Microbiology Final

Known for disproving spontaneous generation. His work on fermentation and pasteurization revolutionized the understanding of microbial processes.

Louis Pasteur

Introduced aseptic techniques in surgery, significantly reducing infections

Joseph Lister

Established a method to link specific microbes to specific diseases.

Robert Koch

Discovered penicillin, the first true antibiotic, which transformed medical treatment of bacterial infections.

Alexander Fleming

DNA is typically a single, circular chromosome that is not enclosed within a nuclear membrane. ells are typically 0.2 to 2.0 micrometers in diameter, much smaller than eukaryotic cells.

Prokaryotes

Generally lack membrane-bound organelles such as nuclei, mitochondria, and chloroplasts. Some bacteria have microcompartments, but these are not enclosed by a phospholipid bilayer.

Prokaryotes (4)

Cell walls contain peptidoglycan, a complex polysaccharide, which provides structural support.

Prokaryotes (2)

Usually reproduce by binary fission, a simpler process than eukaryotic mitosis.

Prokaryotes

Cells are typically 0.2 to 2.0 micrometers in diameter, much smaller than eukaryotic cells.

Prokaryotes (3)

Have a true nucleus enclosed by a nuclear membrane, containing multiple linear chromosomes associated with histones.

Eukaryotes (2)

They possess membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi complex, lysosomes, and sometimes chloroplasts, which perform specific functions within the cell.

Eukaryotes

Cell walls are chemically simple, often composed of cellulose or chitin.

Eukaryotes (3)

Cells divide by mitosis, ensuring that each daughter cell receives an identical set of chromosomes.

Eukaryotes

Cells range from 10 to 100 micrometers in diameter.

Eukaryotes (4)

Differences between Prokaryotes and Eukaryotes

1. Prokaryotes do not have a nucleus.

2. Prokaryotes are much less complex.

3. Prokaryotes are generally smaller.

What are the 3 domains?

Bacteria, Archaea, Eukarya

What are the 5 kingdoms?

Monera, Protista, Fungi, Plantae, Animalia

The highest level of taxonomy hierarchy, which groups organisms based on fundamental differences in their cell structure.

Domain

Within each domain, organisms are further divided into_________.

Kingdom

List the taxonomic hierarchies...

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

In Binomial nomenclature, each organism is assigned a ________name and a specific _________ name.

genus, species

In Binomial nomenclature, both names are ________ or. For instance, Escherichia coli

italicized, underlined

In Binomial nomenclature the genus name is __________ , while the species name is ____________ .

capitalized, lowercase

What is total magnification using a Compound Light Microscope?

the ocular lens (10x) times objective lens

What are the elements of good microscopy?

resolution, magnification, contrast, illumination

What does TEM stand for?

transmission electron microscope

When would you use a TEM?

small samples at near-atomic resolution

What does SEM stand for?

scanning electron microscope

When would you use a SEM?

if you need to look at a relatively large area and only need surface details

What is the purpose of staining?

Increase Contrast, Highlight Structures, Differentiation

What is gram staining?

Gram staining is a procedure by which bacteria can be classified by the ability of the cell wall to absorb a crystal violet dye, followed by a red safranin counterstain.

What color is gram positive bacteria?

purple

What color is gram negative bacteria?

Turns pink, can't be stained, THIN cell wall

What is purpose of capsule staining?

to reveal the presence of the bacterial capsule

What is the purpose of acid-fast staining?

To differentiate cells that contain mycolic acid from those that don't

What is the initial stain in the Schaeffer-Fulton endospore staining method?

Malachite green

What is the counterstain in the Schaeffer-Fulton endospore staining method?

Safranin

In the Schaeffer-Fulton endospore staining method, endospores appear _______, while the rest of the cell is_____.

green, pink

What kind of cell walls do gram positive (purple) bacteria have?

thick peptidoglycan and teichoic acids

What kind of cell wall do gram negative (pink) bacteria have?

