Microbiology 1: Microbial Metabolism (Ch 5)
Much of this chapter should be review!
I. Metabolism
A. what is it?
B. parts
anabolism
catabolism
C. need raw materials & energy
D. ATP
II. Enzymes
A. enzyme structure
1. usually protein
2. exception: ribozyme
3. holoenzyme
a. apoenzyme
b. cofactor
B. function
1. catalysts
2. how many?
3. substrate
4. product(s)
C. mechanism(s)
1. active site
2. sequence of events:
E + S(s)
--> ES (transition state)
--> E + P(s)
D. Factors influencing reactions
optimum
1. temperature
2. pH
denaturation
3. substrate concentration
4. inhibitors
a. competitive
b. allosteric/non-competitive
5. feedback inhibition
E. “-ase”
III. Biological energy production
A. oxidation/reduction reactions (redox)
1. oxidation
2. reduction
3. coupled
hydrogenation/dehydrogenation
B. ATP production
1. substrate level phosphorylation
2. oxidative phosphorylation
3. photophosphorylation
ATPase
© copyright 2013 Marta D. de Jesus
IV. Glucose Catabolism
A. glycolysis = Embden-Meyerhoff pathway
1. glucose
2. 8 steps
3. Energy-investment stage
Energy-conserving stage
4. net effect: 1 Glucose (6C) ------------>
2 NAD+ + 4 H ----------->
also make 4 ATP - use 2 ATP ---->
5. O2
6. bacterial alternatives
a. pentose-phosphate pathway
b. Entner-Doudoroff pathway
B. Fate of pyruvate
1. respiration
a. pyruvate
b. ATP
c. final e- acceptor
d. types
1) aerobic respiration
(i) transition/preparatory reaction
2 pyruvate (3C) -->
2NAD+ + 4H -->
(ii) Krebs/Citric acid/TCA cycle
2 Acetyl CoA (2C) -->
Also make ATP (#?)
make NADH2 (#?)
make FADH2 (#?)
(iii) electron transport (ETC)
NADH and FADH2
O2 ->
H+’s
(iv) chemiosmosis
H+’s
(v)) summary
2) anaerobic respiration
(i) no O2
(ii) ATP
2. fermentation
a. O2
b. Krebs cycle, ETC, ATPase
c. final e- acceptor
d. ATP
e. NAD+ (and NADP+)
f. some types
1) homolactic = homofermentative
2) alcoholic
3) propionic acid
4) acetone & isopropanol
5) heterolactic = heterofermentative
V. Other Catabolic Pathways (won’t stress)
VI. Biosynthesis = Anabolism
A. Photosynthesis
1. several kinds
a. Halobacterium (Archaea)
1) bacteriorhodopsin
2) H+
b. green sulfur & purple sulfur bacteria
1) bacteriochlorophylls
2) CO2
3) O2
c. cyanobacteria & photosynthetic eukaryotes
1) chlorophyll a
2) CO2
3) O2
2. oxygenic PS in more detail
a. chloroplast anatomy & the 2 kinds of reactions
b. light dependent reactions
1) photosystems
PSI
PSII
2) cyclic photophosphorylation
3) non-cyclic photophosphorylation
c. light independent/dark reactions = Calvin-Benson cycle = carbon fixation
1) CO2
2) RUBISCO
B. chemosynthesis
1. bacteria (eg: nitrifying, sulfur, iron, hydrogen, carbon)
2. archaea (eg: methanogens, hyperthrmophiles)
C. Other biosynthesis pathways (won’t stress)
1. gluconeogenesis
2. formation of fatty acids & glycerol
3. formation of amino acids
4. formation of nucleotides
D. amphibolic pathways
Online Metabolic Maps
IUBMB-Nicholson Metabolic Maps, Minimaps & Animaps
http://www.iubmb-nicholson.org/
KEGG PATHWAY Database: Wiring diagrams of molecular interactions, reactions, and relations
http://www.genome.jp/kegg/pathway.html