Microbial Metabolism

Question 1

Commercially or medically important bacterial products

Answer 1

Lactococcus and Lactobacillus, Streptococcus mutants

Question 2

Important in laboratory

Answer 2

Escherichia coli, Klebsiella, Enterobacter

Question 3

Importance of Microbial Metabolism

Answer 3

-Model for studying metabolic pathways and processes in eukaryotic cells
-Potential targets for antimicrobial drugs

Question 4

All chemical changes occurring in a
microorganism during its growth and
development for healthy and stable
maintenance

Answer 4

Microbial Metabolism

Question 5

Two classes of chemical reactions

Answer 5

-Anabolism
-Catabolism

Question 6

Release free energy and reducing power that are captured in the form of ATP and NADPH, respectively.

Answer 6

Oxidative, exergonic pathways of catabolism

Question 7

Consuming chemical energy in the form of ATP and using NADPH as a source of high energy electrons for reductive purposes.

Answer 7

Anabolic process, endergonic

Question 8

Transfer energy from ATP to complex molecules

Answer 8

Anabolic reactions

Question 9

Transfer energy from complex molecules to ATP

Answer 9

Catabolic reactions

Question 10

Metabolic pathways are a series of reactions catalyzed by:

Answer 10

Multiple enzymes

Question 11

Energy and Carbon Sources Used by
Different Groups of Prokaryotes

Answer 11

Photoautotroph, Photoheterotroph, Chemolithoautotroph, Chemoorganoheterotroph

Question 12

Energy source: Sunlight
Carbon Source: Carbon dioxide

Answer 12

Photoautotroph

Question 13

Energy Source: Sunlight
Carbon source: Organic compounds

Answer 13

Photoheterotroph

Question 14

Energy source: Inorganic chemicals
Carbon Source: Carbon dioxide

Answer 14

Chemolithoautotroph

Question 15

Energy source: Organic compounds
Carbon source: Organic compounds

Answer 15

Chemoorganoheterotroph

Question 16

❑ “sugar splitting”
❑ occurs in cytosol of bacteria
❑ converts glucose (6-C) to pyruvate (3-C)
❑ can occur in the absence of oxygen
❑ enzyme-mediated

Answer 16

Glycolysis

Question 17

• gross energy yield (Glycolysis) =

Answer 17

4 ATP + 2 NADH

Question 18

• net energy yield (Glycolysis) =

Answer 18

2 ATP + 2 NADH

Question 19

❑ phosphogluconate pathway or hexose monophosphate shunt
❑ other metabolic pathway used by cells to break down glucose
❑ generates NADPH, ribose 5-phosphate, and erythrose 4-phosphate
(intermediates)

Answer 19

Pentose Phosphate Pathway

Question 20

❑ aerobic (O2-requiring) breakdown of nutrients with accompanying synthesis
of ATP
❑ comprises three stages in the metabolic breakdown of glucose
❑ takes place in the cytoplasm

Answer 20

Aerobic Respiration

Question 21

three stages in the metabolic breakdown of glucose:

Answer 21

❑ transition step/conversion of pyruvate to acetyl CoA
❑ Krebs cycle / citric acid cycle
❑ oxidative phosphorylation: electron transport chain and chemiosmosis

Question 22

❑ pyruvate converted to acetyl coenzyme A
❑ undergoes chemical modification/ “grooming”

Answer 22

Transition Step

Question 23

Chemical Modification/”grooming”

Answer 23

❑ removal of carboxyl group from pyruvate and given off as CO2
❑ 2-C compound is oxidized, NAD+ is reduced to NADH
❑ coenzyme A joins the 2-C compound forming acetyl-coenzyme A (acetyl CoA)

Question 24

 Energy yield (per glucose in Transition Step):

Answer 24

2 NADH

Question 25

Each pyruvic acid molecule is broken down to form CO2 and a two-carbon acetyl group, which enters the Krebs cycle

Answer 25

Transition Reaction

Question 26

❑ named after Hans Krebs ❑ also known as citric acid cycle or tricarboxylic acid cycle ❑ yields more energy than glycolysis

Answer 26

Krebs Cycle

Question 27

❑ Energy yield (per glucose in Krebs cycle):

Answer 27

2 ATP +6 NADH + 2 FADH2

Question 28

❑ final stage of cellular respiration ❑ “big energy payoff” stage ❑ uses electron transport chain and chemiosmosis ❑ located in the cell membrane

Answer 28

Oxidative Phosphorylation

Question 29

membrane-embedded electron carriers that pass electrons sequentially from one to another

Answer 29

Electron transport chain

Question 30

movement of ions (H+) down their electrochemical gradient that generates ATP

Answer 30

Chemiosmosis

Question 31

Electron carriers (4)

Answer 31

❑ I – flavoprotein (flavin monunucleotide) ❑ II – Fe-S protein ❑ Quinone (Q)- non-protein mobile carrier ; aka CoQ ❑ Cytochrome (C) – mobile carrier; Q to oxygen

Question 32

– enzyme that makes ATP from ADP and inorganic phosphate - uses energy of ion gradient top power ATP synthesis

Answer 32

ATP synthase

Question 33

❑ varied types and arrangement of electron transport chain components ❑ could provide a mechanism to distinguish certain types of bacteria

Answer 33

Electron Transport Chain of Prokaryotes

Question 34

Detects the presence of an enzyme “oxidase” produced by certain bacteria which will reduce the dye – tetramethyl-p-phenylene diamine dihydrochloride.