Thin Peptidoglycan Layer with an outer lipopolysaccharides (LPS) membrane

What makes gram negative bacteria more virulent?

the LPS outer layer more resistant to antibiotics, have porins restrict entry of harmful substances and they produce endotoxins

Coccus (cocci)

spherical

diplococci

cocci growing in pairs

streptococci

bacteria that form a chain

staphylococci

grape-like clusters

Bacillus (Bacilli)

rod shaped

diplobacilli

pairs of bacilli

streptobacilli

chains of bacilli

Spirillum

spiral shape

Vibrio

comma shaped

peritricious

flagella all around

Monotricious

one flagellum

lopotricious

several flagellum on one side

amphitricious

flagellum on both ends

What are mycobacterium?

have cell walls containing lipids constructed from mycolic acids- prevents dyes from binding to cells

What is another name for mycobacterium?

acid-fast bacterium

Acid fast bacteria

Contains mycolic acid, making it resistant to chemicals and dehydration.

What are mycoplasma?

bacteria that lack cell walls

What are archaea?

Primitive bacteria usually living in extreme environments

What bacteria have atypical cell walls?

Mycobacterium, Mycoplasma and Archae

gram positive

purple, thick peptidoglycan cell wall, techoic acids

gram negative

pink, thin peptidoglycan, LPS lipid layer

What is importance of bacterial cell walls?

prevents osmotic lysis, made of rigid peptidoglycan

How do capsules help protect bacteria?

Prevent phagocytosis by white blood cells

How do fimbrae help bacteria?

attachment

What is function of pili?

facilitate transfer of DNA from one cell to another

Plasma membrane of bacteria.

phospholipid bilayer, selectively permeable

How does the outer LPS layer affect bacteria?

protect from antimicrobial chemicals, more difficult to kill than gram-positive bacteria, Infections treated differently than with gram-negative bacteria

Characteristics of bacterial chromosome

-Single circular strand of DNA

-in area called nucleoid

-DNA tightly coiled around basic protein molecules to fit

Characteristics of Ribosomes

made of RNA and protein

Importance of inclusions

nutrient and energy reserves,

What are endospores?

cells in dormant stage

What are the characteristics of endospores?

dehydrated, resistant to, heat, chemicals

What is the stimulus for endospore formation?

depletion of nutrients, especially carbon and nitrogen

The cell _____ can be composed of three layers: the cell membrane, the cell wall, and the outer membrane.

envelope

Enzymes are

biological catalysts

What is a substrate?

any substance with which an enzyme react

What is competitive inhibition?

the shape of the inhibitor is similar to that of the substrate that usually binds with the enzyme and can block the active site preventing a reaction

What is non-competitive inhibition?

this is where an inhibitor binds to an enzyme site other then the active sight and changes the shape of the active site meaning the substrate can no longer bind to the active site and no reaction can occur

What is the active site?

Region on enzyme where substrate binds

What are allosteric sites?

specific location on an enzyme where a noncompetitive inhibitor can bind changing the enzyme's shape and function

What is a cofactor?

nonprotein components that assist enzymes in catalyzing reactions

What is a coenzyme?

a cofactor that is an organic molecule

What are the three basic catabolic pathways?

1. aerobic respiration

2. anaerobic respiration

3. fermentation

How many ATPs produced in Glycolosis?

2 ATPs

Glycolosis is part of which metabolic pathway?

aerobic respiration, anaerobic respiration, fermentation

Krebs cycle produces how many ATPs?

2 ATPs

Krebs cycle is part of which metabolic pathway?

aerobic respiration, anaerobic respiration

How many ATPs produced in Electron transport chain (ETC)?

about 34

How many ATPs produced in aerobic respiration?

36-38

What is the electron receptor of anaerobic fermentation?

Non O2 not oxygen

What is electron acceptor of fermentation?

organic compound

What is difference between fermentation and respiration?

both start with glycolysis but fermentation does not go through Krebs cycle or the electron transport chain thus yielding a lot less ATPs.

What is the electron acceptor of aerobic respiration?

Oxygen

What are the pathways of respiration

Glycolosis, Krebs cycle, Electron transport chain

What is the biproduct of aerobic respiration?

CO2

Does fermentation require oxygen?

No, anaerobic

What is the energy and carbon source of photoautotrophs?

energy source is light, carbon source is CO2

What is the energy and carbon source of Photoheterotrophs

Energy from light, carbon from organic compounds

What is the energy and carbon source of chemoautotrophs?

energy by oxidizing inorganic substances, needs only carbon dioxide as a carbon source