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Chapter 6 Micro
chapter 6 Microbiology
80
Microbiology
Undergraduate 3
04/02/2011

Additional Microbiology Flashcards

 


 

Cards

Term
Generation time
Definition

time required for a population of microbial cells to double , during cell division each daughter cell receives a chromosome and sufficient


Term

Ftsz

Definition
forms ring around center of cell; related to tubulin- which is important to cell divsion protin in eukaryotes
Term

Zip A

Definition

 

ZipA: anchor that connects FtsZ ring to cytoplasmic membrane

 

Term
Zip A
Definition
ZipA: anchor that connects FtsZ ring to cytoplasmic membrane
Term
Ftsa
Definition

helps connect FTSZ ring to membrane and also recruits other divisome proteins

 

related to actin most abundant protein in eukaryoyotes

Term
function of Min proteins
Definition
assist in determining the location of FtsZ rung
Term
DNA replicates before Ftsz ring can form
Definition
Term
function minc mind
Definition
mind of mice work together to inhibit cell division by precenting the FtsZ ring from forming
Term
function of MinE protein
Definition
sweeping minc and D aside
Term
function of FTsk
Definition
protein mediates separation of chromosomes to daughter cells
Term

MreB*** function

 


Definition

Major shape-determing factor in prokaryryotes

 

Term

 

function of MREb

 

 

2 functions

Definition

   - Forms simple cytoskeleton in cells of bacter and archeae

  

Forms spiral shaped bonds around the inside of the cell underneath the CM

 

Term

iN WHAT KIND OF bacteria can of MREb be found?

 

 

Definition

- Not found in COCCUS shaped bacteria only rod


-        Localized synthesis of new peptidoglycan and other cell walls compounds to specific location along the cylinder of rod-shaped cell during growth

 

coccus + peptido


Term
autolysin what is it
Definition

 

Autolysins are a group of enzymes that exist in all bacteria containing peptidoglycan. these enzymes break down the peptidoglycan matrix in small sections so that growth and division of cells can occur. Autolysins do this by hydrolyzing the β-(1,4) bond between N-acetylmuramic acid and N-acetylglucosamine molecules.

Term

Peptidoglyccan synthesis

 

requirements

Definition

 Preexisting peptidoglycan needs to be severed to allow newly synthesized peptidoglycan to form

autolysins

New cell wall material is added across the openings

Wall band: j

Term
MOST ARCHAEAL GEMONES CONTAIN WHICH PROTEINS?
Definition
FTZ AND MREB
Term
PROCESS OF PEPTIDOGLYCAN SYNTHESIS AND CELL DIVISION
Definition

links in the peptidoglycan must be broken, new peptidoglycan monomers must be inserted, and the peptide cross links must be resealed.

 

  1. autolysinsp-
  2. Bactoprenol- l
  3. Glycolases- e
  4. Transpeptidation
Term
step 1 of synthesis, what occurs and by what?
Definition

autolysin

  1. autolysinsp- break glycosidic bonds/ Break the peptide cross-bridges- FtsZ ring, small openings in the wall are created

wall band created- new and old peptidoglycan

Term
step 2
Definition
bactoprenol- inserts petodiglycan precurso c5 alcohol, which bonds to G/M petapeptide petido precursors
Term

step 3

 

Definition

 

  1. Glycolases- enzymes interacting with bactoprenol- catalyze glycosidic bond formation to insert cell wall precursors into growing point of cell wall
Term
STEP 4
Definition
  1. Transpeptidation-  final step in synthesis- FORMS PEPTIDE CROSS LINKS B/W M residues adjacent glycan chain

PEPTIDE BONDS B/W G---M(peptidoglycin bond)

3. glycosidic bond b.w (M--M bond)

 

penicillin inhibits m--m bond causing inhibition  transpeptidase enzymes that catalyze this reaction. The activity of this enzyme is inhibited by penicillins

Term

how does penicillin inhibit function of transpeptidation

 

mechanism and consequence

Definition
have transpeptidase enzymes that catalyze the production of cell wall synthesis by inhibiting glycosidic bond b/w M-M. The activity of this enzyme is inhibited by penicillins causing lysing of bacteria
Term
summary of cell wall synthesis
Definition

Bactoprenol is placed into MEMBRANE, autolysin begins GM interacts with peptidoglycan with assistance of glycolases enzyme, and autolysin assist in separating membrane

Term
what are two criterias the generation time of bacteria are dependent on
Definition

1. growth medium- the amount of resources needed to grow

2. incubation conditions- temp/ heat/ ph/ enviroment

 

Term
formula for expoententia growth of bacteria within x amount of hours
Definition

2^n

 

too nice

Term
formula for calculating generation time
Definition
t/n
Term

Specific growth rate (k)

 

division (v)

 

 

 

 

 

Definition

k = log2/g =

 

v= 1/g

 

g= t/n

 

N= N. * 2^n

 

N= final cell number

N.- intital cell number

n- number of generations during period of expoenential growth

Term
read up on calculations make sure you have right formulas
Definition
Term
bach culture
Definition

a closed system microbial culture of fixed volument

 

Term
4 phases of typical growth curve for population of cells grown in closed systems
Definition

lag phase- time b/w culture is inoculated and when growth begins

expoential phase- phase are typically in healthiest state

stationary phase- growth rate of population is zero, someetimes some die while others are growing static

death phase

Term

stationary phase how we come to crystic growth

 

 

