Biol 240 Topic 6

Front 1

List Macro/Micronutrients

Back 1

macro: C, N, P, S, O (all cells need)

micro: Fe (borderline), Cu, Na, Mg, Mn

Front 2

How to name cell metabolism

Back 2

Chemo/photo (chemical/light for energy)

organo/litho (organic/inorganic e- source)

hetero/auto (organic/inorganic carbon source)

Front 3

What metabolism are humans?

Back 3

Chemoorganoheterotroph

Front 4

Name metabolism of E. coli?

Back 4

Chemoorganoheterotroph

Front 5

Name metabolism of cyanobacteria?

Back 5

photolithoautotroph

Front 6

Only combo of metabolism that doesn't exist (probably)

Back 6

chemoorganoautotroph (chemical energy source, organic e- source and inorganic carbon source) (why would you break down C for energy and then use sunlight for carbon source)

Front 7

Effect of nutrient conc. on bacterial growth

Back 7

Higher conc. makes the rate of growth be higer, but it will level off sooner to a rate near zero.

Front 8

2 types of aerobic microbes and definitions

Back 8

Obligate: require O2

microaerophile: grow best in low levels of O2

Front 9

3 types of anaerobic microbes and definitions

Back 9

aerotolerant: aren't harmed, don't use it

obligate: cannot grow when O2 is present

Facultative: Can grow in absence, but grow better with O2 present.

Front 10

catalase test (what is it?)

Back 10

tests for catalase with hydrogen peroxide, if catalase is present h2o2 will turn into water and oxygen (bubbles).

Front 11

water availability, number that bacteria need, how is it defined?

Back 11

aw, pure water has value of 1.0, most bacteria need >0.9, is defined as pressure of air in equilibrium with substance/ " " of water

Front 12

Why does water move into cytoplasm? What will make it flow out?

Back 12

Cyto tends to have a high solute conc. than external enviro

If enviroment is hypotonic (lower solute conc. in cell than enviro) water will flow out.

Front 13

How can water loss be prevented in hypotonic sln?

Back 13

Pumping inorganic ion from enviroment

Synthesis of organic solutes

Front 14

Temperature's effect on cells (3)

Back 14

Effects macromolecular structure, membrane fluidity, enzyme fxn

Front 15

What are psychrophiles, and their min/optimum/max temps

Back 15

Microbes which prefer cold temperatures, 0/15/20 celcius

Front 16

What is pyschrotolerance, found where?

Back 16

Mesophiles which are able to grow ~0C, optimum growth is 20-40C found in soil, in your fridge

Front 17

Hyperthermophiles, found where and at what temps?

Back 17

Found in boiling springs, water heaters, hydrothermal vents, optimum temps are 50-350C

Front 18

Hyperthermophilic adaptations (4)

Back 18

amino acid subs to produce heat tolerant folds

inc. in ionic bonds between acidic and basic residies

certain solutes stabilize proteins

Modifications in cyto mem (mono layer instead of saturated bilayer)

Front 19

2 states of media and advantages

Back 19

solid (agar) - polysac from algae, gels @ 37C, rarely degraded by microbes, solidifying agent

liquid (broth)

Front 20

2 types of media, definition

Back 20

Complex - unknown chemical comp

Defined - known " "

Front 21

3 types of specialized media, uses and an example

Back 21

selective - isolation of microbes with spec. properties (brilliant green agar)

differential - allows for certain microbes to be recog based on visual cues (EMB agar)

enriched - increase population of microbes with spec. property (MacConkey Agar)

Front 22

3 ways of obtaining pure culture

Back 22

streak/spread/pour plate

Front 23

Direct counting adv./disadv

Back 23

adv: cheap, fast and easy

dis: can't differentiate between viable/dead cells

Front 24

Viable cell count method, which dilution to count?

Back 24

Do a series of 10x dilutions, spread plate all, incubate and count plate with 25-250 colonies

Front 25

How to conc. cells from a dilute sample?

Back 25

use filters with very small holes, all small water molecules will go through but the bacteria will stay

Front 26

What is turbidity, what is used to measure it?

