H2O, and to release energy for
use by an organism’s cells
 Both plants and animals carry out C.R.,
but animals must obtain glucose from
foods they eat
glucose + O2(g)  CO2(g) + H2O + energy
Homework - Carbon Cycle
1. List 1 abiotic & 1 biotic carbon reservoir.
2. What is the role of photosynthesis in the
ecosystem?
3. How are photosynthesis and cellular
respiration related?
4. Why do plants need cellular respiration?
https://www.youtube.com/watch?v=2D7hZpIYlCA
https://www.youtube.com/watch?v=leHy-Y_8nRs