Transcript Cycling & Recycling of Matter

CYCLING & RECYCLING OF
MATTER
2.1
The Water Cycle – Key Terms









Condensation: the collecting of water molecules from the vapour state to
form the liquid state. Also, the formation of clouds
Precipitation: any form of moisture condensing in the air and depositing on
the ground. Ex: rain, snow, hail, fog, etc…
Capillarity: the ability of water to move into small root capillaries of plants.
Percolation: the process of water seeping through cracks and pores in rocks
and soil.
Groundwater: a layer of water in the ground formed through percolation.
Surface runoff: when water does not percolate, but rather it runs over the
surface of the soil.
Evaporation: molecules leaving the liquid sate and entering the vapour or
gaseous state (happens from land and water).
Horizontal movement: the movement of a weather system into an area.
Transpiration: the loss of water vapour from plants.
FYI





Life has 5 major requirements
Energy, Water, Inorganic Carbon, Oxygen, &
Nutrients
Oxygen and nutrients are generally combined
with carbon and oxygen. We call these
mixtures “organic compounds”.
When we study carbon based compounds we
are studying organic chemistry.
Why is this important?
FYI
Organic compounds form
covalent bonds (the result of
sharing electrons) and it is the
“cycling” of these organic
compounds that allows these
bonds to be broken which
releases energy and smaller
compounds. At the same time
new bonds are built up during
synthesis reactions.
 Again why do we care about the
cycling of carbon compounds??

The Importance of Cycling


Because our biosphere contains a limited
(or finite) number of atoms, and new
compounds can only be formed from
those atoms that are released during
cycling.
It is essential that matter be recycled to
help balance our biosphere and maintain
life on earth.
 The cycling of organic compounds happens
in 2 ways
 Eating and digestion
 Decay and decomposition
Important elements and compounds



C – carbon is a component of
organic molecules of which all
organisms are composed
CO2 – carbon dioxide is necessary
for photosynthesis which is needed
to begin the food chains and food
webs
O2 – oxygen (gas) is necessary for
most living things
Important elements and compounds




H2O – water is necessary for all
organisms
C6H12O6 – sugar (glucose) is a form of
food storage in plants and a source of
energy of organisms
N – nitrogen is a component of
proteins and nucleic acids (DNA;
Chromosomes)
N2 gaseous nitrogen is the most
abundant gas found in the air



NO3 – nitrate is a useable form
of nitrogen; often formed by
bacteria in the soil and on roots
P – phosphorous is found in
energy storage called ATP; also
found in nucleic acids
PO4 phosphate is a common
form of phosphorous found in
rocks, soil, limestone etc…
Homework NOW!

Page 51: 1, 2, 4, 5