Transcript Food For Thought – Energy

Food For Thought – Energy
Energy
• Capacity to perform work
• Kinetic energy = motion
• Potential energy = stored
energy
Energy is always
conserved
• It cannot be created nor
destroyed
• Available in different forms
• Light energy
• Heat energy
• Chemical energy
• Mechanical energy
Energy is always
conserved
• It can not be created or destroyed
• Can be converted from one form to
another
Ex: gasoline  movement and heat
When converting energy,
some is always ‘lost’ as heat
• Solar energy hitting earth daily = energy
of 100 million atomic bombs
• Less than 1% is converted to chemical
energy by photosynthesis
The Environment and
Energy
• Energy – the ABILITY to do WORK
• All LVING ORGANISMS use energy for
life processes.
How do we get our
energy?
Producers
• Green Plants
• Capture light
energy from the
sun and convert it
into food energy.
Consumers
• Animals that
depend upon
green plants and
other animals for
food.
Different organisms get
energy in different ways
• Autotrophs -- organisms that can
make their own food (green plants)
• Heterotrophs -- organisms that
cannot make their own food and
have to feed on autotrophs or other
heterotrophs (cows)
Consumers = Heterotrophs
Producers = Autotrophs
Respiration?
Converting energy in living
organisms
Photosynthesis and
Respiration
ATP (Adenosine Triphosphate)
• The form of energy used by cells for cell
activities
• Energy stored in ATP is BROKEN DOWN
by ATPase, an ENZYME, to a molecule
of ADP. When that chemical bond is
broken, energy is released.
ATP
Adenosine triphosphate
It takes energy
to make ATP
Breaking down
ATP releases energy
ATP (Adenosine Triphosphate)
• All organisms get their ENERGY
from ATP.
• Without ATP all living organisms
will DIE.
Photosynthesis & Respiration
PHOTOSYNTHESIS
• Production
• Harvests sunlight energy
• Converts to chemical
energy
• Stores energy in form of
organic molecules
(glucose)
RESPIRATION
• Consumption
• Breaks down
organic molecules
into chemical
energy
Photosynthesis and
Respiration Form a Cycle
Photosynthesis
• Converts light energy into chemical energy
(ATP, NADPH)
• Chemical energy and CO2 made into sugars
• Requires H2O, CO2, and sunlight
Photosynthesis
6CO2
+ 6H2O
---------->
C6H12O6 +
O2
CARBON +WATER SUNLIGHT SUGAR + OXYGEN
DIOXIDE
Three Phases
• Light absorption by CHLOROPHYLL
• Light Dependent reactions – water is
SPLIT into HYDROGEN and OXYGEN.
OXYGEN is released and energy is
transferred to the next phase.
• Light Independent reactions – carbon
dioxide and WATER are combined to
form CARBOHYDRATES
Factors affecting
Photosynthesis
•
•
•
•
•
Amount of LIGHT
Intensity of the LIGHT
Amount of WATER
DIRECTION of the light
Temperature
Fuel
Oxygen
Heat
Respiration
• The release of energy from sugar
molecules
C6H12O6 +
O2
----------> 6CO2
+ 6H2O
SUGAR + OXYGEN ENZYMES CARBON +WATER
DIOXIDE
How They Fit in
Trophic Levels
Types of Consumers
• Primary Consumer (Herbivores) – eat
PLANTS to get energy
• Secondary Consumers (Carnivores,
omnivores) – eat ANIMALS to get energy
• Tertiary Consumers (Carnivores,
omnivores) – eat ANIMALS to get energy
Decomposers
• Break down and DECOMPOSE DEAD
ORGANISMS getting
energy and releasing nutrients back into
the environment.
You Are What You Eat
• Food Chains – a
simple LINEAR
drawing showing
which organisms feed
upon which others
You Are What You Eat
• Food Web – A
NUMBER OF
INTERCONNECTING
FOOD CHAINS
How organisms obtain
energy
• ECOSYSTEMS are powered by energy
from the SUN
• Energy only enters living things at the
PRODUCER level.
• As energy is passed along the FOOD
chain, much of it is lost as HEAT.
How organisms obtain
energy
• Energy flows ONE way through the food
chain, from PRODUCERS through
CONSUMERS.
• Each level of the food chain has LESS
available energy in it.
Pyramids of Numbers
• Numbers decrease as
we go from one food
level to the next.
Numbers that
decrease are
BIOMASS,
AVAILABLE
ENERGY, and
organism
population size.