-plants and algae make their own food via this :

-most food chains start with ____synthesizers

-an energy transforming reaction.

-Solar energy is transformed into chemical energy

During photosynthesis this is utilized and oxygen is released.

-Is picked from the atmosphere by plants.

-the oxygen released is used by organisms and undergo aerobic respiration.

-this oxygen is also important in maintenance of the ozone layer.

-Excess CO_2 is poisonous to animals.

-Excess CO_2 contributes to global warming.

-our atmosphere consists of 79% nitrogen, 20% oxygen, and 1% other gasses.

-T_H_I_S falls into this "other gas" group and compromises only 0.039% of the total atmosphere.

-CO_2 gas enters the leaf through stomates.

6CO_2 + 12H_2_0 ---SUN---> C6 H_12_0_6 + 6H_2_0 + 60_2

CO_2 +H_2_0 ---SUN---> C H_2_0 + 0_2

described in terms of

-its energy content

-its wavelength

The light energy is packaged in this.

-Are discrete packets of radiant energy that travel in waves.

-is measured on what we call electromagnetic spectrum.

-Electromagnetic Spectrum is the range if types of solar radiation based on wavelength.

-The electrmagnetic spectrum is divided on the basis of wavelengths.

-gamma rays have the shortest wavelength

-radio waves have the longest wavelength

-Gamma rays are very energetic

-they disrupt or destroy the biological molecules they strike.

-Radio waves are very low in energy.

-This is just a small portion of the electromagnetic spectrum

-Is the full range of electrmagnetic radiation in the universe.

-Radiation ranges from highly energetic gamma rays to very low energy radio waves.

-The photons of visible light have wavelength in the narrow range of 380nm (violet light) to 750 nm (red light)

-Living things can absorb and use light within 380nm-750nm.

-photosynthetic pigments use primarily the visible light portion of the electrmagnetic spectrum.

-The ozone layer filters, CO_2 and water vapor filters out solar radiation.

-Only 42% of the solar radiation reaches the earth surface.

- Two major : _____

-Chlorophyll a

-Chlorophyll b

-Both chlorphyll a and b absorb violet blue and red wavelength.

-Very little green is absorbed, the rest is reflected back.

-80% of visible light is absorbed, the rest is reflected back.

-other plant pigments

-These are yellow-oragne pigments which absorb light in

:violet : blue : green

-In the spring, ____ a nd b are active.

-In the fall, chlorophyll in leaves breaks down and carotenoids pigments show through.

-Light trapping and sugar building reactions of photosynthesis occur in the chloroplasts.

-Each corn leaf cell may contain 40-50 chloroplasts.

-Each square millimeter of a leaf surface may contain more than 500,000 chloroplasts.

-Chlorophyll and other pigments involved in absorption of solar energy are embedded within this:

-the pigments absorb solar energy

-CO_2 is reduced in the stroma to produce CH_2_0

-Light - dependent reactions occur in :this:

-Light independent reactions occur in the stroma.

-The stroma contains enzyme -rich solution that reduces CO_2 converting it to an organic compound.

- The two sets of reactions were proposed by f.f. blackman in 1905

:light-dependent reactions

:light-indepentdent reactions

Light -dependent reactions occur in the thylakoid membranes because chlorophyll is embedded within the TM

-Light independent occur in the stroma

-Light -dependent reactions require participation of two light gathering units :Photosystem I (PSI)

:Photosystem II (PSII)

a photosynthetic unit made of

:a pigment complex

:electron acceptor

-Each photosystem has a reaction center

-Chlorophyll a is the reaction center

-When solar energy is absorbed high - energy electrons are generated .

Made of three things:

-Chlorophyll a molecule

-Chlorphyll b molecule

-orange and yellow accessory pigments

Electron pathways

Electrons have two pathways:

-cyclic electron pathway

-noncyclic electron pathway

-ATP is generatedduring this.

-ATP- Adenosine Triphosphate

-PS I (only) is involved in this

-high energy electrons leave PS I reaction to center to electron acceptor and back to the reaction center.

-before electrons return to the reaction center, they travel down an electron transport system (ETS)

-ETS is a series of carriers that pass electrons from one carrier to the next

-ATP is the molecule that is generated in the process.

NON-Cyclic Electron Pathway

-ATP and NADPH molecules are generated during this

-both PS I and PS II are involved in this

-High energy electrons leave PSI reaction center to electron acceptor and DO NOT return back to the reaction center.