1. Microbial Metabolism Ch 5
Metabolism is the sum of the chemical reactions in an organism.
Catabolism is the energy-releasing processes.
Anabolism is the energy-using processes. (typically building something)

2. Microbial Metabolism
Catabolism provides the building blocks and energy for anabolism.
Fig 5.1 know the relationships between these two processes and hot ATP binds them together
Figure 5.1

3. Amphibolic pathways
Are metabolic pathways that have both catabolic and anabolic functions.
This is basically all of life
Figure

4. Amphibolic pathways
Figure

5. Metabolic pathways are determined by enzymes.
A metabolic pathway is a sequence of enzymatically catalyzed chemical reactions in a cell.
A primary metabolic pathway are the reactions that do the basic work of the cell. Get food and grow
Metabolic pathways are determined by enzymes.
Enzymes are encoded by genes.
The purpose of this slide is to show the students that the metabolic pathways that an organism has directly correlates to its genome.

6. Biochemical tests Used to identify bacteria. Enzymes are genes
Sum of genes is your organism
Here is a graphic that shows how the metabolism of an organism can be used in a key to identify that organism.
Figure 10.8

7. Enzymes
Figure 5.2

8. Enzymes Biological catalysts Apoenzyme: protein
Specific for a chemical reaction; not used up in that reaction
Apoenzyme: protein
Cofactor: Nonprotein component
Coenzyme: Organic cofactor
Holoenzyme: Apoenzyme + cofactor

9. Enzymes
Figure 5.3

10. Important Coenzymes NAD+ NADP+ FAD Coenzyme A Biotin Folic acid
Many of the vitamins

11. Enzymes
The turnover number is generally 1-10,000 molecules per second.
Figure 5.4

12. Factors Influencing Enzyme Activity
Enzymes can be denatured by temperature and pH
Figure 5.6

13. Factors Influencing Enzyme Activity
Temperature
Figure 5.5a

14. Factors Influencing Enzyme ActivitypH
Figure 5.5b

15. Factors Influencing Enzyme Activity
Substrate concentration
Figure 5.5c

16. Factors Influencing Enzyme Activity
Competitive inhibition
Figure 5.7a, b

17. Factors Influencing Enzyme Activity
Sulfa inhibits the enzyme that uses PABA for synthesis of folic acid

18. Factors Influencing Enzyme Activity
Noncompetitive inhibition
Figure 5.7a, c

19. Feedback inhibition
Figure 5.8

20. The Generation of ATP
ATP is generated by the phosphorylation of ADP.

21. The Generation of ATP
Substrate-level phosphorylation is the transfer of a high-energy PO4- to ADP.

22. The Generation of ATP
Energy released from the transfer of electrons (oxidation) of one compound to another (reduction) is used to generate ATP by chemiosmosis.

23. Metabolic Pathways
Step 1 is a redox. Who is reduced and who is oxidized. The double arrows indicate that both occur in this step. The forward and backward indicate that the reaction goes the same forward and back. Why is step 1 not like this?

24. Carbohydrate Catabolism
The breakdown of carbohydrates to release energy
Glycolysis
Krebs cycle
Electron transport chain

25. Glycolysis
The oxidation of glucose to pyruvic acid, produces ATP and NADH.

26. Preparatory Stage 2 ATPs are used
Glucose 1
2 ATPs are used
Glucose is split to form 2 Glyceraldehyde-3-phosphate
Glucose
6-phosphate 2
Fructose
6-phosphate 3
Fructose
1,6-diphosphate 4 5
Glyceraldehyde
3-phosphate
(GP)
Dihydroxyacetone
phosphate (DHAP)
Figure

27. Energy-Conserving Stage6
1,3-diphosphoglyceric acid 7
2 Glucose-3-phosphate oxidized to 2 Pyruvic acid
4 ATP produced
2 NADH produced
3-phosphoglyceric acid 8
2-phosphoglyceric acid 9
Phosphoenolpyruvic acid
(PEP) 10
Pyruvic acid
Figure

28. Glycolysis
Glucose + 2 ATP + 2 ADP + 2 PO4– + 2 NAD+  2 pyruvic acid + 4 ATP + 2 NADH + 2H+

29. Alternatives to Glycolysis
Pentose phosphate pathway:
Uses pentoses and NADPH
Operates with glycolysis
Use and production of 5 carbon sugars (na)
Bacillus subtilis, E. coli, Enterococcus faecalis
Entner-Doudoroff pathway:
Produces NADPH and ATP
Does not involve glycolysis
Pseudomonas, Rhizobium, Agrobacterium
Generally not found in your gram positives. Can work without glycolysis

30. Cellular Respiration
Oxidation of molecules liberates electrons for an electron transport chain
ATP generated by oxidative phosphorylation

31. Intermediate Step
Pyruvic acid (from glycolysis) is oxidized and decarboyxlated
Figure

32. Krebs Cycle
Oxidation of acetyl CoA produces NADH and FADH2

33. Krebs Cycle
Figure

34. The Electron Transport Chain
A series of carrier molecules that are, in turn, oxidized and reduced as electrons are passed down the chain.
Energy released can be used to produce ATP by chemiosmosis.