Answer 34

Oxidase Test

Question 35

Positive test in Oxidase test is indicated by the development of a _________________

Answer 35

Purple Color

Question 36

Oxidase positive:

Answer 36

Pseudomonas, Vibrio, Neisseria

Question 37

Oxidase negative:

Answer 37

Salmonella, Shigella

Question 38

Energy conversion:

Answer 38

1 NADH = 3ATP 1 FADH2 = 2 ATP

Question 39

The balance sheet of aerobic respiration (Glycolysis substrate-level phosphorylation)

Answer 39

2 ATP

Question 40

The balance sheet of aerobic respiration (Glycolysis NADH conversion (2 NADH))

Answer 40

6 ATP

Question 41

The balance sheet of aerobic respiration (Transition step (2 NADH))

Answer 41

6 ATP

Question 42

The balance sheet of aerobic respiration (Krebs cycle substrate-level phosphorylation)

Answer 42

2 ATP

Question 43

The balance sheet of aerobic respiration (Krebs cycle: NADH )

Answer 43

18 ATP

Question 44

The balance sheet of aerobic respiration (Krebs cycle: FADH2)

Answer 44

4 ATP

Question 45

Total ATP in aerobic respiration

Answer 45

38 ATP

Question 46

❑ oxygen is not the final electron acceptor in the electron transport chain ❑ less efficient form of energy transformation than aerobic respiration ❑ less amount of energy is released in the reduction of inorganic chemicals other than molecular oxygen ❑ anaerobic or facultative bacteria

Answer 46

Anaerobic Respiration

Question 47

Sulfate reduction

Answer 47

Desulfovibro

Question 48

Carbon dioxide reduction

Answer 48

Methanobacterium and Methanococcus

Question 49

❑ makes a few ATP molecules ❑ Krebs cycle and oxidative phosphorylation are shut down ❑ organic molecule accepts the electrons (not O2) ❑ i.e. E. coli (use any of the three ATP-generating options), LAB (obligate fermenters), obligate anaerobes

Answer 49

Fermentation

Question 50

process by which light energy is converted to chemical energy

Answer 50

Photosynthesis

Question 51

Intermediary product of Photosynthesis in Microorganisms

Answer 51

ATP

Question 52

Major end-product of Photosynthesis in Microorganisms

Answer 52

Glucose

Question 53

❑ process takes place in cell membrane * contains chlorophyll or chlorophyll-like pigments * thylakoid membranes (cyanobacteria) * chlorosomes (green bacteria) * extensive cell membrane invaginations (purple bacteria)

Answer 53

Photosynthesis in Microorganisms

Question 54

Prokaryotes

Answer 54

Green Sulfur bacteria, purple sulfur bacteria, cyanobacteria

Question 55

Eukaryotes

Answer 55

Diatoms, dinoflagellates, algae

Question 56

Photosynthesis occurs in the same manner as eukaryotic microorganisms and green plants

Answer 56

Photosynthesis: Cyanobacteria

Question 57

Mg-containing green pigment that absorbs light energy

Answer 57

chlorophyll a

Question 58

Light-receiving systems

Answer 58

photosystems I and II

Question 59

* chlorophylls and accessory pigments * reaction center pigments * antennae pigments

Answer 59

Photosystems I and II

Question 60

Chlorophylls and accessory pigments

Answer 60

❑ bacteriochlorophylls ❑ carotenoids (photosymthetic prokaryotes and eukaryotes) and phycobilins (cyanobacteria and red algae)

Question 61

purple and green photosynthetic bacteria

Answer 61

bacteriochlorophylls

Question 62

electron donors in photosynthetic process

Answer 62

reaction center pigments

Question 63

“funnel”, make up antenna complex

Answer 63

antennae pigments

Question 64

❑ green sulfur bacteria and purple sulfur bacteria ❑ archaea (extreme halophiles)

Answer 64

Photosynthesis: Other Prokaryotes

Question 65

❑ do not use water as source of hydrogen ions ❑ fatty acids and other organic or inorganic substances are used as source of H+ ions ❑ no oxygen is liberated ❑ anoxygenic

Answer 65

green sulfur bacteria and purple sulfur bacteria

Question 66

bacteriorhodopsin pigment

Answer 66

archaea (extreme halophiles)