INTRODUCTION TO MICROBIOLOGY - Lesson 1 Flashcards
Lesson 1
1
Q
the scientific study of microorganisms
A
MICROBIOLOGY
2
Q
minute living things that individually are usually too small to be seen with the unaided eye
A
Microorganisms
3
Q
Types of Microorganisms
A
- Bacteria
- Fungi
- Protozoa
- Algae
- Viruses
4
Q
- aka microbiota
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MICROBIOME
5
Q
- microbes that live stably in and on the human body
A
MICROBIOME
6
Q
types of microbiota
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- normal microbiota– indefinitely colonize the body
- transient microbiota– transiently colonize the body
7
Q
Parts of a Prokaryotic Cell
A
- Glycocalyx
- Cell Appendages
-* Flagella
-* Axial filaments
-* Fimbriae
-* Pili - Cell Wall
- Plasma Membrane
- Cytoplasm
- Ribosomes
- Inclusions
- Nucleoid
- Endospores
8
Q
- “sugar coat”
- a viscous (sticky), gelatinous polymer that is external to the cell wall
A
Glycocalyx
9
Q
- composed of polysaccharide, polypeptide, or both
- made inside the cell and secreted to the cell surface
- 2types
- Capsule
- Slime layer
A
Glycocalyx
10
Q
- contributes to bacterial virulence
- protects pathogenic bacteria from phagocytosis
A
Capsule
11
Q
- long filamentous appendages that propel bacteria
A
Flagella
12
Q
– movement of bacterium toward or away from a particular stimulus
* Chemotaxis
* Phototaxis
A
Taxis
13
Q
- aka endoflagella
A
Axial Filaments
14
Q
- bundles of fibrils that spiral around the cell
- structure for motility in spirochetes
A
Axial Filaments
15
Q
- arise and anchored at the ends of the cell beneath an outer sheath
- similar structure to flagella
A
Axial Filaments
16
Q
- hairlike appendages that are shorter, straighter, and thinner than flagella
- consist of a protein called pilin arranged helically around a central core
- present in manyg(-)bacteria
A
Fimbriae and Pili
17
Q
- a few to several hundred per cell
- adhere to surfaces
A
Fimbriae
18
Q
- longer and fewer than fimbriae (1-2/cell)
- for motility and DNA transfer (e.g. sex pili in conjugation)
A
Pili
19
Q
- complex, semirigid structure
Functions:
* prevents bacterial cell rupture
* maintain shape of bacterium
* point of anchorage for flagella
A
Cell Wall
20
Q
- present in all bacteria, except Mycoplasma and Ureaplasma
A
Cell Wall
21
Q
- contributes to the ability to cause disease
- the site of action of some antibiotics
- differentiates major types of bacteria based on composition
A
Cell Wall
22
Q
- composed of peptidoglycan (aka
murein) alone or in combination with
other substances - repeating disaccharide: acetylglucosamine
(NAG) acetylmuramicacid(NAM) - polypeptides
A
Cell Wall
23
Q
- many layers of peptidoglycan, forming a thick, rigid structure
A
Gram-Positive Cell Wall
24
Q
- one or very few layers of peptidoglycan and an outer membrane
A
Gram-Positive Cell Wall
25
Contains lipopolysaccharide (LPS) and Periplasmic Space
Gram-Positive Cell Wall
26
lipids and carbohydrates
lipopolysaccharide (LPS)
27
– released when g(-) bacteria die; causes fever,
shock, blood clotting, dilation of blood vessels)
Lipid A (Endotoxin)
28
structural function
Core polysaccharide
29
functions as antigen
- *also present in Listeria monocytogenes (a gram-positive bacteria) but does
not function as endotoxin
O polysaccharide
30
between inner membrane and outer
membrane
Periplasmic Space
31
* present in Mycobacterium and Nocardia
* contains high concentrations (60%) of a hydrophobic waxy lipid
(mycolic acid)
