1. Metabolism cont’d

2. Carbohydrate Catabolism

3. Carbohydrate Catabolism cont’d

4. Summary of Carbohydrate Catabolism

5. TCA Cycle (Krebs Cycle)
2 acetyl-CoA groups are oxidized in the Krebs cycle for each glucose molecule (1 six-carbon glucose is oxidized to two 3 carbon pyruvic acid molecules, each of which is decarboxylated to produce an acetyl-CoA molecule). 
Electrons are picked up by NAD+ and FAD for the electron transport chain.
From one molecule of glucose, oxidation in the Krebs cycle produces 6 molecules of NADH, 2 molecules of FADH2, and 2 molecules of ATP.
Decarboxylation produces 6 molecules of CO2.

6. TCA Cycle (Krebs Cycle)

7. Electron Transport Chain
As electrons are passed from carrier to carrier in the chain, they decrease in energy and some of the energy lost is harnessed to make ATP

8. Summary
In aerobic prokaryotes, 38 ATP molecules can be produced form complete oxidation of a glucose molecule in glycolysis, the Krebs cycle, and the electron transport chain.
In eukaryotes, 36 or 38 ATP molecules are produced from complete oxidation of a glucose molecule (in some tissues 2 ATP are required to shuttle the 2 electrons from the NADH produced in glycolysis across the mitochondrial membrane to the electron transport chain, in others there is no energy cost and 38 ATP are gained per mole of glucose).

9. Summary of Respiration
Aerobic respiration: The final electron acceptor in the electron transport chain is molecular oxygen O2
Anaerobic respiration: The final electron acceptor in the electron transport chain is not O2. Yields less energy than aerobic respiration because only part of the Krebs cycle operates under anaerobic condition

10. Anaerobic Respiration
Electron acceptors other than oxygen are used i.e.:
Inorganic oxygen containing molecules such as Nitrate (NO3-), Sulfate (SO42-), Ferric iron (FE3+), Carbonate (CO32-) and Perchlorate (ClO4-)
Less energy is released
Permits microorganisms to respire in anoxic environments

11. Fermentation Any spoilage of food by microorganisms (general use)
Any process that produces alcoholic beverages or acidic dairy products (general use)
Any large scale microbial process occurring with or without air (common definition used in industry)

12. Fermentation cont’d Scientific definition
Release of energy from organic molecules
Does not require oxygen
Does not use the Krebs cycle of Electron transport chain
Uses organic molecule as the final electron acceptor

14. Types of Fermentation

16. Fermentations By Naturally-Occurring Organisms
PRODUCT
APPLICATION
ORGANISM
Bacitracin
Antiobiotic
Bacillus subtilis (bacterium)
Chloramphenicol
Streptomyces venezuelae (bacterium)
Citric acid
Food flavoring
Aspergillus niger (fungus)
Erythromycin
Antibiotic
Streptomyces erythaeus (bacterium)
Invertase
Candy
Saccharomyces cerevisiae (fungi)
Lactase
Digestive aid
Escherichia coli (bacterium)
Neomycin
Streptomyces fradiae (bacterium)
Pectinase
Fruit juice
Penicillin
Penicillium notatum (fungus)
Riboflavin
Vitamin
Ashbya gossypii (fungus)
Streptomycin
Streptomyces griseus (bacterium)
Subtilisins
Laundry detergent
Tetracycline
Streptomyces aureofaciens (bacterium)

17. Fermentations By Genetically Engineered Organisms
PRODUCT
APPLICATION
ORGANISM
B. growth hormone
Milk production(cows)
Escherichia coli (E. coli)
Cellulase
Cellulose
E. coli
H. growth hormone
Growth deficiencies
E.coli
Human insulin
Diabetics
Monoclonal antibodies
Therapeutics
Mammalian cell culture
Ice-minus
Prevents ice on plants
Pseudomonas syringae
Sno-max
Makes snow
t-PA
Blood clots
Tumor necrosis factor
Dissolves tumor cells

18. Fermentation Alcohol fermentation: Produces ethanol and CO2
Lactic acid fermentation: Produces lactic acid
-homolactic fermentation: Produces lactic acid only
-heterolactic fermentation: Produces lactic acid and other compounds

19. Final Electron Acceptor
Electron carriers
Final electron acceptor
Oxygen O2
Aerobic respiration
Other inorganic molecules
(NO3-), (SO42), (FE3+), (CO32-) & (ClO4-) Anaerobic respiration
Organic molecules
Pyruvic acid
Fermentation