Chapter 1: Intro to Microbiology Flashcards
What is microbiology?
The study of the microbial world
What are microorganisms?
Living organisms that include bacteria, protozoa, fungi and some algae that are not visible to the the naked eye.
cellular in structure
What is a microbe?
Includes all microorganisms along with viruses and prions
Viruses and prions are not made up of living organisms
Who is Robert Hooke?
1665 English Scientist
Who is Anthony van Leeuwenhoek?
1674 Dutch fabric merchant
What are living microorganisms?
Bacteria, protozoa, fungi, and some algae
What helped develop the scientific method?
Spontaneous generation
Who made the first “microscope” and observed animalcules?
Leeuwenhoek
Who hypothesized that invisible organisms may cause disease?
Fracastoro
Who made the first “modern microscope” and coined the word “cell”?
Hooke
What scientist created the “swan neck flask” experiment?
Pasteur
Who formulated the germ theory of disease?
Pasteur
Who discovered penicillin?
Hooke
Who studied causative agents of disease?
Robert Koch
What is the gold standard for determining disease causation?
- The same organism must be present in every case of the disease
- The organism must be isolated from the diseased host and grown in pure culture
- isolate must cause disease in healthy host
- must be re-isolated from diseased host
Who disproved Pasteur about spontaneous generation?
John Tyndall and Ferdinand Cohn
Who discovered endospores?
Ferdinand Cohn
What is etiology?
causative agents of disease
Who discovered agars?
Robert Koch
What did Robert Koch do?
- first pictures of bacteria
- staining techniques
3.use of steam to sterilize - petri dishes
- sterile lab techniques to transfer bacteria
What does zoonotic mean?
comes from animals
What are the good parts of microbes?
nitrogen fixing
carbon fixing
photosynthesis
decomposition
fermentation
bioremediation
digestion
What is nitrogen fixing?
-Process by which nitrogen gas (N2) is converted into ammonia (NH3)
-Nitrogen can then be incorporated into cellular material (amino acids-protein)
What is fermentation?
-Lactic acid producing bacteria
-Cheese, pickles, sour kraut
-Wine, beer
What is bioremediation?
-Use of microorganisms to remove toxins and pollutants from the environment
-Water waste treatment
-Oil spills
What are prokaryotes?
bacteria and archaea
What is the difference between bacteria and archaea?
Bacteria- have peptidoglycan cell walls
Archaea- don’t have peptidoglycan or cell walls
What constitutes a nomenclature name?
1) Capitalized genus
2) Lowercase species
How is prokaryotic digestion different from eukaryotic?
Prokaryotic bacteria secrete digestive enzymes out of the cell to get macromolecules and deposit pieces back into the cell.
What are bacteria?
gram positive and gram negative
What is an example of an archaea?
halophiles
What are some examples of eukarya?
Fungi, animals, plants, algae, and protozoa
What do bacteria have?
- no nuclear membrane
- cell wall/ peptidoglycan
- ubiquitous
- no membrane-bound organelles
What do archaea have?
- no nuclear membrane
- no peptidoglycan
- ubiquitous
- no membrane bound organelles
What do eukarya have?
- nuclear membrane
- no peptidoglycan
- membrane bound organelles
- non-extreme environments
What does ubiquitous mean?
can live in almost any environment
What do algae have/ do?
- single-celled and multicellular
- photosynthetic
- primarily aquatic
What do fungi have/do?
- single celled and multicellular
- degradation/fermentation
- primarily terrestrial
What do protozoa have/do?
- single celled
- found anywhere
What are some non-living organisms?
Viruses, viroids, and prions
What describes a virus?
-RNA or DNA
-protein coats
-obligate intracellular pathogen
-infect plants, animals and microorganisms
What describes viroids?
-short RNA
-no protein coat
-infect plants
What describes prions?
-protein
-transfer a misfolded protein to healthy proteins
What is the cell structure of a prokaryote?
Cell envelope
-cytoplasmic membrane
-cell wall
-possibly a capsule
What does the cytoplasmic membrane of prokaryotes contain/do?
-separates in from out
-phospholipids
-trans-membrane proteins
—gates nutrients and waste
— fluid mosaic model
-selectively permeable through simple diffusion
—gases
—water by osmosis
—small hydrophobic molecules
How does water diffuse through the cytoplasmic membrane of a prokaryote?
water moves from hypotonic to hypertonic through osmosis
How does transport work in the cytoplasmic membrane?
Transport is performed by proteins embedded in the membrane
What is transported through the cytoplasmic membrane?
enzymes and extracellular proteins
What are enzymes?
secreted to digest saccharides that the cell can take in for nutrients
What does extracellular proteins do?
used for flagella and other proteins for motility
What is NAG?
N-acetylglucosamine
What is NAM?
N-acetylmuramic acid
What are NAG and NAM similar to?
glucose
What is NAM linked by?
linked by a peptide interbridge in gram + bacteria
What is NAM linked by?
has a tetrapeptide chain that directly links in gram -
List 5 characteristics of gram-positive bacteria
- Thick layer of peptidoglycan
- Teichoic Acids
- Single inner membrane
- Gel membrane underneath peptidoglycan layer
- NAG-NAM cross bridge
List 5 characteristics of gram-negative bacteria
- Thin layer of peptidoglycan
- Porins
- Two membranes, with periplasmic space in between
- LPS (endotoxin PAMP)
- NAG-NAM direct linkage
What is lipid A?
an endotoxin which causes inflammation
Where are porins in a gram - bacteria?
in the upper membrane
Differentiate capsules, slime layers, and biofilms
A: A gel capsule is a gel-like layer for protection/adherence (whipped cream)
B: Slime layers + Capsules contain glycocalyx (sugar shell), providing uniform, strong protection. (icing)
C: Biofilm: Polymer-encased community. Many layers. (Bunker for protection) Example: dental plaque
What is the importance of pili?
Pili help bacteria adhere to specific surfaces and move on solid surfaces. They also facilitate DNA transfer. Hide close to the surface to avoid leukocytes.
What is the functions of periplasm in gram - bacteria?
-nutrient degradation
-enzyme secretion
-electron transport
-xenobiotic metabolism
has the same function as the gel-like layer of gram + peptidoglycan layer
What is LPS?
lipopolysaccharide which is also an endotoxin
What is in a LPS?
O antigen and lipid A
Where is lipid A in LPS?
Anchored in the outer membrane
Where is the O antigen in LPS?
outer portion and is variable among bacteria
What are plasmids?
Plasmids are small loops of extra DNA that aren’t part of the chromosome. Plasmids contain genes for things like drug resistance and can be passed between bacteria.
What constitutes an endospore?
Sugar + Chromosome + Protein
What key features help differentiate eukaryotic cells from prokaryotic cells?
Eukaryotic: membrane-bound organelles (mostly), nucleus, most lack cell walls, plant cell walls have chitin and cellulose, single chromosome versus multiple.
What is different about eukaryotic cytoplasmic membrane transports compared to prokaryotes?
Eukaryotes can perform endocytosis, exocytosis, and fusion with lysosomes.
What eukaryotic structure is similar to cyanobacteria?
Chloroplasts. Plants and algae have mitochondria and chloroplasts.