Chapter 6 Flashcards by nestor rios

Microbial growth

Orderly and permanent increase of the mass of an individual or a population of microbes.

How well did you know this?

Not at all

Perfectly

Reproduction

Is an increase in the numbers of individuals and can be independent of growth, although the result of reproduction is usually growth.

How well did you know this?

Not at all

Perfectly

Growth Requirements

Nutrients, - carbon, oxygen nitrogen and hydrogen

How well did you know this?

Not at all

Perfectly

Chemical and energy requirements

Nutrients - sources of carbon, energy and electrons

How well did you know this?

Not at all

Perfectly

Chemical and energy requirements 2 - groups of organisms source of carbon

-Autotrophs -heterotrophs

How well did you know this?

Not at all

Perfectly

Chemical and energy requirements 2 - groups of organisms

chemotrophs - phototrophs

How well did you know this?

Not at all

Perfectly

Physical requirements temperature

Effect of temperature on proteins - very high temp can cause denaturing Effect of temperature on membrane of cells and organelles -if too low, membranes become rigid and fragile -if too high, membranes become too fluid

How well did you know this?

Not at all

Perfectly

Effects of temperature on bacterial growth

Psychrophiles: “cold lovers” grow at -5C to 20C Mesophiles: “middle-loving”, grow at 15C-45C Thermophiles: “heat-lovers”, grow at 45C-80C

How well did you know this?

Not at all

Perfectly

Physical requirements: pH

Neutrophils - normal Range (6.5-7.5) Acidophiles - best grown in acidic habitats Alkalinophiles - live in alkaline soils and water

How well did you know this?

Not at all

Perfectly

Acidophiles

Grow best in acidic habitats

How well did you know this?

Not at all

Perfectly

Alkalinophiles

Live in alkaline soils and water

How well did you know this?

Not at all

Perfectly

Isotonic solution

No bet movement of water

How well did you know this?

Not at all

Perfectly

Hypotonic solution

War will move into the cell (cell swells up and can lyse)

How well did you know this?

Not at all

Perfectly

Hypertonic solution

Water moves out of the cell (cell shrinks, plasmolysis)

How well did you know this?

Not at all

Perfectly

Hydrostatic pressure Barophiles

Live under extreme pressure. Depends on pressure to maintain shape

How well did you know this?

Not at all

Perfectly

O2 requirements Obligate Aerobe

O2 is essential

How well did you know this?

Not at all

Perfectly

Obligate Anaerobes

O2 is deadly

How well did you know this?

Not at all

Perfectly

Radical

Oxydation

How well did you know this?

Not at all

Perfectly

Superoxide Radical (SOR)

Extremely toxic to living cells

How well did you know this?

Not at all

Perfectly

Superoxide dismutase (SOD)

Enzyme that neutralizes SOR -produced by all organisms in the presence of O2. SOD coverts superoxide radical to hydrogen peroxide (H2O2) which is also toxic

How well did you know this?

Not at all

Perfectly

2 enzymes that naturalize Hydrogen Peroxide

Catalase Peroxidase

How well did you know this?

Not at all

Perfectly

Catalase

presence of this enzyme in an organism can be detected by applying hydrogen peroxide to a culture (on solid media) and observing presence of bubbles.

How well did you know this?

Not at all

Perfectly

Peroxidase

no bubbles reaction doesn’t produce gaseous oxygen, no bubbling and be seen when applying hydrogen peroxide

Obligate Aerobes

require oxygen for growth

Facultative Anaerobes

can grow with or without oxygen (prefers CO2 than oxygen)

Obligate Anaerobes

cannot tolerate molecular oxygen (prefers CO2)

An organism growing at the top of a broth is most likely to be...

Anabolism seases because of...

insufficient nitrogen

Nitrogen is acquired from...

organic and inorganic nutrients

All cells recycle nitrogen from

amino acides and nucleotides

Nitrogen fixation by certain bacteria is...

essential to life on earth

Other Chemical Requirements

Phosporus Sulfur Trace elements - small amounts of zinc, manganese, chromium, Growth Factors - Necessary organic chemicals that cannot be synthesized by certain organisms

Vit/Min are?

Cofactors

Cultures composed of cells arising from a sing progenitor called a

CFU - one species aka pure culture

Aseptic technique prevents contaimination of

sterile substances or objects

2 common isolation techniques

- streak plate - Pure plates

most microorganisms in nature are found in

mixed cultures

Isolation of colonies is done using what technique

steak plate technique

Which technique prevents contamination of sterile substances or objects

Aseptic Technique

Each isolated colony begins as a single bacterium called:

CFU

Broths is used for what?

rapid growth

Maintenance of cultures are stored in

Slants

a synthetic or complex medium can be solidified using agar

Solid Media

Usually .5% agar, used for motility studies (SIM medium)

Semi-solid media

not agar, but broth; used for propagation of cultures

Liquid Media

nutrient material prepared for the growth of microorganisims in the laboratory ( must initially be sterile)

Culture media

made of known amounts of chemicals

synthetic (or defined) medium

some ingredients are of unknown composition or amount (extracts of plants, yeast or meat). known as? - Nutrients broth / TSA - Tryptic soy broth (TSB)

Complex medium

A culture intended to be kept for a long period of time is best kept in a...

Agar Slant

Generial Media

provies basic needs of organisms

encourages the growth of certain organism while discouraging the growth of others:

Selective medium

Selective for Gram -

McConkey selective and differential medium

Selective for Gram +

Columbia

distinguishes between different groups of bacteria - the media contains constituents which cause an observable change ( color or pH)

Differential Medium

Differential Medium that caintains lactose and neutral red, lactose

MacConkey Gram negative -

binary fission produces two identical cells, each with one full chromosome

Bacterial division