Microbial Metabolism

Question 1

–Enzymes found within the cytosol of the cell

–Active inside the cell

Answer 1

•Endoenzymes

Question 2

–Enzymes secreted by cell into environment

–Active outside the cells

Answer 2

•Exoenzymes

Question 3

•Some enzymes need accessory molecules such as:

Answer 3

1. Co-factor
2. Co-enzyme

Question 4

•inorganic helper, metal ions common, Mg++, Mn++

Answer 4

Co-factor (accessory molecule for enzyme)

Question 5

•organic non-protein helper, NAD, FAD

Answer 5

Co-enzyme (accessory molecule for enzyme)

Question 6

Answer 6

Oxygenic Photosynthesis

Question 7

Answer 7

Holoenzyme

Question 8

Type of Enzyme Activity Regulaton

–Competitive inhibition

–Allosteric (non-competitive) inhibition

–Allosteric activation

Answer 8

•Enzyme level regulation

Question 9

Type of Enzyme Activity Regulation

–Transcription control (genetics lecture)

Answer 9

•Genetic level regulation

Question 10

Answer 10

Competitive inhibition

Question 11

Answer 11

Allosteric Inhibition

Question 12

Answer 12

Allosteric Activation

Question 13

Type of Metabolism Regulation

–If two energy sources are available, cells use the more energy efficient of the two first

–If glucose and lactose both available, lac operon off until glucose levels low

Answer 13

•Catabolite repression

Question 14

Type of Metabolism Regulation

–Cells may synthesize molecules only as needed, cease synthesis if molecules readily available

–In trp biosynthesis, trp is co-repressor for trp operon, trp also is allosteric inhibitor for enzyme in biosynthesis

Answer 14

•Feedback inhibition

Question 15

Answer 15

Feedback Inhibition

Question 16

Sum of all chemical reactions occurring within a cell

Answer 16

Metabolism

Question 17

–Series of chemical reactions mediated by enzymes

–Product of one reaction becomes substrate of the next

–Catabolic metabolism

–Anabolic metabolism

Answer 17

•Metabolic pathway

Question 18

Answer 18

Metabolic Pathway

Question 19

–Break larger molecules into smaller products (hydrolysis)

–Exergonic (release energy)

–ATP generated

Answer 19

•Catabolic pathways

Question 20

–Synthesize large molecules from the smaller products of catabolism (dehydration synthesis)

–Endergonic (require energy)

–ATP consumed

Answer 20

•Anabolic pathways

Question 21

Question 22

•Energy stored in high energy bond in ATP

Answer 22

–Phosphorylation

Question 23

•ADP made into ATP in three ways

Answer 23

–Substrate-level phosphorylation

–Oxidative phosphorylation

–Photophosphorylation

Question 24

Answer 24

Substrate-level phosphorylation

Question 25

•Four major strategies for producing ATP are Note: * All pathways are redox reactions * Can be differentiated by products, final electron acceptors

Answer 25

–Aerobic respiration –Anaerobic respiration –Fermentation –Photosynthesis

Question 26

–Presence of electron transport system –Chemiosmosis –Aerobic respiration –Anaerobic respiration

Answer 26

Cellular Respiration

Question 27

–Uses oxygen as a final electron acceptor –Glucose + ADP + O2 ATP + CO2 + H2O –Four steps in overall pathway 1. •Glycolysis 2. •Acetyl CoA synthesis 3. •Krebs cycle 4. •Electron Transport Chain (chemiosmosis) –Produces 34-36 ATP

Answer 27

Aerobic Respiration

Question 28

•NAD+ –Required coenzyme for 1. •Glycolysis 2. •Acetyl-CoA synthesis 3. •Krebs cycle –Reduced to NADH during these processes –Oxidized back to NAD+ at electron transport chain

Answer 28

Aerobic Respiration

Question 29

* –Uses an electron transport system and chemiosmosis * –Uses an inorganic oxygen containing molecule as the final electron acceptor * –NO3-, SO4-2, CO2 * –Less efficient than aerobic respiration, produces less than 34 ATP per glucose * •Does NOT occur in eukaryotes

Answer 29

•Anaerobic Respiration

Question 30

–Reduction of CO2 to CH4 –*Methanococcus spp.*

Answer 30

•Carbon dioxide respiration (Anaerobic Respiration)

Question 31

–Reduction of SO4 to HS ## Footnote *–Desulfobacter spp.*

Answer 31

•Sulfate respiration (Anaerobic Respiration)

Question 32

–Reduction of NO3 to N2 ## Footnote *–Paracoccus denitrificans*

Answer 32

•Nitrate respiration (Anaerobic Respiration)

Question 33

–Glucose via 2 pyruvate, 2 ATP, 2 NADH –Typical glycolysis

Answer 33

•Embden-Meyerof-Parnas Pathway (Glycolysis)

Question 34

–Glucose via 2 pyruvate, 1 ATP, 1 NADH, 1 NADPH

Answer 34

•Entner-Doudoroff pathway (Glycolysis)

Question 35

–Glucose via 2 NADPH, CO2, ribulose-5-phosphate

Answer 35

•Pentose-Phosphate pathway (Glycolysis)

Question 36

* Uses organic molecule as final electron acceptor * Oxidizes NADH to NAD+ so that metabolism can continue * Low yields of ATP per glucose (1-2 ATP) * End products vary by organism – due to differences in metabolic enzymes

Answer 36

Fermentation

Question 37

–Glucose + 2 ADP yields 2ATP + CO2 + Ethanol ## Footnote *–Saccharomyces cerevisiae*

Answer 37

•Alcohol fermentation (EMP Fermentation)

Question 38

–Glucose + 2 ADP 2ATP + lactate –Many bacteria and us

Answer 38

•Acid fermentation (EMP Fermentation)

Question 39

* Lactic acid fermentation * Propionic acid fermentation

Answer 39

Other Fermentations

Question 40

–Lactic acid only end product –Glucose + 2ADP yields 2 lactate + 2 ATP *–Lactobacillus spp., Lactococcus spp.*

Answer 40

(Lactic Acid Fermentation) •Homolactic fermentation

Question 41

Answer 41

Homolactic Fermentation

Question 42

–Lactic acid, ethanol and CO2 –Glucose + ADP yeilds ethanol + lactate + CO2 + ATP *–Leuconostoc spp.*

Answer 42

•Heterolactic fermentation (Lactic Acid Fermentation)

Question 43

Answer 43

Heterolactic Fermentation

Question 44

•End products include propionic acid, acetic acid, carbon dioxide –Critical part of making Emmentaler (swiss cheese) *–Propionibacterium freudenreichii*

Answer 44

Propionic Acid Fermentation

Question 45

Answer 45

Propionic Acid Fermentation

Question 46

Type of photosynthesis ## Footnote –Use of light energy to produce ATP and reduced NADPH –ATP and NADPH used in light independent reactions

Answer 46

•Light dependent reactions

Question 47

Type of photosynthesis ## Footnote –Autotrophs use this captured energy (ATP and NADPH) to fix inorganic carbon

Answer 47

•Light independent reactions

Question 48

Answer 48

•Anoxygenic photosynthesis | (Light Dependent Reactions)

Question 49

Answer 49

•Oxygenic photosynthesis (Light Dependent Reactions)