1. Microbial Metabolism

2. What is metabolism? All chemical reactions/activities in cell
Catabolism
Hydrolysis
Use energy to make ATP
ADP + Pi + energy  ATP
Anabolism
Dehydration synthesis
Need energy for reaction
ATP  ADP + Pi + energy
Enzymes frequently catalyze reactions
Oxidation/reduction

3. What is the difference between…
Hydrolysis
Condensation (dehydration synthesis)
Exergonic vs. endergonic

4. What are enzymes? Without enzymes, collision theory rules
Need sufficient activation energy
Number of molecules above this activation level = reaction rate
Enzymes are molecules that lower the ______________
Catalysts
Work on substrate…

5. What does the enzyme work on?
Substrate
Molecules which are changed during reaction
Enzyme-substrate complex forms temporarily
Lock and key model
Highly specific fit
End in -ase
Turnover number
Number of molecules enzyme converts per second
DNA polymerase = 15; lactate dehydrogenase = 1,000

6. What are the parts of an enzyme?
Some are only a polypeptide chain
Most have two parts
Apoenzyme (polypeptide chain)
Cofactor (inorganic) or coenzyme (organic)
NAD+ (nicotinamide adenine dinucleotide) us. catabolic
NADP+ (nicotinamide adenine dinucleotide phosphate) us. anabolic
Coenzyme A (CoA)—pantothenic derivitive (another B vitamin)
Others are metals: Cu, Mg, Mn, Zn, Ca, Co
Together these form holoenzyme
From niacin

7. How does an enzyme work? Enzymes controlled by Enzyme synthesis
How much is made
Hormones can influence (e.g. TH)
Enzyme activity
Temperature influences
Denaturation
pH influences
Substrate concentration influences
Saturation point

8. How does an enzyme work? Inhibitors influence Competitive
Fill active site: sulfanilamide vs para-aminobenzoic acid (PABA)
Non-competitive
Allosteric inhibition

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

10. Factors Influencing Enzyme Activity
Temperature pH
Substrate concentration
Figure 5.5a

11. Factors Influencing Enzyme Activity
Competitive inhibition
Figure 5.7a–b

12. Factors influencing enzyme activity
Feedback inhibition
Figure 5.8

13. Cell Energetics

14. Oxidation-Reduction Oxidation is the removal of electrons.
Reduction is the gain of electrons.
Redox reaction is an oxidation reaction paired with a reduction reaction.
Figure 5.9

15. Oxidation-Reduction
In biological systems, the electrons are often associated with hydrogen atoms. Biological oxidations are often dehydrogenations.
Figure 5.10

16. What happens in carbohydrate catabolism?
Glucose usually is substrate
Glycolysis
2 ATP
Followed by either
Aerobic respiration
___ ATP
Anaerobic fermentation
No more ATP

17. What is ATP?
Adenosine triphosphate
Made by phosphorylating ______
Equation:

18. What is glycolysis? First step to making TP from glucose
Convert glucose to _____________
Some bacteria can breakdown other molecules
Pentose phosphate pathway (pentoses)
E. coli, Bacillus subtilis

19. What happens next?
If oxygen present 
No oxygen 

20. Preparatory Stage Two ATPs are used
Glucose is split to form two Glucose-3-phosphate 1 3 4 5
Figure 5.12, step 1

21. Energy-Conserving Stage
Two Glucose-3-phosphate oxidized to two Pyruvic acid
Four ATP produced
Two NADH produced 9
Figure 5.12, step 2

22. Intermediate Step
Pyruvic acid (from glycolysis) is oxidized and decarboyxlated.
Figure 5.13 (1 of 2)

23. What is the Krebs Cycle? AKA citric acid cycle
Acetyl CoA (2 carbons) releases energy
Produces ATP, CO2, NADH, FADH2
NADH and FADH2 to Electron transport chain (ETC)

24. What are some intermediates in the Krebs cycle?
Some drugs are metabolized similar to these:
citric acid (6 carbons)
iso-citric acid (6)
alpha-ketoglutaric acid (5)
succinyl CoA (4)
succinic acid (4)
fumaric acid (4)
malic acid (4)
oxaloacetic acid (4)
Krebs cycle animation

25. What is the electron transport chain?
Carrier molecules facilitate oxidation and reduction
Oxidation: loss of electron
Reduction: gain of electron
Transfer electrons from higher to lower energy compounds
Chemiosmosis w/ oxidative phosphorylation
Prokaryotes: PM
Eukaryotes: mitochondrial crista
Disruption of ETC leads to death!
Cyanide
First ETC animation
Second ETC animation

26. What is the sum reaction for aerobic respiration?
Glucose + 6 H2O + 38 ADP + 38 Pi 
6 CO2 + 6 H2O + 38 ATP

27. What happens in anaerobic respiration?
Final electron acceptor is not oxygen
Various amounts of ATP produced
Slower and less ATP than aerobic respiration
Uses some parts of Krebs cycle
Thus slower growth for anaerobes than aerobes

28. What is fermentation? Pyruvic acid from glycolysis
Converted to end-products
If bacteria only produce lactic acid = homolactic
No additional ATP

29. What is alcohol fermentation?
Also happens after glycolysis
Produces ethanol and CO2
Heterolactic: produces lactic acid + other acids, alcohols

30. What happens in lipid & protein catabolism?
Some bacteria don’t like carbs!
Lipases break down ______
Krebs cycle oxidizes products
Useful for oil spill clean up
Extracellular proteases & peptidases break down _______
Deamination converts amino acids to usable form for Krebs cycle
By production is ammonia

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

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

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

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