Micro - FINAL FSW

Eukarya includes all of the following EXCEPT

a. viruses.

b. protists.

c. fungi.

d. plants.

VIRUSES (these are acellular)

Viruses are neither prokaryotic nor eukaryotic.

They are acellular entities, meaning they are not made up of cells like prokaryotes (such as bacteria) or eukaryotes (such as protists. fungi, plants, and animals)

Robert Koch

proved that bacteria can cause disease

he came up with Koch's postulates, which is a method to show disease transmission

Fleming

discovered penicillin

Pasteur

discovered the cause of fermentation saving the wine industry.

Lister is associated with

aseptic surgery - Joseph Lister (think of Listerine and it's purpose as an antiseptic)

Jenner conducted an experiment that eventually led to one of the following concepts:

Vaccination

The process of using just enough heat to kill most (but not all) of the bacteria that cause spoilage in a beverage was developed by

Pasteur

think of milk

The measure of the light-bending ability of a medium is the

refractive index.

The ability of the lenses of a microscope to distinguish fine detail and structure is called

resolution.

Which microscope uses an opaque disk to block light that would enter the objective lens directly producing a light or white specimen on a dark background?

Darkfield microscope

Which microscope uses an ultraviolet light source to produce brightly colored object against a dark background?

Fluorescence microscope

Before microorganisms are stained, MOST appear ________ when viewed with brightfield microscopy.

colorless

The chromophore of basic dyes is ________ and is ________ to MOST types of bacteria.

positively charged; attracted

Which one of the following is NOT a kind of staining technique?

Selective

The process of fixing a slide attaches the microorganisms while simultaneously

killing the organisms.

This is part of the process, to attach the cells to the slide and also to kill the organisms that are there preserving them to the best of our ability.

A technique used for preparing a slide with colorless bacteria against a colored background is called

negative staining.

Negative staining uses an acidic dye that is repelled by the negatively charged bacterial cells so the background is colored while the cells remain colorless.

What is the mordant in the gram stain?

Iodine

Capsules are stained using a(n)

negative stain.

A bond formed from the attraction between ions of opposite charge is called a(n)

ionic bond.

ions are charged particles that form when electrons are gained or lost. The attractions between them (opposites attract) is an ionic bond

Which of the following is formed by the sharing of electrons between atoms to fill an electron shell?

Covalent bond

sharing electrons

Which of the following statements is FALSE for prokaryotes?

They are multicellular organisms.

All prokaryotes are single celled.

Only eukaryotes can be multicellular.

prokaryotes

- lack organelles (such as nuclei).

-Their cell walls contain peptidoglycan.

- binary fission.

-They can associate in pairs, chains, clusters or other groupings.

Which level of protein structure refers to the overall three-dimensional structure of a polypeptide chain?

Tertiary structure

various bonds form between the R groups (radical or variable groups) giving a polypeptide its three-dimensional shape

In addition to peptidoglycan, the cell walls of gram-positive bacteria contain

teichoic acid.

Gram-positive bacteria have a thicker peptidoglycan layer.

The layers are held together by teichoic acid.

A bacterium possessing a tuft of flagella at one end of its cell is called

lophotrichous - a tuft of flagella at one pole

Which structure protects pathogenic or infectious bacteria from phagocytosis (being engulfed by white blood cells)?

capsule

Spirochetes move by means of

axial filaments.

Which of the following is NOT a part of a flagellum?

Fimbriae

The three part of the flagellum from outside in are the filament, hook and the basal body

Which of the following structures allows a bacterial cell to survive adverse environmental conditions?

endospores

dormant structures for protection from environmental stress

Which of the following is a specific way to move materials across prokaryotic plasma membranes?

Group translocation

chemical modification to keep molecules from going back out in prokaryotic cells only

In 1928, who observed that the growth of bacteria was inhibited on a Petri plate contaminated by a mold?

Alexander Fleming

discovered penicillin

What was the first antibiotic (not antimicrobial) discovered?

penicillin

Alexander Fleming when he had a contamination on his supposedly pure-culture plate. He was observant enough to see that the growth of this organism inhibited the bacteria he was trying to grow on the plate.

Which one of the following groups of pathogens are the easiest to treat with antimicrobial agents?

Bacteria

Bacteria are different compared to our cells.

- prokaryotic, have peptidoglycan in their cell walls and 70S ribosomes unlike the majority of ours which are 80S.

-Fungi and Protozoa are eukaryotic and viruses replicate in our cells so they are somewhat more difficult to treat compared to bacteria.

One disadvantage to using broad-spectrum antibiotics is that they

destroy normal microbiota.

