CH339K: Biochemistry 1
Fall 2013
Dr. Ready
What's covered on Exam 3
This sheet is to give you a concrete idea of what I expect you to know. As always, it is intended as a study guide
and not as an exhaustive list of topics covered nor as an answer key.
Introduction to Metabolism (Chapter 12)
Read it if it helps
Glycolysis and associated stuff (Chapter 13)
Glycolytic pathway:
Location
Reactions
Enzymes
Net Products
Regulation at phosphofructokinase and pyruvate kinase steps
What if you don't have O2?
Lactic acid fermentation / lactate dehydrogenase
Ethanol fermentation / pyruvate decarboxylase and
alcohol dehydrogenase
Glycogen metabolism
Glycogen phosphorylase a and b: regulation by
phosphorylase kinase,
phosphorylase phosphatase
Debranching enzymes for amylose and glycogen
The Krebs' cycle and stuff (Chapter 14)
Oxidation of pyruvate by pyruvate dehydrogenase
Location
Big 3-enzyme complex
Pyruvate Dehydrogenase Proper / Thiamine Pyrophosphate
Dihydrolipoamide Transacetylase / Lipoic Acid
Dihydrolipoamide Dehydrogenase / FAD
Pyruvate + NAD+ + HSCoA --> CO2 + NADH + AcCoA
Krebs' / Citric acid / Tricarboxylic acid cycle
Location
Reactions
Enzymes
Net Products
Anaplerotic reactions
Pyruvate carboxylase
PEP carboxylase
Malate dehydrogenase
Glutamate dehydrogenase
-Oxidation of fatty acids (Chapter 18)
Liposome Activation
Blood transport by Serum Albumin
Activation: fatty acyl - CoA ligases
Transfer to mitochondria: linkage to carnitine
-Oxidation
Location
Net Products
Odd-number fatty acids
Processing of propionyl-CoA
Unsaturated fatty acids
Enoyl CoA Reductase (2 double bonds to 1)
Enoyl CoA Isomerase (cis-3,4 to trans-1,2)
Activation of Glycerol
Electron Transport (Chapter 15)
Standard reduction potentials: Eo'
Predicting the direction of a redox reaction
Real vs standard reduction potentials
E'  E' o 
RT  [Oxidant] 
ln 

nF  [Reductant ] 
Free energy, equilibrium constants and the reduction potential
G o '  -nFE' o
Keq  exp(
nF
E' o)
RT
The electron transport chain:
Location
Pathway
NADH dehydrogenase (Complex I)
Coenzyme Q
Succinate dehydrogenase (Complex II)
Coenzyme Q - cytochrome C reductase (Complex III)
Cytochrome C
Cytochrome Oxidase (Complex IV)
Electron carriers
FMN, Coenzyme Q, heme, FeS complexes
Action - generating proton gradient
ATP Synthase: F0/F1 ATPase
Chemiosmotic coupling
3-state model of activity: L/T/O conformations
Anabolic Pathways:
Glyoxylate cycle (Chapter 14)
Net synthesis of oxaloacetate from AcCoA
Oxaloacetate can be used in gluconeogenesis
'Short-circuited' Krebs' cycle
Reactions
Products
Gluconeogenesis (Chapter 16)
Reversal of glycolysis except for:
Glucose + ATP
G-6-P + ADP
F-6-P + ATP
F-1,6-bisP + ADP
PEP + ADP
Pyruvate + ATP
PEP formation via:
Pyruvate carboxylase to
OAA to
Phosphoenolpyruvate carboxykinase (PEPCK)
Cost in NTPs?
F-6-P formation via fructose-1,6-bisphosphatase
Glc formation via glucose-6-phosphatase
Remaining rxns driven by mass action
Substrates
lactate
pyruvate
alanine
oxaloacetate
other aa's
oxaloacetate (except leu, lys)
glycerol
glycerol-3-P
dihydroxyacetone phosphate
propionate + CO2
methylmalonyl-CoA
succinyl-CoA
Regulation by fructose-2,6-bisphosphate
Cori cycleLactose formation favored in NADH - rich tissues
Lactose transported to liver in bloodstream
Reconversion to pyruvate / gluconeogenesis favored in NAD+ rich liver
Glucose transported to tissues in bloodstream