Microbiology--Test 1

Front 1

Why are Archaea given their own domain?

Back 1

Archaea are different from eukaryotes in that they are prokaryotic. They are different from bacteria in that the cell walls of archaea lack peptidoglycan and are instead composed of other chemicals. Also, there are no known archaea that cause disease, and this cannot be said for bacteria.

Front 2

Francesco Redi

Back 2

kept meat away from flies, and no maggots were found. Started to doubt spontaneous generation.

Front 3

Antoni van Leeuwenhoek

Back 3

made his own magnifying glass. Experimented with it until one day he put water underneath it, and discovered microbes.

Front 4

Carolus Linnaeus

Back 4

developed the taxonomic system

Front 5

John T. Needham

Back 5

tried to prove spontaneous generation by boiling beef gravy and sealing it with a cork, then observing days later microorganisms in it

Front 6

Lazzaro Spallanzani

Back 6

boiled infusions for an hour, then melted the vials closed. No microbe growth was observed. Concluded that Needham didn’t heat his vials well enough, didn’t seal them tightly enough, that microorganisms exist in the air, and that living things always arise from other living things

Front 7

Louis Pasteur

Back 7

made swan necked flasks and boiled water in them. The swan necked flasks did not grow microbes, showing that microbes were in the air when he broke the neck of the flasks and there were microbes days later. Also proved that microbes make fermentation happen, giving us the gift of alcohol

Front 8

Robert Koch

Back 8

Postulates. Agents must be found in every case of disease and be absent from healthy hosts. Agent must be grown outside the host. Agent is introduced to healthy host, and host gets disease. Agent must be found in diseased host

Front 9

Florence Nightingale

Back 9

instrumental in setting antiseptic standards in hospitals

Front 10

Edward Jenner

Back 10

the cowpox/smallpox guy (vaccines)

Front 11

How do eukaryotes compartmentalize their cytoplasm?

Back 11

They have numerous other internal membranes that compartmentalize cellular functions. These compartments are membrane-bound organelles.

Front 12

How to prokaryotes compartmentalize their cytoplasm?

Back 12

Bacteria have cytosol, which is the liquid portion of cytoplasm. In this inclusions are found. Inclusions can be used to compartmentalize the cell.

Front 13

Glycocalyx

Back 13

sticky chemicals outside of some cells that protect it from drying and also can play a role in survival

Front 14

Flagella

Back 14

long structures that extend beyond the surface of a cell and propel the cell through its environment. Composed of a filament, hook, and a basal body

Front 15

Fimbriae

Back 15

smaller than flagella, used to move across a surface.

Front 16

Pili

Back 16

used to transfer DNA form one cell to another via a process called conjugation.

Front 17

Chemotaxis, and the organelle responsible for it

Back 17

Chemotaxis is the movement of a cell toward or away form a certain chemical (stimulus). Movement toward a favorable stimulus is called positive taxis, and movement away from an unfavorable one is called negative taxis.

FLAGELLA

Front 18

What are enzymes and how do they work.

Back 18

Enzymes are catalysts that lower what is called activation energy needed for a chemical reaction to happen. This makes it so that it takes less energy for a reaction.

Front 19

Competitive and non-competitive inhibitors

Back 19

Inhibitors block an enzymes activation site. Competitive inhibitors are shaped so that they fit into the enzymes activate site and prevent normal substrate from binding. Non-competitive inhibitors bind to an allosteric site elsewhere on the enzyme, which distorts the shape of the actual active site.

Front 20

Pentose phosphate pathway

Back 20

Purpose is a way to produce energy that is different than glycolysis. It reduces two molecules of NADP+ to NADPH and nets a single molecule of ATP from each molecule of glucose.

Front 21

Entner-Doudoroff Pathway

Back 21

Substitute for glycolysis as well. It catabolizes glucose to pyruvic acid using different enzymes from those used in either glycolysis or the pentose phosphate pathway

Front 22

Embden-Meyerhof Pathway

Back 22

Also more commonly known as glycolysis. It is the first step in the catabolism of glucose via both respiration and fermentation. In general, it involves splitting a six-carbon glucose molecule into three-carbon sugar molecules. When these three-carbon molecules are oxidized to pyruvic acid, some of the energy is released and stored in molecules of ATP and NADH. Cells can use many of the intermediate molecules in glycolysis as precursor to metabolites.

Front 23

Fermentation

Back 23

Fermentation is the partial oxidation of sugar to release energy using an organic molecule from within the cell as the final electron acceptor. Essentially the main function of fermentation is to regenerate the coenzyme NAD+, so that glycolysis can continue to break down glucose and produce ATP in anaerobic conditions when no oxygen is available.

Front 24

does aerobic respiration require oxygen

Back 24

yes

Front 25

does anaerobic respiration require oxygen

Back 25

no

Front 26

Final electron (hydrogen) acceptor for aerobic respiration

Back 26

oxygen

Front 27

Final electron (hydrogen) acceptor for anaerobic respiration

Back 27

NO3, SO4, CO3, or externally acquired organic molecules

Front 28

Potential molecules of ATP produced per molecule of glucose (AEROBIC)

Back 28

38 in prokaryotes, 36 in eukaryotes

Front 29

Potential molecules of ATP produced per molecule of glucose (ANAEROBIC)

Back 29

2-36

Front 30

Peptidoglycan and its role in Gram+ vs Gram-

Back 30

In a Gram positive bacterium, there is more peptidoglycan, which retains the colorizer during the staining process. In contrast, a Gran negative bacterium has a very thin peptidoglycan layer, so it will not retain the stain.

Front 31

Gram staining

Back 31

It is simply a method used to differentiate between two large groups of bacteria, the Gram positive and the Gram negative

Front 32

Cell walls of Gram positive and Gram negative cells

Back 32

Gram positive cell walls have a relatively thick layer of peptidoglycan that also contains chemicals called teichoic acids. It has a negative electrical charge due to these acids. Gram negative cell walls have a very thin layer of peptidoglycan but outside this is another layer composed of two different layers. The inner one is composed of phospholipids and proteins, and the outer layer is composed of lipopolysaccharide.

Front 33

Techniques to classify bacteria

Back 33

Bacteria is classified into groups called taxa. This is done using a system called taxonomy. A bacteria is first sorted into a kingdom, then a phylum, class, order, family genus, and species, respectively. (PAGE 112)

Front 34

Oil immersion method

Back 34

Oil immersion lens increases the magnification but also the resolution. Resolution is the ability to distinguish objects that are closer together. Light refracts as it travels from air into glass and also from glass into air. Placing immersion oil between the slide and the lens stops the refraction of light and makes the light travel at uniform speed through the slide and the oil and the lens.

Front 35

Biofilms and their importance

Back 35

Biofilms are complex relationships among numerous microorganisms, often different species, attached to surfaces such as teeth, rocks in streams, and other things. They are the primary residence of microorganisms in nature.

Front 36

Quorum sensing

Back 36

Microbes secrete quorum sensing molecules that act to communicate number and types of cells among members of a biofilm. When the density of microorganisms increases, the concentration of quorum sensing molecules also increases. Once the binding exceeds a certain threshold, the expression of previously suppressed genes is triggered, and the result is that the microorganisms have new characteristics, such as production of enzymes, changes in cells shape, and the ability to form and maintain biofilms.