Module 5 Microbial Metabolism (PPT) Flashcards
bacterial products examples (commercially or medically important)
i.e. Lactococcus and Lactobacillus, Streptococcus mutans
microorganisms that are important in laboratory (identification of microorganisms) (3)
(i.e. E. coli, Klebsiella, and Enterobacter)
- oxidative ; exergonic (releases energy); breaking down
- reductive ; endergonic; building up
- Catabolism
- Anabolism
Energy Source: Sunlight
Carbon Source: Carbon dioxide
Photoautotroph
Energy Source: Sunlight
Carbon Source: Organic compounds
Photoheterotroph
Energy Source: Inorganic chemicals
Carbon Source: Carbon dioxide
Nitrogen Source: Inorganic
Chemolithoautotroph
Energy Source: Organic compounds
Carbon Source: Organic compounds
Nitrogen Source: Organic or Inorganic
Chemoorganoheterotroph
Energy Source: Sunlight
Carbon Source: Carbon dioxide
Nitrogen Source: Inorganic
Hydrogen Source: H2S or H2
Bacteria
Energy Source: Sunlight
Carbon Source: Carbon dioxide
Nitrogen Source: Inorganic
Hydrogen Source: Photolysis of H20
Cyanobacteria
Energy Source: Sunlight
Carbon Source: Carbon dioxide
Nitrogen Source: Inorganic
Hydrogen Source: Organic compounds
Photoorganotrophic Bacteria
- “sugar splitting”
- occurs in cytosol of bacteria
- converts glucose (6-C) to pyruvate (3-C)
- can occur in the absence of oxygen
- enzyme-mediated
Glycolysis
Glycolysis order (11)
- Glucose
- Glucose 6-phosphate
- Fructose 6-phosphate
- Fructose 1,6-bisphosphate
- (optional) Dihydroxyacetone phosphate
- Glyceraldehyde 3-phosphate
- 1,3-Bisphosphate glycerate
- 3-Phosphoglycerate
- 2-Phosphoglycerate
- Phosphoenolpyruvate
- pyruvate
10 enzymes in glycosis
- Hexokinase
- Phosphoglucoisomerase
- Phosphofructokinase
- Aldolase
- Triose Phosphate isomerase
- Glyceraldehyde phosphate dehydrogenase
- Phosphoglycerokinase
- Phosphoglyceromutase
- Enolase
- Pyruvate kinase
Glycolysis gross energy yield and net energy yield
- gross energy yield = 4 ATP + 2 NADH
- net energy yield = 2 ATP + 2 NADH
- phosphogluconate pathway or hexose monophosphate shunt
- other metabolic pathway used by cells to break down glucose
Pentose Phosphate Pathway
- generates NADPH, ribose 5-phosphate, and erythrose 4-phosphate
(intermediates)
Pentose Phosphate Pathway
Pentose Phosphate Pathway (6)
- Glucose
- Glucose 6-P
- 6-Phosphogluconate
- Ribulose 5-P
- Ribose 5-P -> nucleotide synthesis (opt)
- Erythrose 4-P / Xylulose 5-P / Sedoheptulose 7-P
- Fructose 6-P / Glyceraldehyde 3-P
aerobic (O2-requiring) breakdown of nutrients with accompanying synthesis
of ATP
Aerobic Respiration
Aerobic Respiration comprises three stages in the metabolic breakdown of glucose
❑ transition step/conversion of pyruvate to acetyl CoA
❑ Krebs cycle / citric acid cycle
❑ oxidative phosphorylation: electron transport chain and chemiosmosis
Aerobic Respiration takes place in the
cytoplasm
- pyruvate converted to acetyl coenzyme A
Transition Step
Transition Step
- removal of carboxyl group from pyruvate and given off as ________
- 2-C compound is oxidized, ______ is reduced to _______
- _________ joins the 2-C compound forming acetyl-coenzyme A (acetyl CoA)
- CO2
- NAD+ -> NADH
*coenzyme A
Transition Step energy yield (per glucose):
2 NADH
- named after Hans Krebs
- also known as citric acid cycle or tricarboxylic acid cycle
- yields more energy than glycolysis
Krebs Cycle
Krebs Cycle (8)
- Acetyl-CoA (release CoA) + Oxaloacetae
- Citrate
- Isocitrate: (NADH, H+, CO2)
- α-ketoglurate: (ATP, NADH, H+ , CO2)
- succinyl CoA
- succinate: (FADH2)
- fumarate
- Malate: (NADH, H+)
Krebs Cycle energy yield (per glucose)
2 ATP + 6 NADH + 2 FADH2
- final stage of cellular respiration
- “big energy payoff” stage
- uses electron transport chain and chemiosmosis
- located in the cell membrane
Oxidative Phosphorylation
membrane-embedded electron carriers that pass electrons sequentially from one to another
electron transport chain
movement of ions (H+) down their electrochemical gradient that generates ATP
chemiosmosis
Electron carriers (4)
- I – flavoprotein (flavin monunucleotide)
- II – Fe-S protein
- Quinone (Q)- non-protein mobile carrier ; aka CoQ
- Cytochrome (C) – mobile carrier; Q to oxygen
– enzyme that makes ATP from ADP and inorganic phosphate
- uses energy of ion gradient top power ATP synthesis
ATP synthase
Prokaryotes have varied types and arrangement of electron transport chain components which could provide a mechanism to distinguish certain types of
bacteria for example
cytochrome production of Pseudomonas and Campylobacter
Detects the presence of an enzyme “oxidase” produced by certain bacteria which will reduce the dye – tetramethyl-p-phenylene diamine dihydrochloride.
is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain
Positive test is indicated by the development of a purple colour.
OXIDASE TEST
Oxidase positive (3) PURPLE COLOR
Pseudomonas, Vibrio, Neisseria