Microbiology Ch. 22 (powerpoint notes/vocabulary)

pH of a human body

7.4

Peritrichous bacterium

A bacterial cell with flagella distributed over its entire cell

Solution

A type of homogenous mixture in which the particles of one or more substances (the solute) are distributed uniformly throughout another substance (the solvent).

Organisms in which of the following kingdoms do NOT have a cell wall?

Animalia

Facultative bacterium

Bacteria capable of adjusting to changes in environmental oxygen levels.

Coccus

Bacteria shaped like a sphere

Microaerophilic organisms

Bacterium that requires small amounts of oxygen. Need only about 2%-10% to survive.

Why do yeast infections occur more frequently in the vagina than other areas of the body?

Because the vagina is more acidic and supports the growth of fungi that cause yeast infections.

Aerotolerant bacterium

Can grow in the presence or absence of oxygen. Completely indifferent to oxygen levels. Do not gain any benefit from its presence

Which of the following is NOT a mechanism by which bacteria achieve motility or adherence?

Capsule

Which of the following types of organisms would be most likely to survive in the dry air of the American Southwest?

Fungi

Which of the following is the reason for sporulation in bacteria?

It is a means of survival

Which of the following are bacteria that prefer moderate temperatures and grow best between 25o C and 40oC (77o-104oF)?

Mesophiles

Name the five (5) kingdoms

Monera, Protista, Fungi, Plantae, Animalia

Which of the following microorganisms can grow and reproduce outside a host cell?

Mycoplasmas

Which of the following terms describes the need for viruses, viroids, and prions to live only in a host cell due to their lack of internal structures that produce energy or utilize nutrients?

Obligate Parasites

Which of the following refers to organisms that only survive on dead or decaying organic matter?

Obligate Saprophytes

Two Major Cells Types

Prokaryotic and Eukaryotic.

Streptobacilli

Rod shaped bacterial cells appearing in a chain arrangement pattern

Which of the following is not characteristic of gram-positive bacteria?

They have less complex nutritional requirements

Light Requirements

Yeasts and molds have no chlorophyll, do not need sunlight to produce energy, and therefore prefer dark areas for optimum growth. Cyanobacteria convert light into a food source, therefore they thrive in sunlight. Ultraviolet light can destroy many bacteria (but NOT endospores!!)

Peritricuous Bacterium

a bacterial cell having flagella distributed over its entire cell

Monomorphic

a bacterium capable of having only one shape

Thermophiles

a bacterium or other microorganism that grows best at higher than normal temperatures (HOT)

Pseudomonas

a genus of bacteria that is commonly associated with the secondary infections in burn patients.

Binary Fission

a method of asexual reproduction in bacteria in which the cell splits into two parts, each of which develops into a complete individual

Antagonism

a mutual opposition or contrary action. Refers to the inhibition of one microorganism's growth by presence of another

Bacillus

a rod shaped bacterial cell

Hypotonic Solution

a solution that has less solute and more water than another solution.

Glycolcalyx

a sticky gelatinous coating secreted by prokaryotes that surrounds the cell wall

Glycocalyx

a sticky, gelatinous coating that surrounds the cell wall of prokaryotic cells

Endospore

a thick-walled cell produced by a bacterium to enable it to survive unfavorable environmental conditions; resistant to antibiotics, most disinfectants and physical agents such as radiation, boiling, and drying

Cooling rate of human remains:

a. -4 degrees for the first hour after death b. -1 degree F per hour after that until room tempurate is reached. c. Can vary depending on environmental changes.

Temperature Requirements:

a. Psychrophiles b. Mesophiles c. Thermophiles d. Each organism has its own minimum, maximum and optimum temperature for growth

pH Requirements:

a. pH refers to the concentration of hydrogen ions present in the environment surrounding the bacterium ( [H+] ). b. pH scale ranges from 0 to 14. c. Bacterial cells try to maintain internal pH homeostasis

Staphylococci

bacteria cells of spherical shape, having an arrangement similar to a cluster of grapes

Spirochete

bacteria with a spiral or helical shape

Streptococci

bacterial cells spherical in shape and appearing in a chain arrangement pattern

Facultative bacteria

can adapt to differing sources of nutrition.

Methylene blue

common dye used to observe DNA or RNA in a cell

Strict Parasites

completely dependent on their host for nutrients needed to survive.

Symbiotic relationships

distinguished by the degree to which that host organism is harmed

Moisture Requirements

each organism has a maximum, optimum, and minimum amount of water necessary to sustain life.

Commensalism

exists when one organism gains some benefit, like protection or nourishment, and the host is not harmed

Psychrophiles

extremophilic organisms that are capable of growth and reproduction in cold temperatures, ranging from −20°C to +10°C.

Hypertonic Solution

has a higher concentration of solutes outside the cell than inside the cell.

Osmotic Pressure Requirements

high concentration of salt/chemical in environment, water is drawn out of the cell to balance (osmosis). Can compensate for small changes in concentration by producing various amino acids that aid in maintaining intracellular fluid levels. Applications of osmotic pressure vs. bacterial growth

Parasitism

in this relationship, the host is harmed, while the parasite receives some benefit

Flagella

long, whiplike filament-containing appendages that spin in either a clockwise or counterclockwise direction along its axis, thus propelling the bacterial cell

Obligate (strict) anaerobes

microbes that can only survive in an environment with no oxygen. Example is Clostridium perfringens (Tissue gas). Listeria and Clostridium botulinum commonly cause food poisoning.

Obligate (strict) aerobes

microorganisms that can only live in the presence of oxygen. Oxygen needed to metabolize sugars.

Synergism

occurs when the harmonious action of two microorganisms produce an effect that neither could produce alone

Cyanobacteria

one of the largest groups of autotrophic bacteria. Blue-green algae appearance.

Strict saprophytes

organisms that only survive on dead or decaying organic matter.

Morphology

refers to the size, shape and arrangement of a microorganism

Heterotrophic bacteria

requires complex organic food from a carbon source to grow and develop. Cause of numerous diseases in humans.

Autotrophic bacteria

self-nourishing bacteria capable of growing in the absence of organic compounds (Inorganic). Use light and carbon dioxide to produce food. Cause very few diseases in humans, decomposition of human remains.

Fluid Suspension Technique

technique that can be used to observe the movement of live microorganisms

Microbial Association

the different types of associations that microorganisms form with other organisms are related to both the formation of disease in humans and the decomposition of human remains.

Osmotic Pressure

the pressure required to prevent net flow of water across a semipermeable membrane.

Mutualism

two different species live in close associations to the mutual benefit of each other

Isotonic Solution

two solutions having the same osmotic pressure across a semipermeable membrane. This state allows for the free movement of water across the membrane without changing the concentration of solutes on either side of the membrane.

Binomial Nomenclature

two-part name given to an organism

Fluid Suspension Technique

used if one wants to observe the structures of microorganisms while they are alive and in motion

Smearing technique

used to observe the morphology of microorganisms; a bacterial colony culture is placed onto a glass slide and allowed to dry, the slide is then heated in order to fix the bacteria to the slide and stained in order to visualize the desired structures via light microscopy

Symbiosis

when two or more different species of organisms live together in close association

Three categories of heterotrophic bacteria:

•Strict (obligate) saprophytes •Strict (obligate) parasites •Facultative bacteria