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What do most organisms use for energy?
CHO catabolism
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What happens to pyruvate after glycolysis?
- Aerobic Respiration - 02 present
- Fermentation (anaerobic, O2 inhibits)
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What cofactor is required for glycolysis?
NAD+
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What is Glycolysis?
- Catabolizes glucose to 2 pyruvates
- Universal pathway in cytoplasm
- No O2 requirement, nets 2 ATPs/glucose
- Requires NAD+ electron carrier as cofactor
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What is nicotinamide?
NADH or NAD
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What is the fate of pyruvate if conditions are anaerobic?
- No O2
- Aerobic respiration does not occur so glycolysis is only source of ATP and MUST CONTINUE
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What is critical for gylcolysis to occur?
Oxidize NADH to NAD+, results from fermentation
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What is fermentation?
- Always occurs anaerobically
- Reduces pyruvate, oxidizes NADH to NAD+
- Fermentation end products produced as a result
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What are the two types of fermentation?
- Lactic Acid Fermentation
- Alcoholic Fermentation
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What is Lactic Acid Fermentation?
- Pyruvate reduced directly to lactic acid
- Acid denatures (curdles) milk protein, flavors 'clutured' dairy products
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What is alcoholic fermentation?
- Mainly by yeast
- Pryuvate decarboxylation + reduction to CO2 and ethanol (alcohol, leaven bread, fuel)
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What are some food produced during bacterial fermentation?
Vinegar, sauerkraut, pickling, soy sauce, other products
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What happens on the molecular level during lactic acid fermentation?
Pryuvic Acid to Lactic Acid (Reduced NADH to Oxidized NAD+)
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What happens on the molecular level during alcohol fermentation?
- Pyruvic Acid to Carbon Dioxide + acetaldehyde (via decarboxalation)
- Acetaldeyhde to ethyl alcohol (NADH to NAD+)
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What bacteria MUST use O2?
- Obligate/strict aerobes
- Aerobic Respiration only
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What type of bacteria MUST NOT use O2?
- Strict Anaerobes
- Fermentation Only
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What type of bacteria will use O2 if present but can also ferment without O2?
Facultative Anaerobes
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What is the energy yield during Aerobic Respiration?
- Faster Growth
- Yields 36-38 ATPs/glucose
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What is the energy yield during Anaerobic Respiration?
- Growth is Slow
- Yields 2 ATP/glucose
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What is happening on the molecular level during aerobic respiration?
Acetyl-CoA is produced by decarboxylation and oxidation of pyruvate
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What occurs during the Kreb Cycle? Location?
- Acetyl-CoA 2 carbon units oxidized
- In prokaryote cytoplasm
- Generates critical reducing potential (NADH, FADH2) also CO2 and some ATP
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What is the Electron Transport Chain? Where is it located?
- Located in the Cell Membrane
- NADH, FADH2, passes electrons via carriers to O2
- H+ pumping creates proton gradient
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What is Oxidative Phosphorylation?
Proton gradient drives ATP synthesis by ATP synthase
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What are the oxygen conditions during Glycolysis?
Anaerobic, O is not required; does not stop however if O is present
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What is the starting and ending material for the Kreb Cycle?
- 2 pyruvic Acid/6 CO2, 8 NADH, and 2 FADH
- 2 ATP produced
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What are the staring and molecules for the Electron Transport Chain?
- 6 O2/6 H2O
- 34 ATP produced
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What are the starting and ending molecules for glycolysis?
- 1 glucose/2 pyruvic acid and 2 NADH
- 4 ATP, (2 Net)
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What is the breakdown of ATP production during Aerobic conditions?
- Glycolysis 10
- Pyrvuate 6
- Kreb Cycle 24
- Less E for Phosphorylation -2
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What is the breakdown of ATP production during Aerobic conditions?
- Glycolysis 4
- Less E for Phosphorylation -2
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How do lipids and proteins enter metabolic pathways to produce energy?
- Fats - beta oxidation - Kreb - ETC - ATP
- Proteins - AA - AA Catabolism - Kreb - ETC
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How does Prokayotic cell division occur?
Binary Fission
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What occurs during binary fission?
- DNA replication
- Mother cell divides to form 2 daughter cells
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What is the process of cell division in prokayotic cells?
