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Respiration and Fermentation
CHAPTER 6
REVIEW
Redox reaction of compounds.
Xe + Y
X + Ye
(e=electron)
Glucose (sugar) provides energy. Monosaccharides and Dissacharides structures usually give
quick energy. Polysaccharide structure is mainly used for storage and structure. Glucose is
obtained from and/or produced by plants
The Cell and the Mitochondria
Special Electron Carriers
NAD+ = Nicotinamide Adenine Dinucleotide (figure, page 115)
FAD = Flavin Adenine Dinucleotide
They will get reduced to transfer energy for useful work.
Cellular respiration has three main steps
-Glycolysis
-The Krebs cycle
-The Electron Transport Chain
Glycolysis
Where does this step occur? _______________________________
A- Energy investment steps
Cells uses 2 ATP to phosphorylate the intermediate of glycolysis
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B- Energy pay-off steps
Two 3 carbon intermediates are oxidized
4 ATPs are produced
Total of 10 steps which 5 are preparatory (investment phase).
STEP 1 Glucose Æ Glucose-6-Phosphate (G-6P)
STEP 2 G-6P Æ Fructose-6-Phosphate (F-6P)
STEP 3 F-6P Æ Fructose-1,6-bisPhosphate (F-1,6BP
(enzyme involved: phosphofructokinase, committed step)
STEP 4 F1,6bP Æ GlycerAldehyde Phosphate (GAP)
and DiHydroxyAcetone phosphate (DHAP)
STEP 5 DHAP Æ GAP (Conversion of isomers)
STEP 6 GAP Æ1,3 DiPhosphoGlycerate (1,3DPG)
STEP 7 1,3DPG Æ 3 PhosphoGlycerate (3PG)
STEP 8 3PG Æ 2 PhosphoGlycerate (2PG)
STEP 9 2PG Æ PhosphoEnolPyruvate (PEP)
STEP 10 PEP Æ Pyruvate
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Transition between Glycolysis and Krebcycle
Where does this occur?
Pyruvate is converted to Acetyl CoA
CO2 CoASH
Pyruvate
NAD+
Acetyl-CoA (or CoASH, very reactive)
NADH
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Krebs cycle
Where does the Krebs cycle steps occur?
__________________________
Acetyl CoA enter the MATRIX
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Acetyl-CoASH
CoASH
Oxaloacetate
Citrate
NADH
NAD+
Isocitrate
malate
NAD+
CO2
NADH
άketoglutaric
Acid
Fumarate
CO2
FADH2
NAD+
Succinyl CoA
Succinate
FAD
NADH
GTP
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GDP
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Electron Transport chain
Electron carrier molecules embedded in the inner mitochondrial membrane
NADH
Transfer to Flavoproteins (FMN)-Flavin Mononucleotide
Fe - S
FADH2
Fe-S
Ubiquinone Q
Cytochrome =b, c1,c,a,a3
Oxygen
H2O
What happens in Anaerobic conditions? (Anaerobic =An-aerobic=no air)
What happens to the truckload of NADH and FADH2 molecules?
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Pyruvate enters fermentation:
Pyruvate
Ethanol
Pyruvate
Lactate
Versatility of Catabolism
Respiration can oxidize organic molecules other than glucose.
For example: monosaccharide, dissacharides, proteins and fats.
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