Cellular Respiration and Fermentation
By: Venidikt • Essay • 595 Words • April 23, 2010 • 1,576 Views
Cellular Respiration and Fermentation
Cellular Respiration and Fermentation
Facts to Remember
1. Cellular respiration is a catabolic series of reactions.
2. All living forms conduct some form of cellular respiration, either aerobic or anaerobic.
a. Aerobic is in the presence of oxygen
b. Anaerobic is in the absence of oxygen or none oxygen requiring.
3. The starting molecules consist of the biological molecules with carbohydrates (monosaccharides) as the first choice. The order of use is given below.
a. Carbohydrates
b. Lipids„іacetyl CoA (via beta oxidation)„і enters Krebs at the start site
c. Proteins„іamino acids-„і enters glycolysis, transitional step or Krebs (point of entry is determine the carbon chain)
d. Nucleotides„іfive carbon sugars„і six carbon sugars
4. Cellular respiration and fermentation produce energy in the form of ATP and key intermediates needed for anabolic reactions.
5. Cellular respiration and fermentation are redox reactions.
Aerobic Respiration
Model: Eukaryote Cell
Locations: cytoplasm, matrix of mitochondrion, inner mitochondrial membrane
Starting Molecules: Glucose (monosaccharide), 2 ATP, oxygen, and 2 NAD+
End Products: 38-40 ATP, CO2, H20, FAD+ and NAD+ (from FADH2 and 2 NADH + H+ via electron transport)
Step I: Glycolysis (an anaerobic process)
Important steps are sited, please see textbook for full explanation.
1. Glucose to glucose-6-phosphate: 1 ATP energy input
2. Fructose-6-phosphate to fructose 1,6, bis-phosphofructose: Committal Step
a. Under allosteric regulation
b. Allosteric modulators: ATP and Citrate
c. Determines whether glycolysis will continue
d. 1 ATP energy input
3. Fructose 1,6 bisphosphate is cleaved to form dihydroxyacetone phosphate (DAP) and glyceraldehydes 3 phosphate (G3P).
a. Cell prefers G3P, thus will ultimately convert DAP to G3P. Thus all reactions series from this point must be counted twice, once for G3P and secondly for DAP, after conversion.
4. G3P to 1,3 bis-phosphoglycerate
a. An inorganic phosphate is used
b. NAD+ „і NADH + H+: a potential for ATP production in ETC
5. 1,3 bis- phosphoglycerate „і3 phosphoglycerate
a. ADP „іATP: Method is substrate-level-phosphorylation (SLP)
6. 3-phosphoglycerate„і„іphosphoenol pyruvate
7. Phosphoenol pyruvate„іpyruvate + 1 ATP(via SLP)
8. Special Note: Pyruvate enters the matrix of mitochondrion
Glycolysis is over and has produced 4 ATP + 2 pyruvate + 2 NADH + H+
Step II: Transitional
Location: matrix of mitochondrion
Starting molecules: 2 pyruvate + 2 NAD+
End Products: 2 Acetyl CoA + 2 NADH+H+ + 2 CO2
Special Note: Acetyl CoA enters Krebs
Step III: Krebs Cycle
Location: Matrix of the Mitochondrion
Starting