Micro 3050 exam 2

(Bacterial)Endospores

A complex, dormant, survival structure that is formed by some bacteria (usually gram positive bacteria that live underground) (location within the cell is species specific). Useful because these structures are RESISTANT to: heat, radiation, chemicals, and desiccation(drying out) and therefore can like for 1000s of years in their dormant form.

Exosporium

Part of endospore structure, the most outer layer that is composed of proteins.

Spore Coat

Part of endospore structure, the multiple layers of protein that are impermeable to toxins.

Cortex

Another layer of protection around an endospore, composed of peptidoglycan that is less cross-linked than in normal cell walls.

Core

The innermost part of an endospore, this contains the cytoplasm and all the essentials of a cell (similar to the interior of a bacterial cell with a FEW differences.

Germ Cell Wall

A part of the endospore that is also made of peptidoglycan, becomes the cell wall when the bacterim emerges (when germination occurs the protective outer layers are lost).

Gliding

A type of bacterial motility, *smooth* movements that may involve a pili and/or *slime*.

Twitching

A type of bacterial motility that occurs when pili are at the ends of the cell and cells are in contact with each other and with a surface. Appears as short, intermittent, jerky motions.

Spirochete

A type of bacterial motility that exhibits flexing and spinning movements. Caused by multiple flagella forming an *axial fibril* which then winds around the cell itself. The flagella all remain in the periplasmic space found right inside the outer sheath.

Chemotaxis, chemo

Movement towards a chemical attractant OR away from a chemical repellent. The ______attractants and ____repellants are dectected by ____ receptors on the surfaces of cells. A complex BUT rapid process (response in less than 20 milliseconds).

Run, tumble(lower frequency of tumbles)

If a bacteria senses a POSITIVE chemotaxis, it will ______ more and ______ less.

Tumble, run

If a bacteria's chemoreceptors sense a chemorepellant then the bacteria will _______ more and ______ less.

Flagellum

Threadlike appendages found extending outward from the plasma membrane and cell wall of bacteria. Functions:
-Motility and *Swarming* behavior (all going one place)
-Attachment/burrowing to surfaces
-*Virulence factor*(in some cases)

Peritrichous

A pattern of flagella distribution, spread over *entire* surface of cell (peri= perimeter).

Lopotrichous

A pattern of flagella distribution, a cluster of flagella at one or BOTH ends of the bacteria.

Amphitrichous

A pattern of flagella distribution; ONE flagellum (not a cluster) at each end of the cell.

Polar Flagellum

Pattern of flagella distribution; flagellum are found only at ONE END of the cell.

Monotrichous

A pattern of flagella distribution; describes a cell with only one flagellum on it.

Run

When flagellum rotates *counterclockwise* it will cause this type of forward motion.

Tumble

In general, when flagellum rotate *clockwise* this will cause this type of movment, the run is disrupted so the cell stops and does this.

3 parts of a flagella

1. Filament- hollow tube made of proteins
2. Hook- a single piece of protein.
3. Basal Body (*Motor*)- made of 4 rings and allows the flagellum to spin.

PMF(proton motive force)

The source of energy for flagellum rotation, uses the protein gradient across the cell membrane as a source of potential energy (charge moves back and forth across the plasma membrane as protons go back and fourth across the PM).

L and P

These 2 layers of the basal body (motor) of a flagella *DO NOT SPIN*(the outermost rings).

MS and C

These 2 layers of the basal body (motor) of a flagalla *WILL SPIN*(innermost rings) when enough proton motive force is generated.

1000

The number of protons that need to cross the plasma membrane in order to generate enough energy for ONE 360 degree spin of the flagellum.

Stator

One of the two parts of a flagellum "motor", made of Mot A and Mot B which create a channel for protons to flow through, generating PMF and causing the flagellum to rotate.

Rotor

One of the 2 parts of a flagellar motor, made of the MS ring and C ring which turn and interact with the stator (other part of the motor).

Torque

The flagellum's 2 part motor (rotor and stator) produces this type of motion.

2(one on the cytoplasm side and one of the peptidoglycan side).

The number of rings in flagellum of *gram-positive bacterium*.

4

The number of rings in the flagellum of a *gram-negative bacterium* (since it does not have very thick peptidoglycan to hold it in place).

Sporation

Anything in a cell's environement that causes growth to stop (usually nutrient depletion) will cause the cell to go into this. The process of beginning to make a spore.

Germination

When a spore becomes a vegetative cell, this process is triggered when _____ receptors on the inner membrane of the endospore detect that there is proper water/nutrients (it is not sage to become active and become a cell instead of staying in endospore form). The point of no return because water gets allowed into the spore so that it will swell and rupture the protein spore coat and break out on its own. This will cause a *loss of resistance*(because now a normal cell) and an *increase* in metabolic activity.