35. Chemiosmosis
Figure 5.15

36. Electron transport and Chemiosmosis
Figure

37. Figure 5.14

38. 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 cycles operations under anaerobic conditions.

39. Anaerobic respiration
Electron acceptor
Products
NO3–
NO2–, N2 + H2O
SO4–
H2S + H2O
CO32 –
CH4 + H2O

40. Energy produced from complete oxidation of 1 glucose using aerobic respiration
Pathway
ATP produced
NADH produced
FADH2 produced
Glycolysis 2
Intermediate step
Krebs cycle 6
Total 4 10

41. By substrate-level phosphorylation By oxidative phosphorylation
ATP produced from complete oxidation of 1 glucose using aerobic respiration
36 ATPs are produced in eukaryotes.
Pathway
By substrate-level phosphorylation
By oxidative phosphorylation
From NADH
From FADH
Glycolysis 2 6
Intermediate step
Krebs cycle 18 4
Total 30

42. Pathway
Eukaryote
Prokaryote
Glycolysis
Cytoplasm
Intermediate step
Krebs cycle
Mitochondrial matrix
ETC
Mitochondrial inner membrane
Plasma membrane

43. Fermentation Releases energy from oxidation of organic molecules
Does not require oxygen
Does not use the Krebs cycle or ETC
Uses an organic molecule as the final electron acceptor

44. Fermentation
Figure 5.18b

45. Fermentation Alcohol fermentation. Produces ethyl alcohol + CO2
Lactic acid fermentation. Produces lactic acid.
Homolactic fermentation. Produces lactic acid only.
Heterolactic fermentation. Produces lactic acid and other compounds.

46. Fermentation
Figure 5.19

47. Fermentation
Production of acid and gas
Figure 5.23

48. Lipid Catabolism
Figure 5.20

49. Protein Catabolism Protein Amino acids Organic acid Krebs cycle
Extracellular proteases
Protein
Amino acids
Deamination, decarboxylation, dehydrogenation
Organic acid
Krebs cycle

50. Biochemical tests
Used to identify bacteria.
Figure 10.8

51. Halobacterium uses bacteriorhodopsin, not chlorophyll, to generate electrons for a chemiosmotic proton pump.

52. Chemotrophs Use energy from chemicals. Energy is used in anabolism.
Chemoheterotroph
Energy is used in anabolism.
Glucose
NAD+
ETC
Pyruvic acid
NADH
ADP + P
ATP

53. Chemotrophs Use energy from chemicals.
Chemoautotroph, Thiobacillus ferroxidans
Energy used in the Calvin-Benson cycle to fix CO2.
2Fe2+
NAD+
ETC
2Fe3+
NADH
ADP + P
ATP
2 H+

54. Metabolic Diversity Among Organisms
Nutritional type
Energy source
Carbon source
Example
Photoautotroph
Light
CO2
Oxygenic: Cyanobacteria plants.
Anoxygenic: Green, purple bacteria.
Photoheterotroph
Organic compounds
Green, purple nonsulfur bacteria.
Chemoautotroph
Chemical CO
Iron-oxidizing bacteria.
Chemoheterotroph
Fermentative bacteria.
Animals, protozoa, fungi, bacteria.

55. Metabolic Pathways of Energy Use
Polysaccharide Biosynthesis
Figure 5.28

56. Metabolic Pathways of Energy Use
Lipid Biosynthesis
Figure 5.29

57. Metabolic Pathways of Energy Use
Amino Acid and Protein Biosynthesis
Figure 5.30a

58. Metabolic Pathways of Energy Use
Amino Acid and Protein Biosynthesis
Figure 5.30b

59. Metabolic Pathways of Energy Use
Purine and Pyrimidine Biosynthesis
Figure 5.31

60. Amphibolic pathways
Are metabolic pathways that have both catabolic and anabolic functions.
Figure

61. Amphibolic pathways
Figure