Inputs
Outputs
Location in the Cell
Glycolysis
Glucose, ADP + P
NAD+ + H+
ATP
2 Pyruvate , ATP
NADH
ADP + P
Cytoplasm
Link Reaction
2 Pyruvate
NAD+ + H+
2 Acetyl – CoA, 2 CO2
NADH
Matrix of
Mitochondria
Krebs Cycle
2 Acetyl – CoA
NAD+ + H+
FAD +2 H+
4 CO2
NADH
FADH2
Matrix of
Mitochondria
Oxidative
Phosphorylation
(ETC)
O2 + 2 H+
NADH
FADH2
ADP + P
H2O
NAD+ + H+
FAD +2 H+
*****ATP *****
Inner mitochondrial
membrane and
matrix of
mitochondria
Light Dependent
Reaction
H2O
NADP+ + H+
ADP + P
O2 + 2 H+
NADPH
ATP
Inner thylakoid
membrane and
stroma of chloroplast
PGAL  Glucose
NADP+ + H+
Stroma of chloroplast
Calvin Cycle (Carbon CO2
Reactions, Light
NADPH
Glycolysis (cytoplasm)
Pyruvate processing (membrane b/w cytoplasm and
mitochondria)/ Citric acid Cycle (mitochondrial matrix)
Electron Transport Chain
(mitochondrial membrane)
Cellular Respiration
Animation
https://www.youtube.com/watch?v=-Gb2EzF_XqA
Why do you suffocate when you lose access to oxygen?
a. Explain what happens inside your mitochondria when you
lose access to oxygen and why this poses such a dire
problem for your cells.
b. How is it that some other organisms don’t suffocate in
oxygen-free environments, and in fact thrive there?
Explain what the point of the “energy investment”
phase of Glycolysis is. Why put in ATP, if the cell
wants to get ATP out of it?
Metabolism
The totality of an organism’s chemical
processes.
Concerned with managing the material and
energy resources of the cell.
Catabolic Pathways
Pathways that break down complex molecules
into smaller ones, releasing energy.
Example: Respiration
Anabolic Pathways
Pathways that consume energy, building
complex molecules from smaller ones.
Example: Photosynthesis
Energy
Ability to do work.
The ability to rearrange a collection of matter.
Forms of energy:
Kinetic
Potential
Activation
Energy
Transformation
Governed by the Laws of Thermodynamics.
1st Law of
Thermodynamics
Energy can be transferred and transformed, but
it cannot be created or destroyed.
Also known as the law of “Conservation of
Energy”
2nd Law of
Thermodynamics
Each energy transfer or transformation
increases the entropy of the universe.
Entropy Measure of disorder
A
B
Summary
The quantity of energy in the
universe is constant, but its
quality is not.
Question?
How does Life go against
Entropy?
By using energy from the environment or
external sources (e.g. food, light).
Free Energy
The portion of a system's energy that can
perform work.
We can use Gibbs free energy to predict when reactions
are spontaneous :
DG = DH - T* DS
Change in
Gibbs free
energy
change in
potential
energy
of the system
change in the
disorder
of the system
Any reaction that decreases DG is thermodynamically favorable
and occurs spontaneously.
DGreaction = Gproducts - Greactants
If DG is negative, free energy is released and the reaction proceeds
spontaneously. EXERGONIC
If DG is positive, addition of energy (work) is required for the reaction to
proceed. ENDERGONIC
If DG is zero, the system is in equilibrium.
4.9
Coupled endergonic and exergonic reactions
before
Gibbs free energy
overall DG
after
Exergonic reaction
Endergonic reaction
Almost every endergonic
process performed by
organisms is powered by the
hydrolysis of ATP, including
Aerobic Cellular Respiration
Inputs:
C6H12O6 + 6 O2
36 ADP + 36 Pi
Outputs:
6 CO2 + 6 H2O
DG = –2870 kJ/mol
DG = +992 kJ/mol
DGtotal = -1878 kJ/mol
The Big Picture
5.3
5.4
All of the oxygen in Earth’s atmosphere was produced (and is continually
replenished) by photosynthesis. Explain why plants produce an excess of
oxygen.
a. Where is the oxygen that is released by photosynthesis coming from?
b. What do plants do with the sugar that is produced by photosynthesis?
c. Given that plants have mitochondria as well that engage in cellular respiration,
can you explain how there is still an excess of oxygen that gets released by the
plants?
Photosynthesis Animations
Light Dependent Reactions
http://www.science.smith.edu/departments/Biology/Bio231/ltrxn.html
Calvin Cycle
http://www.science.smith.edu/departments/Biology/Bio231/calvin.html
Cellular Respiration Animations
Glycolysis
http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html
Krebs Cycle
http://www.science.smith.edu/departments/Biology/Bio231/krebs.html
Electron Transport Chain
http://www.science.smith.edu/departments/Biology/Bio231/etc.html