Endospore Resistance

Caused by having a low water content in the core (things cannot move around or react), Calcium dipicolinate (Ca-DPA) to further dehydrate the core and stabilize DNA making it more resistant to harsh chemicals, SASPs (small acid-soluble proteins) that further compact and protect DNA by binding, and a slightly lower pH in the core. ALSO the exosporium and spore coat are layers that are impermeable to toxins and chemicals and therefore give extra protection.

Metabolically Active(until after germination when it does become active)

An endospore is NOT ________ ______.

Fimbriae(aka Pili)

A short, thin, hairlike appendage made up of protein (up to 1,000 per cell). These function to help the cell attach to surface and some types (Type IV) may be required for *motility* or DNA uptake.

Sex Pili

A bacterial structure that is similar to fimbriae but longer , thicker, and less numerous. The genes to form this structure are found on *plasmids*. These structures are REQUIRED for *conjugation*(horizontal gene transfer, sending DNA across via this structure)

Requirements for Microbial Survival(and growth)

-Source of Energy(for cellular work)
-Source of electrons (reduce carbon dioxide to form *organic* molecules and produce energy)
-Nutrients (*Carbon, hydrogen, and oxygen* to synthesize organic building blocks)

Sunlight

A source of ENERGY (only) for microbes

Oxidizing

Energy is obtained by doing this to either organic or inorganic compounds, this means removing the electrons from a compound.

ATP(Adenosine triphosphate)

The most common energy storage molecule is cells, how energy is conserved for later use (other ways to do this but this is the most common).

Metabolism

The total of ALL *chemical* reactions occurring in a cell.

Catabolism

Part of metabolism; considered to be "Fueling reactions" that are also energy-conserving. Provide the *reducing power*(aka electrons) to generate the precursors for biosynthesis. These reaction break things down to get the building blocks you need for other reactions.

Anabolism

Part of metabolism; the synthesis (building) of complex ORGANIC molecules from simpler building blocks. Requires energy, electrons, and building blocks from FUELING reactions.

Chemotrophs

Nutritional type of organism classified based on ENERGY source; obtains energy through the oxidation (removal of electrons) of chemical compounds.

Phototrophs

Nutritional classification of organism based on ENERGY source; uses light to obtain energy.

Lithotrophs

Nutritional classification of microbe based on ELECTRON source; use reduced *inorganic* substances for electrons.

Organotroph

Nutritional classification of organism based on ELECTRON source; obtains electrons from *organic* compounds.

Heterotroph

Nutritional classification of microbe based on CARBON source; uses *organic molecules* as a carbon source (same source often serves as the energy and electron source as well).

Autotroph

Nutritional classification of microbe based on CARBON source; uses carbon dioxide as their sole/principle carbon source ("primary producers") so they must obtain electrons and energy from OTHER SOURCES.

Chemoorganoheterotroph

The nutritional classification of humans (organic carbon for carbon, organic chemicals for energy, and organic electron donor for electrons).

Organic molecules(so H2 is INORGANIC)

Molecules that contain carbon and hydrogen

Catabolism, anabolism.

You MUST have ________ (reduction/break down) to have ________ (synthesis).

Free Energy(delta G)

The amount of energy that is available to do useful work in a cell (work such as chemical synthesis, transport, and/or mechanical work such as motility).

Standard Free Energy(Delta G prime)

The change in free energy during a chemical reaction AT STANDARD CONDITIONS (pH 7, temperature of 25 celcius, 1 atm, and 1 M concentration of reactants and products).--conditions may change depending on changes in the cell.

Energy

The capacity to do work or to cause particular changes.

Exergonic

This type of reaction releases energy so deltaG' is *negative* because the reaction proceeds SPONTANEOUSLY (rock rolling down a hill).

Endergonic

This type of reaction REQUIRES energy so deltaG' is *positive* and the reaction will NOT proceed spontaneously (need to put energy in to make something go--like anabolism).

ATP

Cells have evolved to use this molecule as their primary energy source (not necessarily the best energy rich source but most commonly used). 32 kj/mol of energy are released when the first phosphate group is hydrolyzed and broken off (less energy released for each subsequent phosphate that is broken off).

Endergonic, ATP

We couple _______ reactions with ____ in order to move them forward and make them go.

30 kj/mol

The minimum change in standard free energy that cells require in order to use other energy-rich compounds besides ATP.

Standard Reduction Potential(E'o)

The measure of a compound's TENDENCY to donate electrons(reducing agent to lose electrons).

Negative

A more ______ standard reduction potential is a better(when comparing 2 molecules) electron DONOR.

Positive

A more _________ standard reduction potential will be a better (comparing 2 molecules) electron ACCEPTOR.

Oxidation(OIL)

The REMOVAL of an electron(or electronS) from a substance.

Reduction(RIG)

The ADDITION of an electron(or electrons) to a substance(often the one that has gained a hydrogen).

(Electron)Acceptor

Electrons released during the *oxidation* of chemical energy source must be accepted by this.

Donors, acceptors

On the Redox tower, molecules near the top (more negative) are better electron ________ and molecules near the bottom are more positive as therefore better electron ______.

