Photosynthesis

Biology

IntroductionIntroduction PHOTO PHOTO = light = light SYNTHESIS SYNTHESIS = putting together= putting together The synthesis of The synthesis of glucoseglucose (sugar) from (sugar) from

sunlightsunlight, , COCO22, and , and HH22OO OO22 is a waste product is a waste product AutotrophsAutotrophs (green plants, algae) trap (green plants, algae) trap

energy from the sun and build sugars like energy from the sun and build sugars like glucose and starch.glucose and starch.

****Life on earth DEPENDS on photosynthesisLife on earth DEPENDS on photosynthesis****

Pigments and SunlightPigments and Sunlight Leaves of plants contain chlorophyll, a Leaves of plants contain chlorophyll, a

green colored pigment. green colored pigment. Chloros Chloros = = pale greenpale green; ; phyllon phyllon = = leafleaf Chlorophyll reflects green and some Chlorophyll reflects green and some

yellow light while it absorbs the energy of yellow light while it absorbs the energy of all other colors of light.all other colors of light.

Plants look green to us!

First Steps to First Steps to PhotosynthesisPhotosynthesis

Chloroplasts traps energy from the Chloroplasts traps energy from the sunsun

LightLight energy converted to chemical energy converted to chemical energy (sugar such as glucose)energy (sugar such as glucose)

Energy stored as starchEnergy stored as starch water comes from the gound and water comes from the gound and

COCO2 2 from the airfrom the air

Photosynthesis FormulaPhotosynthesis Formula

66 CCOO22 + + 66 HH22O O CC66HH1212OO66 + 6 + 6 OO22

Sugar made here!

Oxygen (O2) made here!

Leaf structure (inside)Leaf structure (inside)

Water from soil, roots

CO2 from air

Chlorophyll

Oxygen

Chlorophyll is in Chloroplasts in Leaves

Chloroplast

Photosynthesis takes place here

Chloroplasts

Leaf X-Section

Real chloroplasts in algae

Two Reactions:Two Reactions:

Light Dependent ReactionsLight Dependent Reactions

Calvin CycleCalvin Cycle

Light Dependent Light Dependent ReactionsReactions

Water is split apart by sunlight:Water is split apart by sunlight:

Hydrogen (H)

H2OOxygen (O2)

Light Dependent ReactionsLight Dependent Reactions

OxygenOxygen diffuses out the leaf for us to diffuses out the leaf for us to breathe.breathe. Hydrogen is used to make Hydrogen is used to make ATP’s ATP’s and is and is

also used in the Calvin Cycle to make also used in the Calvin Cycle to make sugars like glucose and starch.sugars like glucose and starch.

Hydrogen carried toHydrogen carried to Calvin cycle by:Calvin cycle by: NADP – H “truck”NADP – H “truck”

NADP

NADP Truck

Calvin CycleCalvin Cycle Starts with a chemical the holds onto Starts with a chemical the holds onto

COCO22

from the air.from the air. An enzyme named Nabisco (opps I mean An enzyme named Nabisco (opps I mean

Rubisco) helps to fix CORubisco) helps to fix CO2 2 from the air.from the air. NADP – HNADP – H drops off drops off

it’s hydrogen it’s hydrogen ATP ATP is also involvedis also involved

NADPNADP

Starting Compound and rubisco

CO2

H NADP truck

+

+

+

ATP’s

Sugar and Starch

Don’t forget:

Sunlight Energy to

Chemical Energy to

ATP’s in living things to

movement, repair and transport to (Bio Work) to

Heat Energy

Chloroplast

Mitochondrion

Mr. G

Food

All living things depend upon the sun for energy directly and indirectly.