Part One:

 The Light Dependent Reaction

not all wavelengths of light are utilized the same during photosynthesis.
   which wavelengths of light are best utilized by photosynthetic organisms to carry out photosynthesis?

 each glucose
​ has 6 carbons

from glycolysis...

    what is NADH?

          NADH
        is used during
   cellular respiration

    CO2 provides Carbon and Oxygen

the buttons below  link to several tutorials that will be of help as you explore this information

        let's chat mitochondria...

2. the energy that's stored in the bonds of glucose is released and that energy is used to assemble ATP during cellular respiration .

             ​CO2 and H2O are 
used during photosynthesis

  the light independent reaction (Calvin cycle) cranks through 3              carbons (CO2) at a time...
   two turns of the crank yields   two halves of a glucose, 3C each

​    steps of aerobic cellular respiration 

what is a chloroplast?

       photosynthesis takes place in two parts:
1. the light dependent reaction
2. the light independent reaction (also called the Calvin cycle and in the olden
    days was called the dark reaction)

            ATP​   
​ provides energy

                                    Part Two:
  The light Independent Reaction

      each turn of the crank produces
1/2 glucose molecule (1 G3P w/ 3C)
​so 2 turns produce one glucose (w/ 6C)

  NADH is an intermediate energy carrier...
​  when NAD --> NADH it has been reduced
  when NADH --> NAD it has been oxidized
NADH carries Hydrogen released from the breakdown of the glucose molecule to the electron transport chain. 

  Part II: Photosynthesis

endergonic reaction:
energy is required as input by the ​reaction

the laws of thermodynamics describe
​energy exchange

1. light dependent reaction:
  sunlight energy is captured
 1. ATP is assembled
 2. NADPH is assembled 
     using H2O as H donator
 3. O2 is released  

 2. the energy released during these redox exchanges from receptor to receptor is used to push H+ from the lumen across the inner membrane of the mitochondria into the intermembrane space. now there is a chemical gradient of H+
across this membrane. 

   ​Step One:       Glycolysis

 G3P (3C) is modified to
become pyruvate (3) 

 chemiosmosis
is the movement of ions (like the proton H+)
​ across a membrane resulting in an electrochemical gradient that drives ATP production...

basically moving a whole lot of H+ to one side of the membrane then allowing the H+ to only get back to the other side of the membrane via an enzyme that assembles ATP.

The light energy  is  passed from chlorophyll molecule to chlorophyll molecule until it reaches the reaction center where this light energy
boosts an electron to a high energy level. 

this is the photosystem II with its reaction center

chloroplasts and mitochondria have their
own DNA!
remember endosymbiosis?!

remember, each glucose produces 2 pyruvates so the transition of a pyruvate into the mitochondria happens twice for each glucose 

                 Step Three:
 Electron Transport Chain                     ​(ETC)

CoA (coenzyme A) is a transporter for the 2C acetyl group.
It brings the acetyl group to the
​ "right place"
in the Kreb cycle.

  during the Kreb cycle
    the 2C acetyl groups from glycolysis/transtion         reaction are broken down (exergonic rx)
                 
    C, H, O, and energy are released.
      the C and O are released as CO2 gas.
          the H bonds to NAD (reduces NAD to NADH)

in this way, the exergonic release of energy from C6H12O6 being broken down is coupled with the endergonic reactions that assemble NADH. 
​
 NADH transfers this energy and H to the Electron Transport Chain (ETC)

what happens when this circle of life is disrupted?

potential (stored) energy
vs
kinetic (released)  energy 

The human body isn't 100% efficient at converting chemical energy into action. We run at about 25% efficiency. Still, we're better than most cars which run at about 20% efficiency. As a producer, a cornfield in Iowa shows a 1.5% efficiency when converting sunlight into chemical energy. 

                 what are the reactants for the light dependent reaction?
                  what are the products of the light dependent reaction?
   which of these products are used during the light independent reaction                                            and what is their specific function?

                               so in glycolysis
           each molecule of glucose (6C) 
​  yields two molecules of pyruvate  (3C each)

      2. light independent                                  reaction:
 1. the energy from ATP
 2. the H from NADPH
 3. 6 CO2 are used to assemble
           glucose =

okay, so...
​1.  the sun's energy is used to bond C, H and O  together to make glucose (C6H12O6) during photosynthesis.

  both are
energy and hydrogen carriers

how is the structure of the chloroplast
​compared to that of the mitochondria?

  what are the reactants for the       light independent reaction?

       what are the products?

so, inphotosynthesis,
bonds form between the atoms
of C, H and O to make glucose,
converting the light energy
to chemical energy.