Negative

The greater the standard reduction potential (E'o) between the donor and acceptor, the more ________ the deltaG'o (further you drop the babies--electrons-- the louder they scream)

Left, donates, reduced, right

On the redox tower, the oxidized form is on the ____ side and is always the one that ______ electrons. Once they accept electrons they become the ______ form which is on the ______ side of the tower.

Photosynthesis

During this process, light energy is used to drive electrons UP the redox tower.

Coenzyme

A class of electron carriers that are freely diffusible meaning that they can transfer electrons from one place to another in the cell (such as NAD+), good electron donors AND acceptors (nanny in a mini van picking up electron kids).

Prosthetic Groups

Class of electron carriers that are firmly attached (fixed) to enzymes in the plasma membrane and function in membrane-associated electron transport reactions, do not move around the cell (nanny at home).

Catabolism

NAD+ is involved in this metabolic process, it is a redox electron carrier that is a coenzyme (nanny in mini van). Carrier 2e- and 1 H+.

Anabolism

NADP+ is involved in this metabolic process, a redox electron carrier that is a coenzyme. Carrier 2e- plus 1 H+.

Good electron donors

NADH and NADPH are both considered to be this

NAD+(this is the oxidized form of NADH.. NAD+--> NADH--> NAD+)

A crucial coenzyme that is needed to accept electrons for critical parts of metabolism (if we do not have the oxidized problem our cell is in trouble) and we naturally do not have very much of it in our cells SO we must reuse/recycle it.

Substrate-level Phosphorylation

A mechanism of ATP synthesis that is used for FERMENTATION, the synthesis of ATP occurs as another organic compound is broken down (catabolized--ADP to ATP).

Oxidative Phosphorylation, SLP

A mechanism of ATP synthesis used in RESPIRATION (with or without oxygen), the synthesis of ATP occurs via *proton motive force* and makes more ATP than ______ _____ __________.

Photophosphorylation

A mechanism of ATP synthesis used by phototrophic organisms, ATP synthesis occurs when *light* drives redox reactions that generate proton motive force.

Fermentation, absence, pyruvate, SLP, fermentation

A fueling process that takes place in the _____ of an exogenous electron acceptor (oxygen is not needed), ________ or a derivative is recycled and used as the ELECTRON ACCEPTOR instead. ATP is produced via _________ and _______ products are also created. (NO ETC or PMF).

Glycolysis, NAD+, NADH, fermentation

Fermentation begins with ______, when going from GLyceraldehyde-3-P to 1,3-biphosphoglycerate in there is no ________ to take electorns and become ________ +H then __________ cannot happen (the first step of fermentation).

Waste(products)

Fermentation products can be considered to be this because the whole reason for making them is so that NAD+ can go back and be used in glycolysis.

Mixed Acid

These type of fermenters are often gram negative and can be detected using a methyl red test. They make MANY different acids (E. coli is this type of fermenter).

2,3-Butanediol

A fermentation class of acid producers, to test if a bacteria falls in this class you would use a VOGES-PROSKAUR test to detect intermediate *Acetonin*.

Eukaryotic

In this domain the electron transport chains are located in the inner mitochondrial membrane.

Bacteria and Archaea

In these domains the electron transport chains are located mostly in the cytoplasmic membrane.

3:1

P/0 ratio for ATP to NADH

2:1

P/0 ratio of ATP for every FADH2

BETA

ATPase motor (smallest biological motor), this subunit will go back to its original active site conformation when ATP (that was inside) is released.

Aerobic Respiration

Catabolizes an organic energy source to CO2 by using:
1. Glycolytic Pathway
2. CAC (Kreb's) Cycle
3. Electron transport chain(with Oxygen as the final electron acceptor)

--RECYCLES electron carriers and produces ATP

38(8 from glycolysis and 15x2 from CAC)

The number of ATP per glucose produced from Aerobic respiration.

38, 4, 34

The maximum net yield of aerobic respiration is ____ ATP with ___ coming from SLP and _______ coming from oxidative phosphorylation.

Anaerobic

In this type of respiration the electrons will not fall down to the bottom of the tower (oxygen is not the final electron acceptor) so it will yield less overall energy.

Growth

In microbiology, this refers to an increase in the NUMBER of cells.

One Generation

In Binary fission, going from one cell to two cells is considered to be this

Binary Fission(most common form of growth)

1. Cell elongation- cellular constituents increase proportionally
2. Genome is replicated and segregated
3. Cell division-septum formed at midcell
4. Increase in cell number

Generation Number(number of generations)

n=3.3(logNt-logN0)

--Nt is population at time t
--N0 initial population number

Generation Time(the time it takes to make each generation)

g=t/n

Batch

A microbial growth cycle (growth curve) is observed when microorganisms are cultvated in this type of culture, incubated in a closed vessel with a SINGLE batch of medium.

Starvation Responses

-Morphological Changes: endospore formation, decrease in size
-Production of Starvation Proteins-- chaperone proteins can renature DNA
-Persister cells- more sticky, long-term survival