Transcript 6CO 2
Photosynthesis:
Life from Light and Air
Energy needs of life
All life needs a constant input of energy
Animals = Heterotrophs
get their energy from “eating others”
eat food = other organisms = organic molecules
make energy through respiration
Plants = Autotrophs
get their energy from “self”
get their energy from sunlight
build organic molecules (food) from CO2
make energy through photosynthesis
Photosynthesis: the process that uses the sun’s
energy to make simple sugars, such as glucose.
6CO2 + 6H2O → C6H12O6 + 6O2
Carbon Dioxide + Water → Glucose + Oxygen
How do plants live?
Photosynthesis
Energy building reactions
collect sun energy
make ATP
Sugar building reactions
use ATP for energy
use CO2 as carbon for new sugars
build sugars
glucose, cellulose, starch
build all other organic molecules
proteins, lipids, carbohydrates, DNA
store energy for future use
starch in seeds & roots
Photosynthesis
Actually 2 separate reactions
Energy building
Energy
building
reactions
use sunlight
make energy (ATP)
sun
Sugar building
use ATP
ATP
ADP
Sugar
building
reactions
use CO2
make sugars (C6H12O6)
CO2
sugar
Chloroplasts
CO2
absorb
sunlight & CO2
make
energy & sugar
Contain chlorophyll
Light-Dependent Reactions
H2O +
light ATP + O
2
energy
H2O
makes ATP energy
releases oxygen
sunlight
as a waste product
Energy Building
Reactions
ATP
O2
Light-Independent Reactions
CO2 + ATP C6H12O6 + ADP
CO2
ADP
builds sugars
uses ATP
cycles ADP back to
Sugar make
Building
Reactions
ATP
sugars
C6H12O6
more ATP
Putting it all together
CO2 + H2O + light C6H12O6 +
energy
H2O
CO2
sunlight
ADP
Plants make both:
ATP
sugars
Sugar
Building
Reactions
Energy
Building
Reactions
ATP
O2
O2
sugars
C6H12O6
So what does a plant
need?
Bring In
leaves
CO2
H2O
light
Let Out
O2
Move Around
shoot
roots
sugars
6CO2 + 6H2O + light C6H12O6 + 6O2
energy