Obtaining Food Life can be thought of as solar-
powered All energy comes from the sun
Potential and Kinetic Energy
How is all energy divided?
PotentialEnergy
Kinetic
Energy
All Energy
Gravitation
PotentialEnergy
ElasticPotentia
lEnergy
ChemicalPotentialEnergy
What is Potential Energy?
o Energy that is stored and waiting to be used later
What is Gravitational Potential Energy?
o Potential energy due to an object’s position
o P.E. = mass x height x
gravity
Don’t look down, Rover!
Good boy!
What is Elastic Potential Energy?
o Potential energy due compression or expansion of an elastic object.
Notice the ball compressingand expanding
What is Chemical Potential Energy?
o Potential energy stored within the chemical bonds of an object
What is Kinetic Energy?o Energy an object has
due to its motiono K.E. = .5(mass x
speed2)
Autotrophs Greek for “self feeder” (make their
own food) Also called producers Use sunlight and CO2 to make
glucose Called photosynthesis
On land :plants In water: algae
Heterotrophs Greek for “other
eaters” Must eat
producers for energy
Harvesting energy in food
We use food to make energy through cellular respiration Use oxygen and sugar to make energy in the
form of ATP
Plants use sunlight to make energy through photosynthesis Use CO2 and water to convert sunlight into
chemical energy The two processes are related!!! We need
plants and plants need us.
Before the energy can be used, it is first transformed into a form which the organism can handle easily.
This special carrier of energy is the molecule adenosine triphosphate, or ATP.
Its Structure The ATP molecule is composed of three components.
At the center is a sugar molecule, ribose (the same sugar that forms the basis of RNA).
Attached to one side of this is a base (a group consisting of linked rings of carbon and nitrogen atoms); in this case the base is adenine.
The other side of the sugar is attached to a string of phosphate groups.
These phosphates are the key to the activity of ATP.
ATP Made in the _______________________. Adenosine Triphosphate A currency for cells to convert food
into a usable energy source. Think a $100 bill is glucose and ATP
is a $1 bill. It is easiest to use the $1
Types of energy Energy- the ability
to perform work
Potential – stored energy/ energy of location Chemical energy-
how much work the molecules can do is dependant on how the molecules are arranged.
Carbs, lipids, proteins have structures that make them rich in energy
Chemical energy is the energy that is available for release in chemical reactions
Kinetic- energy of motion Thermal energy- random molecular
motion
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