- No cycle Cycle
- Nucleotide divides; cell wall and membrane begin to form transverse septum
- Transverse septum becomes complete
- Daughter Cells seperate
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What occurs during each phase of the Bacterial Growth Curve?
- Lag Phase (few mins) - Cell division, increased metabolism
- Log Phase - Exponential Growth, Highest metabolism, shortest generation time, MOST SENSITIVE to DAMAGE
- Stationary Phase - Nutrients decline, wastes increase, pH changes
- Death or Decline Phase - Nutrients depleted, wastes toxic, exponential death. Sporulation of possible
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What are the PHYSICAL bacterial growth factors?
Temperature, pH, and Osmotic Pressure
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What are the effects of temp on bacterial growth factors?
- Affect on enzyme activity
- Each species has minimum, optimal, and max. temp.
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What is a psychrophile?
Cold-loving (water, soil, fridge)
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What is a mesophile?
25-40 C, includes most pathogens, spoilage bacteria
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What is a Thermophile?
- Heat-loving, 50-60 C
- Hot Springs
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What is an Extreme Thermophiles?
- Deep Sea Vens
- Eg - Archaeabacteria (some thrive at 115 C)
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What is an acidophile?
grow below pH 5.5
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What is a Neutrophiles?
- pH 5.5-5.8
- Includes most pathogens (pH 6.5-7.5)
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What are Alkaliphiles?
Prefer pH 8-12
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What occurs in a HYPOTONIC environment?
Cells Swell
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What occurs in a HYPERTONIC environment?
- Cause cell shrinkage (plasmolysis), inhibit growth
- Jam
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What are Halophiles?
Require HIGH salt
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What are extreme halophiles?
Thrive at 20-30% Salt
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What are the are the chemical factors that alter microbial growth?
- Carbon
- Oxygen: Potential poison, but required by many organisms
- Nitrogen
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What are superoxide anions (O2-)?
Formed when growth in O2 environments results in oxidative rxns, toxic
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What are superoxide anions (o2-) detoxified?
- Superoxide dismutase
- (SOD) + Catalase (CAT) enzymes
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What are the requirements of Obligate aerobes?
O2 required, no fermentation enzymes (SOD+, CAT+)
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What are the requirements of Obligate Anaerobes?
O2 is toxic (SOD-, CAT-)
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What are the requirements of facultative anaerobes?
Use of O2, but can ferment (SOD+, CAT+)
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What are the requirements for Microaerophiles?
Grow only at low [o2] (SOD+, CAT-)
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What is the role of Nitrogen in Microbial Growth?
- AA, Nucleotides
- Nitrogen-fixing Bacteria
- N2 gas into NH3, which is then accessible to other organisms
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What are Fatidious microbes?
- Difficult to grow due to complex nutritional needs
- Usually due to absence of enzymes required for synthesis of nutrients
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What is sterilization?
Removes/kills ALL microbes, absolute (autoclave)
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Commercial sterilization?
Destroys C. botulinum endospores
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Disinfection?
Reduces number of potentially pathogenic microbes
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What is an anticeptic?
Disinfects living tissue
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When are disinfectants used?
Non-living objects
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What are the mechanisms of chemical agent action?
- Protein denaturation
- Membrane solubilization/destruction
- Alkylating agents
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What are Alkylating agents?
CH3 (alkyl) groups, disrupts cell structures, cause mutations
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What factors influence anti-microbial effectiveness?
- Number if microbes, exposure time
- Microbial Characterisitcs (endospores)
- Environmental Influences (temp, deactivates when organic material is used)
- Bacericidal vs Bacteristatic agent used
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What are antimicrobial agents?
- Surfactants: (soaps and detergents) aide removal and not bactericidal
- Alcohol: (70% in H2O) denatures proteins, dissolves membranes
- Heavy Metals: Bind/deature proteins
- Halogens: oxidize, denature proteins
- Alkylating Agents: Denature proteins, disrupt nucleic acids. Formaldehyde, ethylene oxide (sterilizes)
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What are some physical antimicrobials?
- Heat: Moist is better that dry heat (autoclave)
- Pasteurization: Kills pathogens in liquid, specific temp for a specific amount of time, NOT sterilization
- Radiation: (ionizing high energy), Common for heat sensitive products
- Filtration: (of liquids or air), Membrane pore size excludes microbes
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