Microbiology Exam 2

minimal growth temperature

the temperature that starts to allow bacteria to grow (slow)

optimal growth temperature

the perfect temperature that allows growth at a steady rate

maximum growth temperature

the highest temperature that allows growth at a fast rate

Psychophiles

(20-40) bacteria that can live in freezing cold temperatures - the reason we have mold

mesopholies

bacteria that can live in cold temperatures but not freezing temperatures 

thermophiles 

bacteria that can live in warm termpatures

hyperthermophiles

bacteria that can live in hot temperatures

What is the name of the microbes responsible for the spoilage of food?

psychotrophs 

acidophiles

prefer acidic living conditions (1-6)

neutriophiles

prefer to live in nuetral conditions (7)

alkailphiles

prfer to live in basic conditions (8-12)

What pH condition do microbes prefer?

Most of them prefer to live in neutral conditions

what are the three terms to decribe microbs osmostic pressure likes and wants

halophiles, osomphiiles, and pieziophiles  

Halophiles

like to live in high salt concentration (hyper)

Osmophiles

like to live in high solute concentrations (sugars, etc.)

Pieziephiles

like to live in dry conditions

What are the key organic elements?

Carbon, Nitrogen, Phosphorus, and Sulfur

Why is the importance of the key organic elements?

Each element is used in the essential organelles for life, so without these elements, there would be no life. 

Obligate Anerobes

requires O2 to produce energy

Facultative Anaerobes 

don’t require O2 but will prefer to use it 

Obligate Anarobes

DONT need O2, refuse to use it

areotolerent aerobes

doesn’t use O2, but can survive in its presence

microareophiles

only needs low dose of O2

what is the difference between chemotrophs and phototrophs?

chemotrophs use chemical reactions to produce energy, while phototrophs use light reactions

What is the diffrence between chemoautotrophs, chemoheterotrophs, photoautotrophs, and photoheterotrophs?

chemeoautotrphs use CO2 to produce energy compared to heterotrophs that use other organic molecules. same goes for phototrpohs

BInary Fission

prokaryotic’s reproductive process that results in two identical daughter cells.

What are the two main proteins involved in binary fission?

FtsZ and MreB

What is a general step-by-step process of binary fission?

1) Origin of replication is copied

2) They move to opposite ends of the cell

3) the cell wall grows inward, creating a septum with the help of FtsZ and MreB

What are the stages of the bacterial curve growth?

lag, log, stationary, decline (death)

How can you quantify bacteria directly?

1) direct counting 2) most probable number 3) filtration 

How can you quantify bacteria indirectly?

1) Turbidity 2) metabolic activity 3) dry weight

What is the method of direct counting to measure the amount of bacteria?

serial dilute bacteria and grow them on agar plates, and then count the number of colonies grown.

What is the method of Turbidity to measure the amount of bateria? 

Bacteria grow in a tube, and the liquid will become cloudy, and then the optical density will be measured the amount of bacteria in the tube.

What are the oxidized and reduced forms of NAD, ATP, NADPH, and FADH2? 

Oxidized: ATP, NAD+, NADPH, FADH2

Reduced: ADP, NADH, NADP, and FAD

What is the ratio of NAD/NADH? What is the primary role of this molecule?

about 1000 of NAD, and it serves a crucial role in catabolic reactions.

What is the ratio of NADP/NADPH? What is the primary role of this molecule?

about 0.01 of NADPH, and serves a crucial role in anabolic reactions. 

What are the 3 main catabolic pathways to energy production for the cell?

1) anerobic 2) anaerobic 3) fermentation

What is an example of a catabolic reaction?

cellular respiration

what is an example of an anabolic reaction?

photosynthesis

What is the number of ATP produced during aerobic, anaerobic, and fermentation?

aerobic - 36-36, anaerobic - less than 36, more than 2, fermentation - 2

what are the 3 main sets of rection during cullular respiration?

1) glycolysis 2) Krebs cycle 3) ETC 

What is the EMP pathway?

metabolic breakdown of glucose.

What are the starting products, byproducts, and ending products of the EMP pathway?

start - 6-C glucose, byproducts - (2) NADH and (2) ATP, end - (2) 3-C pyruvate acids.

Where does the EMP pathway occur in both prokaryotes and eukaryotes?

both occur in the cytoplasm

What is the ED pathway?

An alternative metabolic pathway to the EMP that breaks down glucose.

What are the starting products, byproducts, and end products of the ED pathway?

start - 6-C glucose, byproducts - (1) NADH + (1) NADPH + (1) ATP, end - (2) 3-C pyruvic acid.

What types of organisms do the ED pathway instead?  

1) aerobes 2) faculative aerobes 3) phototrophic species

Why don’t obligate anaerobes use the ED pathway?

It can’t sustain the low ATP yield compared to the EMP pathway, and some enzymes are sensitive to oxygen.

What is the OPP pathway?

a catabolic pathway that breaks down glucose into ribose phosphate and NADPH.

Why is the OPP considered a catabolic pathway but also an anabolic precursor?

The OPP pathway breaks down glucose to produce ribose phosphate and NADPH, which are used heavily in anabolic pathways. 

What are the two phases during the OPP pathway? What is the product of each?

Oxidative phase: oxidation of glucose into ribose phosphate, NADPH, and CO2.

Non-Oxidative phase: production of ribose phosphate to link to glycolysis or amino acids.

What is the primary role of ribose phosphate?

used to produced DNA, RNA and ATP

What is the primary role of NADPH?

helps with anabolic reactions

What are some beenfits of having multiple carbohydrate catabolic rections in a cell?