Broad-spectrum antibiotics will target both gram-positive and gram-negative bacteria so can also kill our normal flora.

The building of complex organic molecules from simpler ones is called

anabolism.

Anabolism is the process of using smaller molecules to build larger ones. In this process chemical bonds are formed through dehydration synthesis and energy is used. An example is photosynthesis.

What happens to enzyme activity at temperatures above optimum but before denaturation?

Enzyme activity decreases.

Enzyme activity increases with temperature until the optimum temperature is reached. After the optimum temperature the enzyme activity will decrease and too far past the optimum temperature the enzyme will denature.

When every enzyme's active site is reacting with a substrate, it is called __________.

saturation

Saturation is when every enzyme's active site is reacting with a substrate. In a graph the line for enzyme activity will plateau or level off flat.

Which of the following is CORRECTLY matched?

Glycolysis – can occur with or without the presence of oxygen

Glycolysis – glucose is broken into pyruvic acid, 2 ATP are made, NADH (electron carrier) molecules are made, can occur in the presence or absence of oxygen

In anaerobic respiration, the final electron acceptor is __________.

an inorganic molecule other than oxygen

The word anaerobic means without oxygen and oxygen is not organic, so an inorganic molecule other than oxygen seems to be the most logical.

Which of the following is true regarding fermentation?

Does not require oxygen

Fermentation is a pathway that occurs without oxygen. It still starts with glycolysis and then goes a different pathway to produce alcohol or citric acid. It only makes 2 ATP from glycolysis as the energy is stored in the end products.

________ use electrons from reduced inorganic or organic compounds as a source of energy and CO2 as a source of carbon.

Chemoautotrophs

A substance that dissociates into H+ and Cl- in water is an example of a(n)

acid

An acid is a substance that breaks down increasing the H+ concentration.

pH stands for potential hydrogen and the higher the H+ concentration the more acidic.

H+ and OH- concentrations are equal at neutral pH (7),

H+ concentration is higher than OH- acidic (pH less than 7) H+ concentration is lower than OH- basic (pH greater than 7).

A bacterial cell that grows best at pH 7 is a __________.

neutrophile

pH 7 is neutral- neutrophiles.

pH less than 7 is an acid-acidophile.

pH greater than 7 is a base (alkaline)- alkaliphile.

A psychrophile has an optimal growth temperature in which of the following environments?

supercooled waters

(cold-loving)

Organisms that require high salt concentrations for growth are called

obligate halophiles.

Halo- means salt

Obligate means “requires”

Facultative can be flexible so they can grow in salt, but do not require it.

Some microorganisms use gaseous nitrogen directly from the atmosphere in a process called

nitrogen fixation.

An organism that uses oxygen when present but can grow without oxygen is called a(n)

facultative anaerobe.

Facultative means flexible and these organisms will use oxygen in aerobic cellular respiration for more efficient ATP production, but will convert to fermentation when oxygen isn’t present even though efficiency is lower.

In which one of the following growth phases is there intense activity preparing for population growth, but no increase in population?

Lag phase – acclimation or adaptation, but no growth

Log phase – logarithmic or exponential growth where each cell is dividing

Stationary phase – cell division (growth) = cell death

Death phase – cells are dying more than they are dividing

In the stationary phase,

the number of microbial deaths is equal to thenumber of new cells formed.

Which type of medium suppresses the growth of unwanted bacteria and encourages the growth of desired microbes?

Selective media

selects for” or chooses what will grow

A culture medium made of extracts from yeasts, meat, or plants is a ________ medium.

complex

contains extracts or digests of food sources (cannot determine an exact chemical formula) that vary slightly from batch to batch

The removal or destruction of all living organisms is called

sterilization

the removal or destruction of all living microorganisms including endospores

The destruction of vegetative pathogens on inanimate objects is called

disinfection

destruction of vegetative pathogens on an inanimate surface

Which treatment is intended to lower microbial counts on eating and drinking utensils to save public health levels?

Sanitization

lower microbial counts to safe public health levels; minimize the chances of disease transmission

The absence of significant contamination on an object or in an area is referred to as

aseptic - an object or area is free of pathogens

Commercial sterilization is a limited heat treatment to destroy

Clostridium botulinum endospores.

Botulism is a serious infection that can be associated with canned goods. The organism Clostridium botulinum produces endospores that could survive improper heat treatment and since it is anaerobic they will germinate in the can and the vegetative cells will produce a toxin that can be fatal to humans.

To sterilize heat-sensitive solutions such as culture media, enzymes, and vaccines, one should use

filtration

Filtration is passing the liquid through a filter with pore sizes smaller than the average bacterial cell so they are trapped on the filter and the liquid coming through is sterile.