PhotosynthesisPhotosynthesis

andand

Cellular Cellular RespirationRespiration

• All living things depend on energy

•ATP is used by all cells as their basic energy source

• Where does this ATP come from?

Where does Energy (ATP) come from?

Photosynthesis Cellular Respiration (aerobic)

What is it for?

Who does it?

Formula

Organelle

Reactions/location

Reactants

Products

If NO oxygen is present, then…

Autotrophs

use light energy from sun to produce food (sugars)

Heterotrophs

obtain energy from the food they consume

PhotosynthesisPhotosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

Cellular Respiration

PhotosynthesisPhotosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

glucoseglucose

SUN

Question:Question:

• Where does photosynthesis take place?Where does photosynthesis take place?

Plant LeafPlant Leaf

Cell Wall

Nucleus

ChloroplastChloroplast

Central Vacuole

ChloroplastChloroplast• OrganelleOrganelle where photosynthesisphotosynthesis takes place.

GranumThylakoidStroma

Two Parts to Photosynthesis

Two main parts of PhotosynthesisTwo main parts of Photosynthesis

Calvin Cycle Calvin Cycle akaLight Independent RxnLight Independent Rxn

• Occurs in the stroma

• Uses the ATP and NADPH

• Converts CO2 to glucose

Light Dependent RxnLight Dependent Rxn

• Occurs in the thylakoids

• Captures energyenergy from sunsun as ATPATP

NADPHNADPH

• Produces OO22

ThylakoidThylakoid

Granum

Has pigment chlorophyllchlorophyll – absorbs light

C6H12O6

Question:Question:

• Why are plants green?Why are plants green?

Chlorophyll MoleculesChlorophyll Molecules

• Located in the thylakoid membranesthylakoid membranes.

• Chlorophyll pigmentsChlorophyll pigments absorb light (blue blue and red).

• PlantsPlants are greengreen because the green wavelengthwavelength is reflectedreflected, not absorbednot absorbed.

ThylakoidThylakoid

Granum

Has pigment chlorophyllchlorophyll – absorbs light

Wavelength of Light (nm)Wavelength of Light (nm)

400 500 600 700

Short wave Long wave(more energy) (less energy)

Question:Question:

• During the fall, what causes the leaves to During the fall, what causes the leaves to change colors?change colors?

Fall ColorsFall Colors

• During the fall, the green chlorophyllgreen chlorophyll pigments are greatly reducedgreatly reduced revealing the other pigmentsother pigments.

What factors affect What factors affect photosynthesis?photosynthesis?

6CO2 + 6H2O C6H12O6 + 6O2

SUN

•intensity of sunlight

•water

•temperature