Lecture 7 - Respiration
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Lecture 7 – Respiration Metabolism is built around anabolic pathways, and catabolic pathways. Catabolic is breaking things with lots of free energy down like carbohydrates, fats, and proteins into H 2 O, CO2 2 , and NH 3 . Catabolic Pathway -Delta G (Spontaneous/Exergonic) Anabolism +Delta G Endergonic Energy Coupling, ΔG = -3.9 kcal/mol ΔG = -3.9 kcal/mol A. Individual half- reactions B. Actual reaction mechanism
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Bio 1002
Transcript of Lecture 7 - Respiration
Lecture 7 – Respiration
Metabolism is built around anabolic pathways, and catabolic pathways. Catabolic is breaking things with lots of free energy down like carbohydrates, fats, and proteins into H2O, CO22, and NH3.
Catabolic Pathway -Delta G (Spontaneous/Exergonic)
Anabolism +Delta G Endergonic
Energy Coupling,
The addition of the phosphate results in a molecule which is much higher in free energy than glutamic acid.
B. Actual reaction mechanism
A. Individual half-reactions
ΔG = -3.9 kcal/mol
ΔG = -3.9 kcal/mol
Exergonic, Classic Catabolic
ATP
CO2
HHOH
H
H
HOOH
H
OH
CH2OH
O
Progress of reaction
Potential Energy
What you need to know.
Where is it found what does it do? What’s the start… the end? Free Energy? Requires O2
Where’s the Carbon? Not an accountant (Don’t worry about the crazy numbers). Compare and contrast to Photosynthesis.
Glycolysis (Breaking of Glucose)
You actually consume energy in the earlier stages of glycolysis. By putting the negatively charged phosphate on the glucose it makes it difficult to get into the cell or the ABC transporter it was made for. Free Energy goes down.
Pyruvate kinase has a binding site on the enzyme for the ADP and then the phosphate group gets transferred from the phosphate group to the ATP. Substrate-level Phosphorylation.
Matrix
Outer mitochondrial membrane
Inner mitochondrial membrane
Intermembrane space
This all evolved before eukaryotes, it all evolved in bacteria. The eukaryotes didn’t create photosynthesis OR respiration.
Cytosol Mitochondrial Matrix
Grey, CO2 because there’s no more free energy. Decarboxylation. NAD+ Becomes NADH. Acetyl CoA
There’s still free energy in the pyruvate (3 CH Bonds).
Two molecules to remember
Oxaloacetate Citrate
The complexity of the complexes is remarkable (Complex I, 40 genes).
Uncoupler allows for more ETC, the free energy in the proton gradient if it just leaks back through, the energy is just lost as heat. Potent uncoupler allows for protons to pass through the membrane. Why would dinitrophenol make you lose weight?
If there’s not enough oxygen, pyruvate will not go into the mitochondria and we end up synthesizing ethanol or lactate in the cytosol. **REDOX HOMEOSTASIS** NAD+ / NADH RATIO.
Causes pyruvate to stay in the cytosol.
