Welcome to Dr. Kate Brilakis' Learning Portal

Pi and NAD needed for the oxidation of G3P
G3P is phosphorylated to increase its energy and decrease its stability.
​NAD are reduced to form NADH 

since pyruvate is a charged molecule,
it can only cross the mitochiondrial membranes via active transport using the transport protein pyruvate translocase. 

   the 2 pyruvates made during glycolysis
   transition into the mitochondria
from the cytoplasm.

 chemiosmosis
is the movement of ions 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.

ADP is phosphorylated forming more 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?!

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

how does this AMAZING molecular machine called
 ATP synthase 
really work?

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

               what is light?

      NADPH
​    provides H

 cellular respiration ​step 3
the citric acid cycle

1 glucose =
reactant

is that it??  ​well....​not so fast

+ 2 ATP

      what is chlorophyll??

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

cellular respiration
potential chemical energy in the bonds of glucose is transferred to the potential chemical energy
of ATP

+ 2 ATP

       photosynthesis takes place in two parts

            ATP​   
​ provides energy

                                    Part Two:
  The light Independent Reaction

  what are the reactants for the       light independent reaction?

       what are the products?

               enter the      endosymbiotic theory

step  1.
​glycolysis
 (occurs into the cytoplasm)

plus 2 ATP  and   2 NADH

                lets look at some of the whys...

                     NAD                                      NADH

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 

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

   The Mechanics of Energy Exchange

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

​what's ATP??

2. the energy stored in the bonds of glucose is released then used to assemble ATP during
​cellular respiration

  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

 each glucose has 6 carbons

 when we describe the process of   cellular respiration, we generally partitian the   process into three steps...

  during the citric acid cycle
    the 2C acetyl groups from the transition reaction
          are broken down               
    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 the hydrolysis of glucose is coupled with endergonic reactions assembling NADH. 

 NADH transfers this energy/electrons to the
​Electron Transport Chain (ETC)

what happens when this circle of life is disrupted?

potential (stored) energy
vs
kinetic (released)  energy 

  both are
energy/electron
​carriers

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

 Each thylakoid is a site
​  for photosynthesis

                    Cellular Respiration
  energy released by the catabolism of glucose is used to assemble our
                                       cell's energy currency... ATP

carbon, hydrogen and oxygen in ----> carbon, hydrogen and oxygen out

the transition between glycolysis and the
citric acid cycle occurs in the mitochondria 

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. 

the laws of thermodynamics describe ​energy exchange

          NADH
        is used during
   cellular respiration

 2. the electrons are transferred via                     oxidation/reduction reactions along a           series of protein receptors imbedded in       the inner membrane of the
     mitochondria.

- 2 ADP

               let's review   
​           
mitochondria

 cellular respiration ​step 4
the electron transport chain (ETC)

NAD+ carries the electrons of a hydride
(a hydrogen atom with an extra electron = anion) 
from one region of a cell to another
like an electron shuttle service.
When NAD is reduced it = NADH
when NADH is oxidized = NAD
NADH carries electrons to the electron transport chain. 

                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 

glucose has a phosphate added and ATP is dephosphorylated

1. glucose-6-phosphate is more reactive than glucose
2. adding phosphate prevents glucose from exiting the cell

  5. the last receptor for the electron along             the ETC is oxygen. The electron that has
       been transferred along the series of
       protein receptors bonds to oxygen with
       its H+ forming water.

here's the balance sheet...

exergonic reaction:
energy is released
​ by the reaction 

     C, H and O are removed from the 2 
                  pyruvates producing...

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.            

H + OH are cleaved forming water

 its like playing hot potato! 

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

photosynthesis
​ kinetic 
light energy is  converted to potential chemical energy by assembling glucose

- 2 ADP

end with

2 pyruvate 3C each = 6C

  Part II: Photosynthesis

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

the citric acid cycle
or
the Kreb cycle (Dr. Hans Krebs)
or
the tricarboxylic acid cycle

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  

  3. the energy released during these redox
       exchanges from receptor to receptor             is used to move H+ from the lumen                 across the inner membrane of the                   mitochondria into the intermembrane           space, creating a chemical 
gradient. 

glucose modified to fructose
then fructose is phosphorylated so it is unstable and can be split in half

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?

+ 2 NADH

        NADPH
   is used during 
  photosynthesis

               during the ETC...
 1. NADH donates energy/electrons when         NADH is oxidized (hydrogen is removed)

2 pyruvates =
product

start with
1 glucose = 6C

where does
photosynthesis occur in plants?
 

                      Part One:

 The Light Dependent Reaction

step ​3.
​ETC
electron transport chain 

 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?
 

  1.    2 x acetyl molecules (2 C each) which 
           move into the mitochondria as
                          acetyl CoA

  2.      2 x CO2 molecules which are
               released as waste gas

 3.       2 x NADH which carry                                             carrying electrons to the ETC

 each glucose
​ has 6 carbons

 cellular respiration ​step 2
the transition reaction 

       is ATP the only energy carrier? nope!
       let's chat NADH?

step 2.
Krebs (TCA) cycle
 
(after transitioning into 
     the mitochondria)

 cellular respiration ​step 1            Glycolysis

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

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

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

 each pyruvate has 3 carbons

we'll explore mtDNA
during genetics