Photosynthesis: Life from Light and Air

1
(No Transcript)
2
Photosynthesis Life from Light and Air
3
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

4
Photosynthesis

• This is the equation you are used to seeing, but
  this is not the whole story

5
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

6
Photosynthesis

• Actually 2 separate reactions
• Energy building
• use sunlight
• make energy (ATP)
• Sugar building
• use ATP
• use CO2
• make sugars (C6H12O6)

Energybuilding reactions
ATP
ADP
Sugarbuilding reactions
sugar
7
Chloroplasts
absorbsunlight CO2
Leaf
Leaf
Chloroplasts
Chloroplasts contain Chlorophyll
Chloroplast
makeenergy sugar
8
Energy Building Reactions
light energy
?
H2O
O2


ATP
H2O

• makes ATP energy
• releases oxygenas a waste product

sunlight
Energy Building Reactions
ATP
O2
9
Sugar Building Reactions
?
CO2
ADP


C6H12O6
ATP

• builds sugars
• uses ATP
• cycles ADP back to make more ATP

CO2
ADP
SugarBuilding Reactions
ATP
sugars C6H12O6
10
Putting it all together
H2O
CO2

• Plants make both
• ATP
• sugars

sunlight
ADP
SugarBuilding Reactions
Energy Building Reactions
ATP
sugars C6H12O6
O2
11
So what does a plant need?

• Bring In
• CO2
• H2O
• light
• Let Out
• O2
• Move Around
• sugars

leaves
shoot
roots
12
Leaf Structure
O2
H2O
CO2

• gases in out
• water out
• transpiration

H2O
CO2
O2
13
Stomates

• Function of stomates
• CO2 in
• O2 out
• H2O out

guard cell
stomate
14
(No Transcript)
15
Xylem
carry water up from roots
16
Phloem food-conducting cells

• carry sugars around the plant wherever they are
  needed
• new leaves
• fruit
• seeds

17
Putting it all together

• Making a living
• sunlight
• leaves solar collectors
• photosynthesis
• gases CO2 in O2 out
• stomates gases in out
• H2O
• roots take in water from soil
• pulled up by leaf evaporation
• nutrients
• roots take in from soil

18
How are they connected?
Respiration
Photosynthesis
19
Energy cycle
Photosynthesis
plants
CO2
O2
animals, plants
Cellular Respiration
ATP
20
The poetic perspective

• All of the solid material of every plant was
  built out of thin air
• All of the solid material of every animal was
  built from plant material

sun
Then all the cats, dogs, mice, people
elephantsare really strands of air woven
together by sunlight!
21
Any Questions??