​ 1. glycolysis (occurs into the cytoplasm)
 2. Krebs cycle (after transitioning into                                  the mitochondria)
 ​3. electron transport chain 

 H2O is used during the light dependent rx

 CO2 is used during the light              independent rx

btw...specifics re numbers of H and their movement across the mitochondrial inner membrane...

how does this molecular machine called
 ATP synthase 
really work?

  btw...
​glycolysis
   for real...

 each pyruvate has 3 carbons

            the two acetyl molecules are broken down creating CO2 and H2O. the energy from
these reactions are used to assemble NADH. 

4. the last receptor for the electron along this chain is oxygen. The hydrogen that has been transferred along the series of protein receptors
bonds to oxygen, forming water.
​water is a byproduct of aerobic cellular respiration. 

            Step Two:
   The Kreb Cycle

exergonic reaction:
energy is released
​ by the reaction 

3. this gradient causes the H+ to move back into the lumen via ATP synthase, a molecular machine which assembles ATP from ADP and P using mechanical energy. 

               what is light?

        NADPH
   is used during 
  photosynthesis

during the ETC...
 1. NADH donates energy when NADH is oxidized 
(= a Hydrogen is removed). The Hydrogen that is removed
is transferred via oxidation/reduction reactions along a series of protein receptors imbedded in the inner membrane of the mitochondria.
Remember, this Hydrogen was bonded to NAD when it was removed from glucose as glucose was broken down so it carries with it the energy from those
exergonic reactions. 

                     NAD                                      NADH

what is chemiosmotic phosphorylation...
​                    whew! that's a lot!

2 pyruvates =
product

                           After glycolysis,
    the 2 pyruvates made during glycolysis
   transition into the mitochondria
                     from the cytoplasm.
 One Carbon is removed (along with H and O) 
from each 3 Carbon pyruvate producing:
 1.  two, 2 Carbon acteyl molecules which         move into the mitochondria as acetyl CoA
 2. two CO2 which are released as waste gas
3. NADH which carries energy & H to the ETC

2. a quantum of electromagnetic radiation ​ is called a photon. Photons carry kinetic  energy but is a massless particle of light. 

1. electromagnetic radiation
​is the flow of energy at the speed of light. This takes place in the form of the electric/magnetic fields
waves such as radio waves, visible             light, and gamma rays.            

      NADPH
​    provides H

     transitioning from glycolysis to the Kreb cycle

like a currency exchange...

 this is one thylakoid 

what "pushes"  the H+ across the membrane?
The energy released from NADH being "oxodized" (losing H) to become  of NAD + H.

                     (glucose) and O2 are produced during photosynthesis

and this chemical energy in glucose is transferred to the bonds of ATP
during cellular respiration
forming  chemical energy that can be used by cells to perform work.

 Each thylakoid is a site
​  for photosynthesis

                    Cellular Respiration
​ energy from the break down of glucose is used to assemble ATP

3. photons travel in waves. photon energy is inversely proportional to the wavelength of the electromagnetic wave. The shorter the wavelength, the more energetic is the photon, the longer the wavelength, the less energetic is the photon.

G3P = 
glyceraldehyde 3-phosphate 

 playing hot potato..     ​  and the ETC

3. potential chemical energy of ATP
fuels cellular activites via the relsease of kinetic energy as ATP is degraded back to ADP and P 

1 glucose =
reactant

    endosymbiotic theory

this is is a chloroplast.
inside are multiple thylakoids stacked like pancakes

light energy is captured by photosystems which are complex membrane proteins that contain chlorophyll.

      what is chlorophyll??

1. kinetic light energy converted to potential chemical energy by assembling glucose from CO2 and H20

watch these videos...
they show how this enzyme works to assemble ATP using the energy from the H+ gradient. they're terrific!

  Kreb cycle
   for real...

   The Mechanics of Energy Exchange

The high-energy electron is passed to a series of receptor molecules imbedded in the membrane. As it releases its energy during these redox reactions, this energy is used to push H+ across the membrane resulting in a concentration gradient. the H+ in this gradient move through ATP synthase which uses this energy to assemble ATP. the electron boosted from the the reaction center is replaced with an electron from the splitting of water. The hydrogen proton from this water split joins with the electron  that has travelled down the chain of receptors as it moves to its last receptor which is NADP forming NADPH. Oxygen gas is released as a waste product. 

Sunlight energy is kinetic energy because light waves are constantly in motion and can be absorbed.

wait...what's NADPH??
​ we just learned about NADH

2. potential
 chemical energy in the glucose bonds is transferred into the potential chemical energy
of cells by bonding ADP and P ​to form ATP

​what's ATP??