1) flexibility 2) ability to swtich in case of mutation knocking out one of the pathways

IF a cell had all three carbohydarte catabilic pathways, what order would they occur?

1) EMP 2) ED 3) OPP

Where does the conversaion of pyruvic acid into acetyl CoA occur in both prokaryotes and eukarotes? 

prokaryotes - cytoplasm, eukaryotes - mito matrix

What are the two byproudcts during the conversion of pyruvic acid to acytely CoA?

(2) NADH and (2) CO2

What are the TWO functions of PDC during pyruvic acid conversion?

1) converts puruvic acid into acetyl CoA 2) converts some of the acetyl CoA into acetyl phosphate, which is a carbon starvation sensor. 

What is the Kreb Cycle?

conversion of acetyle CoA to oxaloacetate

What is the purpose of krebs cycle?

During the cycle, there are a lot of byproducts that are crucial substrates of building blocks for biosynthesis pathways. 

What are the starting materials, byproducts, and end products of the Krebs cycle?

start - acetyle CoA, byproducts - (2) CO2 + (3) NADH + H+ + ATP + FADH2, end - oxoloacetate

What is the Glyoxylate Bypass?

skips the CO2 losses that occur during the Krebs cycle.

What is the starting amtieral, byproducts, and end of the Glyoxylate Bypass?

start - acetyle CoA, byproducts - NADH and FADH2, end - oxoloacetate. 

Why would a prokaryote rather use the bypass rather than the kreb cycle? 

When a prokaryote needs to synthesizDee glucose from fatty acids or acetate. 

Describe the events which occur during the oxidative phosphorylation phase (ETC). 

1) electrons from NADH and FADH2 are passed through the ETC

2) the engery from the electrons passing through the chain create an H+ proton gradient

3) electrons are picked up by a final receptor (O2)

4) protons in the outside matricx are syntehsized into the inner matrix to generate ATP

Where does the ETC take place for both prokaryotes and eukaryotes?

prokaryotes happen on the plasma membrane and eukarotes happend on the inner mito membrane. 

What is the Mitchell Extrusion Hypothesis?

how the ETC works.

What is anarobic respiration?

The final electron receptor is any molecule besides oxygen.

What types of microbes employ anaerobic respiration?

oligate anaerobes and faculative anaerobes. 

Order from most to least reduction potential (sulfate, iron, anerobe, maganese, methanogens, and denitrifies).

1) anerobes 2) denitrifies 3) manganese 4) iron 5) sulfate 6) methanogens

What are the four types of anarobic respiration?

1) denitrification 2) sulfate reduction 3) methanogenesis 4) metal-reducers

For denitrification, what is the order of most oxidized to least oxidizing potential?

N2, N2O, NO, NO2, NO3

What does sulfate reduction need to reduce the oxidized sulfate?

ATP

What is the difference between dissimilatory and assimilatory sulfate reduction?

D: breaks down sulfate molecules for H2S release into the atmosphere.

A: builds sulfate to aid in the construction of amino acids. 

What are the two main oxidized starting molecules for methangenesis?

CO2 and CH3COO-

What are the four metal-reducers?

1) Cobalt 2) Uranium 3) Maganese 4) Iron

What is fermentation?

ineffienct breakdown of sugar molecules without oxygen.

What are the two main types of lactic acid?

1) homolactic 2) herterolactic

What is the difference between homo and hetero lactic acid fermentation?

Homo: direct conversion, NO CO2 produced 

Hetero: indirect conversion, CO2 produced

What two enzymes are involved in ethanol fermentation, and what are the products of each? 

1) pyruvic decarboxylase - acteldehyde 2) alcohol dehydrogenase - ethanol 

What are the four alternative fermenation pathways? 

1) Mixed acid 2) Butanol 3) Butanediol 4) Propionic

What is the net equation for the oxygenic photoautotrophy?

CO2 + H2O —> 6CH12O6 + O2

What happens during photosystem II?

1) light is captured 2) energy is bounced between protons 3) ETC and H2O as the final receptor to restore the e- 4) The ETC is used to punmp the H+ grandient to generate ATP

What happens during photosystem I?

1) captures light 2) uses the electrons from the ETC from PS2 3) generates NADPH

What are the TWO main light-harvesting pigments?

chlorophyll and bacteriochlorphylll

what are the main acessory pigments, and what do they do?

carotenoid, phycocyanin, and phycoerythrin. They max the light absorption. 

What are the 3 proteins used in the ETC during photosynthesis?

Pc, Fe, and Pq

What are the names of the proteins that generate ATP and NADPH?

ATP syntheses and NADP+ reductase

What are the 3 main events during the Calvin Cycle?

1) Carbon Fixation 2) Reduction 3) Regeneration

What is the input and putput of Calvin Cycle?

ATP and NADPH into calvin cycle —→ G3P comes out

What are the TWO alternatives to Calvin Cycle? 

1) reverse TCA 2) reductive acetyl-CoA

What are the FOUR types of phosynthesis that prokaryotes use?

1) oxygenic photoautotrophy

2) anoxygenic photoautotrophy

3) anoxygenic photoheterotrophy

4) Rhodopsin-based 

What are the chracteristics of the four photosynthesis?

1) OPA: 2 photosystems, produce O2, use CO2, cyanobacteria

2) APA: 1 photosystem, no O2 produced, uses other molecules as electron donors to fix CO2, purple and green sulfur bacteria

3) APH:  NO CO2, NO O2, 1 photosystem, and purple non-sulfur bacteria 

4) RP: archea