* e.g., in Mycobacterium and Nocardia
Acid-Fast Cell Wall
32
* inside the cell wall and encloses the cytoplasm
* consists mainly of phospholipids, proteins, glycoproteins, glycolipids
* lacks sterols, except Mycoplasma and Ureaplasma
Plasma Membrane
33
* Structure: Fluid Mosaic Model
-* Lipid Bilayer
-* Membrane Proteins
* Function: selective barrier
Plasma Membrane
34
* the substance of the cell inside the plasma membrane
* ≈80% H2O and contains primarily proteins (enzymes), carbohydrates, lipids, ions, and many LMW compounds
* contains the cytoskeleton, nucleoid, ribosomes, and cytoplasmic inclusions
Cytoplasm
35
* site of protein synthesis
* gives the cell a granular appearance
* consists of protein and rRNA
* 2subunits (70s):
* Large(50s)
* Small(30s)
Ribosomes
36
Inclusions
* Metachromic granules –inorganic phosphate (polyphosphate) that can be used in the synthesis of ATP
* Polysaccharide granules – glycogen and starch
* Lipid inclusions – lipid
* Sulfur granules – sulfur and S-containing compounds
* Carboxysomes–ribulose 1,5-bisphosphate carboxylase
* Gas vacuoles – hollow cavities
* Magnetosomes–ferric oxide
37
* nonuclear envelope
* contains asingle long, continuous, and circularly double-stranded
DNAcalledthebacterial chromosome
- * nohistones
- * attached totheplasmamembrane
Nucleoid
38
* extrachromosomal DNA
* small usually circular, double-stranded DNA
* replicate independently from chromosome
* notcrucial for survival but adds some advantages
Plasmid
39
* specialized“resting”cells
* highly durable dehydrated cells with thick walls and additional layers
* can survive extreme heat, lack of water, and exposure to many toxic chemicals and radiation
* resistant to processes that kill vegetative cells (e.g. desiccation, chemicals, radiation, heating)
Endospores
40
* formedinternal to the cell membrane
* contains high amounts of dipicolinic acid (DPA), and calcium
ions
* present in Clostridium and Bacillus
Endospores
41
* Sporulation/Sporogenesis– spore formation
* Germination–return of endospore to vegetative state
Endospores
42
The Three Domains of Life
Bacteria
Archeaa
Eukarya
43
Five Kingdoms
Fungi
Plants
Animals
Protista
Monera
44
Prokaryotes 2 types
Bacteria
Archaeabacteria
45
– unicellular prokaryotes; have peptidoglycan cell walls; reproduce by binary fission
Bacteria
46
- live in extreme environments and carry
out unusual metabolic processes; no peptidoglycan in cell walls
* Methanogens– obligate anaerobes that produce CH4 from CO2 and H2
* Extremehalophiles– requiremhigh concentrations of salt for survival
* Hyperthermophiles–grow in extremely hot nenvironments
Archaeabacteria
47
3 types of Eukaryotes
Fungi, Protists, Animal Parasites
48
– may be unicellular (yeasts) or multicellular (moldsand mushrooms; form hyphae); have chitin cell walls; reproduce sexually (meiosis) or asexually (spores)
Fungi
49
– eukaryotes that are not plants, fungi, or animals
* Protozoa– unicellular nonphotosynthetic protists; reproduce sexually or asexually
* Algae– unicellular photosynthetic protists; have cellulose cell walls; reproduce sexually and asexually
Protists
50
–multicellular eukaryotes
* Flatworms
* Roundworms
Animal Parasites
51
* acellular obligatory intracellular parasites
* Structure:
* single type of nucleic acid, either DNA or RNA
* protein coat (sometimes enclosed by an envelope) that surrounds
the nucleic acid
* multiply inside living cells by using the synthesizing machinery of
the cell
Viruses
52
* infectious proteinaceous particle
Prions
