Post on 21-Dec-2015
Inputs Outputs Location in the Cell
Glycolysis Glucose, ADP + PNAD+ + H+ ATP
2 Pyruvate , ATPNADHADP + P
Cytoplasm
Link Reaction 2 PyruvateNAD+ + H+
2 Acetyl – CoA, 2 CO2
NADH
Matrix of Mitochondria
Krebs Cycle 2 Acetyl – CoANAD+ + H+ FAD +2 H+
4 CO2
NADHFADH2
Matrix of Mitochondria
Oxidative Phosphorylation (ETC)
O2 + 2 H+ NADHFADH2
ADP + P
H2ONAD+ + H+ FAD +2 H+ *****ATP *****
Inner mitochondrial membrane and matrix of mitochondria
Light Dependent Reaction
H2ONADP+ + H+ ADP + P
O2 + 2 H+ NADPHATP
Inner thylakoid membrane and stroma of chloroplast
Calvin Cycle (Carbon Reactions, Light Independent Rxn)
CO2 NADPHATP
PGAL GlucoseNADP+ + H+ ADP + P
Stroma of chloroplast
Glycolysis (cytoplasm)
Pyruvate processing (membrane b/w
cytoplasm and mitochondria)/ Citric acid Cycle (mitochondrial matrix)
Electron Transport Chain (mitochondrial membrane)
Cellular Respiration Animationhttps://www.youtube.com/watch?v=-Gb
2EzF_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:KineticPotentialActivation
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.
DG = DH -
T* DS
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. EXERGONICIf DG is positive, addition of energy (work) is required for the reaction to proceed. ENDERGONICIf DG is zero, the system is in equilibrium.
Change in Gibbs free
energy
change in potential energyof the
system
change in the
disorderof the
system
We can use Gibbs free energy to predict when reactions are spontaneous :
Fig. 4.9
Coupled endergonic and exergonic reactions
Exergonic reaction Endergonic reaction
before
after
Gib
bs
free e
nerg
y overall DG
Almost every endergonic process performed by organisms is powered by the hydrolysis of ATP, including
C6H12O6 + 6 O2 6 CO2 + 6 H2O
Aerobic Cellular Respiration
36 ADP + 36 Pi 36 ATP
DG = –2870 kJ/mol
DG = +992 kJ/mol
DGtotal = -1878 kJ/mol
Inputs:
Outputs:
The Big Picture
Fig. 5.3
Fig. 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 Reactionshttp://www.science.smith.edu/departments/Biology/Bio
231/ltrxn.html
Calvin Cyclehttp://www.science.smith.edu/departments/Biology/Bio
231/calvin.html
Cellular Respiration Animations
Glycolysishttp://www.science.smith.edu/departments/Biology/Bio231/
glycolysis.html
Krebs Cyclehttp://www.science.smith.edu/departments/Biology/Bio231/kr
ebs.html
Electron Transport Chainhttp://www.science.smith.edu/departments/Biology/Bio231/et
c.html