Transcript Elements are

Matter, Energy and Life
Building blocks of the Environment
To understand the environment, we need to
know how energy and matter behave in the
environment and in living things
Matter
Anything that takes up space and
has mass
Matter is made
up of different
elements
a carbon atom
Atoms are the
smallest particles
that are
characteristic of
an Element
Most matter can exist in three interchangeable
states:
as a solid, a liquid, or a gas
Elements are substances that cannot be broken
down into simpler substances by ordinary chemical
reactions
The Periodic Table of Elements shows all known
elements organized by their properties
Periodic Table of Elements
The table is
organized by
similarity in atomic
structure and
characteristics
Conservation of Matter
Under ordinary circumstances,
matter is neither created nor destroyed.
It is recycled endlessly.
Where did the elements come from?
The phrase ‘we’re all stardust’ is true!
Just four elements –
carbon, hydrogen, oxygen, and nitrogen make up over 96% of the mass of most
organisms.
Elements are joined by chemical bonds to form
molecules or compounds
Reactants
C
carbon
black
solid
+
O2
+ oxygen
colorless
gas
Products
CO2 + energy
carbon dioxide + energy
colorless gas
Chemical reactions, the breaking and forming of
molecular bonds, create the simple and complex
compounds and substances on which life depends.
Examples of
molecules
H2 + ½ O 2
H2 O
Water is a unique compound
Water:
- is the medium in which all of life’s chemical reactions
occur
- is a good electrical conductor
- has the highest surface tension of any common, natural
liquid
- is a liquid over a wide temperature range
- expands when it crystallizes, unlike most substances
Energy
The capacity to do work
heat, light, electricity, and chemical
energy are all types of energy
Energy can be:
Kinetic energy -- contained in moving objects or:
Potential energy – stored energy (physical, chemical
or nuclear)
Food has chemical energy: calories
High-quality energy is concentrated
This is very useful for doing work
Examples: Hot fire, high voltage electricity, boiling water
Low-quality energy is diffused or dispersed
This is not very useful for doing work
A lake contains a lot of heat energy even if its cold, but that heat
energy is not very useful because it’s not concentrated
Low-quality energy sources must be transformed
to high-quality sources to be very useful
Two Fundamental Principles of Energy:
Energy is conserved—it is neither created nor
destroyed but may be transferred or transformed
(First law of thermodynamics)
However, with each successive transfer or
transformation of energy, there is less energy
available to do work because it is dissipated and
disorder is increased
(Entropy increases ! (tendency of all natural
systems to move towards a state of increasing
disorder) - Second law of thermodynamics).
Organisms are highly organized and
require energy to maintain that
organization—they must fight entropy!
With every activity a cell or an organism performs,
some energy is lost or dissipated
• Organism (species)
• Population
• Biological
Community
• Ecosystem
• Biosphere
(ecosphere)
Food Web: Cross-connected Food Chains
(Cunningham & Cunningham 2002)
Simplified
Antarctic
Food Web
(Miller 2002)
(Enger & Smith 2002)
Cycle of Matter and Energy between the main
Structural Components of an Ecosystem
(Miller 2002)
Organisms in an ecosystem may be
identified by how they obtain their food.
(Miller 2002)
Quantification terms for
Biological material
• Biomass – estimate of the total mass,
or amount, of living material
• Productivity – the amount of biomass
produced in a given area during
a given period of time
Pyramid of Energy Flow
(Miller 2002)
Pyramid of Organism
Numbers?
(Miller 2002)
Pyramid of Organism
Biomass?
(Miller 2002)
Community-level Interactions
(Botkin & Keller 2003)
Key Points:
1. Matter and Energy are the fundamental building blocks of
the environment and organisms.
2. The periodic table of elements shows all the known
elements organized by atomic structure and chemical
properties.
3. Matter is made of elements that can combine to form
molecules and compounds by chemical reactions.
4. Matter and energy are conserved, but with each successive
reaction, energy is dissipated.
5. Potential energy is stored energy; Kinetic energy is a
release of energy by moving matter.
6. Life requires matter and energy—photosynthesis captures
solar energy to create life; respiration releases that stored
energy
Key Points:
7. An ecosystem is an environment interacting with a biological
community that is composed of populations which are
composed of individual organisms.
8. Primary producers fix energy and nutrients needed by
consumers.
9. A food chain or web (a connection of food chains by some
common organism(s)) is a sequence of organisms in which
energy and materials pass from one trophic level to another.
10. An organism’s feeding position in an ecosystem is it’s tropic
level.
Key Points:
11. Organisms in an ecosystem may be classified by: how
they obtain their food, their consumer level or their tropic
level.
12. Generally the transfer of energy in an ecosystem from one
tropic level to another is accompanied by roughly a 90%
loss.