Photosynthesis

All organisms require energy to carry out their life processes. Active transport Cell division Movement Production of proteins

The sun is the ultimate energy source for these life processes.

OBTAINING ENERGY

Autotrophs/producers-use (light) energy directly from the sun to make their own food and other organic molecules necessary for life

Heterotrophs/consumer-obtain energy from eating other organisms (from the sun indirectly)

INTRO TO PHOTOSYNTHESIS

Process that converts light energy from the sun into usable chemical energy (glucose).

Complex series of reactions in which the products of one reaction are consumed as the reactants in the next reaction.

INTRO TO PHOTOSYNTHESIS

Occurs in plants and some algae inside of chloroplasts

Requirements: Reactants:Light energy from the sun, water,

carbon dioxide Chlorophyll Enzymes

PHOTOSYNTHESIS: THE CHEMICAL EQUATION

6CO2+ 6H2O + LIGHT ENERGY → C6H12O6 + 6O2

OR carbon dioxide + water + sunlight → glucose + oxygen

PHOTOSYNTHESIS: THE 2 STEPS1. Light reaction (Light-dependent reaction)

- First step of photosynthesis that traps sunlight and makes NADPH and ATP to run the dark reaction

PHOTOSYNTHESIS: THE 2 STEPS2. Dark reaction (Light-independent reaction

or the Calvin Cycle)- Second step of photosynthesis that uses

ATP and NADPH from the light reaction and carbon dioxide from the air to make glucose

LIGHT REACTION

Requires: H2OADPNADP+

Produces:O2

ATPNADPH

*ATP and NADPH store energy

Where sunlight is used.

CALVIN CYCLE (LIGHT INDEPENDENT REACTION)

Requires: CO2

ATP NADPH

Produces: Organic

Compounds ADP NADP+

Converts CO2 from the air into usable chemical energy (glucose).

PHOTOSYNTHESIS: STRUCTURE OF THE CHLOROPLAST

Stroma: Space inside the chloroplast

CHLOROPLAST STRUCTURE

Thylakoids: green contain chlorophyll; where the light reactions occurStroma: liquid portion of chloroplast; where the Calvin cycle occursChlorophyll: green pigment in plants that absorbs light energyPigment: light-absorbing compound

Photosynthesis Reactions 6CO2+ 6H2O + LIGHT ENERGY → C6H12O6 + 6O2

OR carbon dioxide + water + sunlight → glucose + oxygen

Light Dependent ReactionOccurs in the thylakoidsChlorophyll traps light energyThis makes energized electrons that go on to the electron transport chain

Uses H2O → → Produces O2

Electron Transport Chain (ETC)

oEnergized electrons move down the ETCoProduces energized carriers, ATP and NADPH, that capture & store energy

Light Independent Reaction aka Calvin Cycle

oOccurs in the stromaoUses energy from ATP & NADPH

Depleted Carrierso ADP & NADP (from ATP & NADPH) have to be recharged by sunlight

Produces Glucose

Uses CO2 & H2O

Chloroplast

FACTORS AFFECTING PHOTOSYNTHESIS Light intensity Carbon dioxide availability Temperature