Definition
some die some grow- 1. either an essential nutrient is used up or 2. waste product of org accumulates in the medium
Term
define death phse
Definition

rate of cell death is MUCH lower than the rate of expoential growth

 

this doesnt mean everything is dead

Term
know what cryptic growth is
Definition
Term
chemostat- growth rate is controleld by what?
Definition
dilution- high water outside
Term
growth yield is controlled by
Definition
concentration of limiting nutrients
Term
in contrast to chemostat batach culture growth conditions are constantly changing is it possibly to control batch culture growth rate and yield
Definition
No- constantly changing
Term
Increasing limiting nutrient concentration results in greater mass, doe sit change growth rates
Definition
No, it just supples culture with necessary resourcces to continue current growth,  can not "speed" up their own personal rate of growth
Term
when is organism "washed out"
Definition
high dilution rate, too much water
Term
cells die from saturation when
Definition
too low a dilution rate ( no enough water)
Term
what is the difference between chemostat and batch culture
Definition

we can c ontrol the growth of CHEMOSTAT

 

stat- keep track of

Term

 

what are the limitations of microscopic counts

Definition
  1. live vs dead(w/o staining)
  2. small cells difficult to see and can be overlooked
  3. precision difficult to achieve
  4. phase-contrast microscope required if stain is not used
  5. cell suspension- low density hard to count
  6. motile cells need to be immobilized
  7. debris- mistaken for cells

we already know

Term
flow cytometry
Definition
measurements of total cell numbers
Term
define cytometry
Definition
measurement of cells or cellular particles as they move in a fluid stream past stationary set of dectators
Term
Calculate the cell numbers
Definition
Term
viable cell counts (plate counts) function?
Definition
measurement of living, reproducing population
Term
2 ways to perform plate counts
Definition

spread plate method

pour- plate method

Term
to obtain appropriate colon number what should be done
Definition

always dilute sample.

 

DILUTION

Term

FIGURE 6.16**

Definition
Term
The Great Plate Anomaly
Definition

Direct microscopic counts of natural samples typically reveal more organism then are recoverable on plates of any given culture medium.

Term

 

why is it in great plate anomaly does Direct microscopic counts of natural samples typically reveal for more organism then are recoverable on plates of any given culture medium.

Definition

Microscopic methods count dead cells; whereas viable (plate counting) methods do not

Different organisms in even a very small sample may have vastly different requirements for resources and conditions in laboratory culture

 

Term
function of turbidity measurements
Definition

indirect but:  very rapid and useful method of measuring microbial growth.

(Most often measured with a spectrophotometer and measurement referred to as optical density (O.D.)

Term

To relate a direct cell count to a turbidity value what must be done** and why?

Definition

A standard curve must first be established

 

Typically do not require destruction or significant disturbance of sample

Sometimes problematic

       Microbes that forms clumps or biofilm in liquid medium

Term
Cardinal temperatures
Definition

 

 

min/ optimum/ and maximum temperatures at which an organism grows

Term
psychotrphile
Definition
low temps- 4 C
Term
mesophile
Definition
mid range 39 C
Term
thermophile 60
Definition
Term
hyperthermophile
Definition
very high temp 88 c
Term
exremophiles
Definition
org. envolved to grow optimally under hot cold conditions
Term
psychtrophiles
Definition
org with cold temp tima (most extreme representatives inhabit permanently cold enviroments)
Term
psychrophiles
Definition
org with cold temp optima (most extreme represetntatives inhabit permanently cold enviroments)
Term
psychrotolerant
Definition
org grow at 0 but optima between 20-40 C, widely distrubuted in nature than pschrophiels
Term

prokaryotes can grow at higher temp then eukaryotes

archaea can live in hottest

Definition
Term
abce 65 only what kind of life exists?
Definition
prokaryotic life forms
Term
enzymes tht function optimally in cold have what kind of characteristics
Definition
  1. more alpha helic- flexible
  2. more polar less hydrophobic AA
  3. fewer weak bonds
  4. dec interaction b/w protein domains
Term
what assists org to stay liquid in extremem colds
Definition
CM has high unsaturated fatty acid content, (unsaturated means more flexible) double bonds
Term
describe membrane of arachea
Definition
single layer membrane- lipid rich in saturated fatty acids which forms a strong hydrophobic enviroment then do unsaturated fatty acids
Term
what kind of motive force does alkaliphiles posses
Definition
Na motive force rather than PMF
Term
internal pH of cell must remail relatively neutral eventhough outside is extreme of either ends
Definition
Term
Water activity (aw)
Definition

ratio of vapor pressure of air in equilibrium with a substance or solution to the vapor pressure of pure water (nothing in water except H2O) no living org in i, water activity decreases with increases of solute such as Na

 

think osmosis

Term
compatible solutes
Definition

glycinbetainse

prolinse

sucrose

trehalose

Term
halophiles
Definition
grow best at reduced water potential- have a specific requirements for NaCl
Term
extreme halophiles
Definition
org that require HIGH levels of nacl for growth
Term
osmophiles
Definition
org that live in enviroment with sugar as solute
Term
xerophiles
Definition

very dry enviroments

 

 

Term
mechanisms for combating low water activity (high solute concentration) in surrounding enviroment increasing internal solute concent.
Definition

-        High solute concentration outside= water moves out to prevent this

o   Pumping inorganic ions from environments into cells.

o   Synthesize and accumulation of organic solutes called compatible solutes( glycin betains, preline, sucrose, trehalose):compound used by cells to counteract low water activity in surrounding environments.

Term
toxic forms of oxygen
Definition

single oxygen

superoxide

h2o2

hydroxyl radical

Term
how to neutralize toxic oxygen species
Definition

catalase

 

enzyme that destryo toxic oxygen spcies

Term
 Cirtic acid cycle generates…
o Alpha- ketooglutarate and oxaloacetate (OAA)
 Precursors of several amino acids
 OAA also converted to PEP; OAA PEP
o Succinyl coA
 Required for synthesis of cytochromes and chlorophyll
o Acetyl coa- nec for fatty acid biosynthesis
Definition
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