Metabolism

Macronutrients

Required in relatively large amounts

Micronutrients

Required in relatively small amounts

Trace elements

inorganic micronutrients

Growth factors

organic micronutrients

protiens essential in cell division

filamentious temperature sensitive protein.

Bacitracin

binds to and inhibits 

dephosphorylation of bactoprenol, 

blocking its recycle

Vancomycin

blocks transpeptidation 

but by binding to D-Ala-D-Ala and preventing cross-linking

β-lactam antibiotics (eg. Penicillin)

block 

transpeptidation by directly binding and 

preventing the activity of transpeptidase.

Cycloserine

inhibits two enzymes 

that make D-Ala-D-Ala dipeptide

β-lactam antibiotics & Vancomycin

block transpeptidation so when the autolysins 

make holes in the membrane and the cell tries to fill it in with new 

peptidoglycan it can’t cross-link the glycan chains and the cell lyses.

Doubling Time

amount f time required for a cell number to doube

also knwn as genration time

Batch culture 

 a closed-system microbial culture of fixed volume (no extra 

nutrients except the ones to start with and no waste removal)

Growth Yield

amount of biomass produced during bacterial

growth on a given substrate

Y

ATP

Grams of dry cell material

produced per mole of ATP

Cardinal temperatures

Minimum,

Optimum, and Maximum temperatures

characteristic of each microorganism

Psychrophiles

cold loving. Cellular macromolecules function at low temps

minimum T at or below 0°C

Optimum T at or below 15°C

Maximum T below 20 ° C

Psychrotolerant

Organisms that grow at 0°C (not well but do grow) but have

optima of 20 - 40°C.

At -30°C cellular growth stops but some enzymatic

reactions can continue.

At -140°C all enzymatic reactions stop.

Storage of bacteria in laboratory

Bacterial strains can be stored at -80 or -135 in 7%

Dimethylsulfoxide

glycerol

(DMSO) or 10 - 25%

Mesophiles

Organisms that live at the temperature range of warm blooded mammals.

Minimum T : 10°C

Optimum T : about 37°C(98.6°F)

Maximum T : about 45°C

Thermophiles

Above ~65°C only prokaryotic life forms exist

Hyperthermophiles

(extreme):

Acidophiles

Organisms that prefer low pH.

- Many fungi prefer this. Also many bacteria are

acidophiles.

- In these organisms, the plasma membrane is

concentration and when

Alkaliphiles

- Prefer high pH.

- Usually found in regions with high carbonate

deposits (soda lakes).

Internal pH has been found to be as low as 4.6 and high as 9.5 in extreme

acido- and alkaliphiles, respectively, which are thought to be the limits

Neutrophiles

Halotolerant

Grow optimally at

normal salt concentrations

(0.85%) but are able to grow well

at high salt concentrations

(reduced water activity) (7.5%)

Halophiles

Organisms which

grow optimally in salt

concentrations equal to sea

water. (3% NaCl + many other

minerals)

Extreme halophiles

Organisms that live in extremely salty environments (15-

30% NaCl). Some actually grow on salt crystals

Osmophiles

Organisms that live in high sugar concentrations.

Xerophiles

Organisms that live in very dry environments

Water Activity(a

vapor pressure of water in the substance

Obligate anaerobes

Microaerophilic

Need oxygen  but at concentrations below those found in the

Helicobacter pylori

Aerotolerant

Growth same in presence and absence of O

(lactic acid

Obligate anerobes

are Killed by O

2 (Clostridium

inducible

Genes that are not on all of the time

inducers

molecules that turn on transcription

constitutive

Genes that are always turned on (transcribed)

Operon

unit of transcription

(gene expression).

Gyrase

is the enzyme that introduces

negative supercoiling.

Topoisomerase I

is an enzyme that cleaves the

phosphodiester bond in a single strand in the DNA and

causes the tension to relax

Reverse gyrase

an enzyme that catalyzes

positive supercoiling in some extreme thermophiles