Back 26

Turbidity is the amount of light that a substance absorbs, measured with a spectrophotometer.

Front 27

(Dis)advantages of spectrophotometer

Back 27

adv: cheap, fast, easy

dis: rough measure, doesn't distinguish between living/dead cells.

Front 28

4 phases of growth curve

Back 28

lag (preparing for growth, making proteins for replication)

log (growth is constant and exponential)

stationary (replication rate = death rate)

death phase (nutrient are depleting, cells are dying at steady rate)

Front 29

measuring live cells with spectrophoto (turbidity) over time vs. actual differences on curve

Back 29

turbidity starts off higher than viable cells, caps off earlier as it cannot read limits so close to 1, stays higher in death phase

Front 30

def: generation time

Back 30

time to double the population in exponential phase

Front 31

def: growth phase

Back 31

number of generations per unit time (inverse of gen. time)

Front 32

def: growth yield

Back 32

The max pop density and/or amount of cellular material produced by the culture

Front 33

purpose of using continuous culture, how is it done

Back 33

Used to keep microbes in exponential growth (to harvest products)

done by constantly pumping out and in nutrients/waste

Front 34

Microbial filtration uses, made of (pore sizes)?, problems

Back 34

Used to seperate microbes from field sample, made of polymer and have pore size of 0.2 or 0.45 micron, can use 10-100nm for viruses too

problems include large particles clogging and needing high pressure for viscous liquids

Front 35

What is depth filter, purpose?

Back 35

Fibrous sheet made of paper fibres randomly distributed, used as a "pre-filter"

Front 36

conventional membrane filter consists of?, pore size, uses

Back 36

made of cellulose acetate or " " nitrate with variable pore size (non-uniform), used for sterilization

Front 37

Nucleopore filters , uses, pore size, how its made?

Back 37

Used for microscopy, has uniform pore size, made by radiation damage, makes cracks which are enlarged by chemical "etching"

Front 38

Temp. manip. uses/problems

Back 38

used to denature proteins/nuc acids, kills most microbes, can be used with an autoclave to prevent fluids from evap

problems lie with hyperthermophiles, endospores and materials which cant be heated

Front 39

What is an autoclave, how is eff determined

Back 39

machine which inc. pressure and temp to sterilize media (121C, 15 psi)

eff. determined by destruction of endospores, vegatative cells

Front 40

pasteurization purpose, (dis)advantages, how is it done?

Back 40

Destroys pathogens, kills 90-99% of microbes, inc. shelf life

does not sterilize, keeps flavour

done by heating to high temp for short period of time (eg 72C for 15s and then rapid cooling)

Front 41

EM raditation sterilization, method and uses

Back 41

samples bombarded with UV rays of 260-280 nm, damages DNA via formation of thymine dimers

exploited to control microbial growth on non-living surfaces/water

Front 42

Radiation sterilization uses, (dis)advantages

Back 42

damages proteins and DNA (double strand breaks, e- stray)

Used in medical supplies/drugs/labware, food, tissue for grafting

adv are higher energy, better pen

disadv are cost/hazard, limited to industry

Front 43

3 types of antimicrobial action and effect on (viable) cell count

Back 43

bacteriostatic, inhibits growth, no decline in cell count

bacteriocidal: kills cells, doesnt dec. total cell count

bacteriolytic: makes cells lyse, dec both total and viable cell count

Front 44

2 types of chemical control

Back 44

disinfectants: used on non-living surfaces to kill infectious microbes

antiseptics: used on living tissue to kill infectious microbes (usually topically)

Front 45

5 properties of good microbe killer

Back 45

wide range of targets, isnt corrosive/toxic, doesnt leave residue/fumes, cheap, temp stable

Front 46

How to choose method? Qs to ask? (5)

Back 46

What microbe are present, #, endo?

All need to die?

What object is treated, worry about toxicity?

if using phys. method, how long is needed?
if chem. method, how powerful/long needed?

Front 47

Measuring effectiveness method

Back 47

Decimal reduction time (D value), time req. to kill 90% of microbes under spec. conditions