Module 1 : Basic Characteristics of Microorganisms Flashcards
What are the two general characteristics of an Endospore?
1) Highly resistant, dehydrated form, resistant to environmental effects
2) Metabolically dormant- One spore germinates to form one vegetative cell
What composes an Endospore?
Concentrated, dehydrated, densely packed nucleic acids and metabolic proteins within a thick spore coat
What is an Endospores function?
survivability in extreme environments, maintain viability for years
Define a Capsule’s composition and function
Composition: Polysaccharides
Function:
- Resistant to Phagocytosis
- “Hides” surface antigens
- Assists in attachment
What is material composes a bacterial flagellum?
Proteins
What is the function of the bacterial flagellum?
Motility- propelling/locomotion
Chemotaxis/Phototaxis
How do spirochetes move?
By the means of axial filaments through the “spring” resulting in a corkscrew motion
What is the compositon of a bacterial fimbriae?
Short, thin, threadlike glycoprotein strands protruding from the cell
Define Saprophyte
An organism which utilizes non-living organic matter
Define Parasite
an organism which lives in or on a host organism
Define Fastidious
Organism that have specific requirements for nutrients which they cannot synthesize
Define nutrients in the context of growing bacteria
growth supporting substance (ie. Food Substance)
Define Bacterial Cultivation
Growth of particular microorganisms/under controlled conditions
Explain Aerobic Oxygen utilization
Bacteria require atmospheric oxygen (21%)
Define Microaerophilic
Bacteria that requires reduced oxygen concentration (5-10%)
Define Anaerobic
Bacteria that require an absence of oxygen
Define Facltative
Can grow with or without oxygen
Explain 4 Optimal Environmental Needs of Bacteria
Temp: 35 C
pH: 6.8-7.4
Humidity: 60-80%
CO2: some require 5-7%
Define Culture Media
The material in/on which bacteria grow in the laboratory
How long does it take for one cell to divide into two?
30-60 Min for most
15-30 Hrs for some
How long does it typically take to grow a colony of bacteria?
15-48hrs for most
How do we define a colony of bacteria?
1-3mm diameter
Smooth, Shiny, Butter
What are the 3 Cell Characteristics of “Atypical” Bacteria?
1) Some Obligate, Intracellular parasites
2) Modified cell wall structures
3) Complicated or modified reproductive method
What type of cell is a Fungi?
Eucaryotic
What are the two main Fungi Cell Morphology and Structure?
Yeast and Mould
Explain the 5 Characteristics of Yeast
1) Single Cell
2) Oval or Spherical
3) Reproduce by Budding
4) 4-15um diameter
5) Smooth, Shiny
Define Hyphae
Multicellular long filamentous cells that branch and intertwine
How does Mould reproduce?
Reproductive Hypae: Produce spores
How long does it take to grow a Yeast colony?
2-5 Days
How long does it take to grow a Mould colony?
5-21 Days
Name the 5 Classifications of Microorganisms and their cell type
1) Parasitic Worms - Eucaryotic
2) Protozoa/Algae- Eucaryotic
3) Fungi- Eucaryotic
4) Bacteria- Procaryotic
5) Viruses-
What is a Procaryotic cell type?
Single cell organisms without a formed nucleus or organelles
What is the typical size of the typical bacteria?
0.5-0.8um in diameter
1-6um in length/ most 1-2um
What is cell morphology?
External appearance of the cell, colony, other item
Coccus
Spherical shape
Bacillus
Rod/Cylindrical
Define Pleomorphic
Can have various distinct forms
Coryneform
Club Shaped
Spirochete/Spirilum Shape
spiral or corkscrew
Explain the 2 Composition Characteristics of the Cytoplasmic Membrane
1) Phospholipid Bilayer- hydrophilic heads/hydrophobic tails which affect movement accross the membrane
2) Proteins- Porins create channels and other create enzymes
What are the four functions of the cytoplasmic membrane
1) Selective Permeability
2) Energy Production
3) Synthesis/Transportation of Peptidoglycogen/Teichoic acids/outer membrane components
4) Secretion of Extracellular hydrolitic enzymes
Explain the 3 Cell Wall Functions
1) Provide Shape/Rigidity
2) Protection from Env./microbial agnts
3) Attachment site (Antibodies/Antigens)
What are three parts of a Gram-Positive Cell Wall?
1) Peptidoglycogen (60-80%)
2) Alternating NAG-NAM with peptide connections
3) Teichoic Acids
What three molecules compose the “outer membrane” of the Gram-negative cell wall?
Lipoproteins, Lipopolysaccharides, phospholipids
What are 3 components of the Gram-Negative Cell Wall?
1) Peptidoglycogen (10-20%)
2) Lipoprotein Layer creates a Periplasmic Space
3) Has an Outer membrane whihc hosts the “O” Antigen and Lipid A endotoxin molecule
Describe the 3 main descriptors of viruses
1) Obligate, intracellular
- Takes contol of host cell
- Requires metabolic process of living cell to replicate
2) Contains either DNA/RNA
3) Unaffected by Antibiotics
What is the typical virus size?
18 to 300nm
What is a viron?
Fully Developed virus particle
What is contained in a virus core?
Nucleuic Acid (DNA/RNA)
Describe the two structures of the capsid
Helical: Molecules are closely aligned to helical shape of nucleuic acid
Icosahederal- Similar to soccer ball, pentagalon sides
Purpose and Compositon of Capsid
1) Contain/Protect Nucleic acid
2) Proteins serve as antigens to attachment site
(Protein)
What are two Components of a Envelope?
Lipid Bilayer (from host cell or nuclear membrane
Glycoproteins: site for attachment/antigen
What are 3 functions of a Envelope?
Bilayer provides protection from environment/Site of attachement to host cell/Proteins serve as antigens during infection and antibody attachment
What makes up the “head’ of the virus?
Core, Capsid
What are the three components of the tail?
Sheath, Tail Fibers, Base with Enzymatic pins
Describe the composition and purpose of the tail fibers
Mainly protein with Polysaccharide Tips (Carbohydrate) which help attachment to host
Describe the Sheath
Column of protein connecting head to base/Re configures into a tube once attached
What does the mRNA go to when injected into the host to begin its replication or lytic cycle?
Ribosomes
For Laboratory cultivation how long does it take to isolate and identify a virus
2 days to 4 weeks depending on the virus
What kind of cell type is a protozoa?
Eucaryotic
Are protazoa a single celled organism with intacellular organelles?
Yes
How are Protozoa types identified?
Their specific locomotion
Amoebae
Moves by Pseudopodia (false foot)
Flagellates
Move by flagella
Ciliates
Move by Cilia
Apicomplexans
(Sporazoans) non-motile in their mature forms
General size of protozoa?
2um to 1mm
What are the two basick morphological stages of protozoa?
Trophozoite
Cystic Stage
Explain the Trophozoite Stage
1) Active, vegetative, motile, feeding stage
2) Responsible for most pathological conditions in host
Explain the Cystic Stage
1) Dormant, nonmotile, non-feeding
2) Cyst wall, resilient to environment
What are the characteritics of Helminths?
Eucaryotic, Multicellular simple body systems
Describe the 4 characteritics of Trematodes (Fluke)
1) 1 Body, leaf like
2) Size: 500um to 60mm
3) Partial Alimentary Tract
4) Monoecious
Describe the 4 characteristics of Cestodes (Tapeworms)
1) Segmented body parts
2) 2mm-12 meters
3) No Alimentary Tract
4) Monoecious
Describe Aschelminthes
1) Cylindrical- wrinkled
2) 300um to 1 meter
3) Complete alimentary tract
4) Dioecious
