TEST 1 Flashcards
Microbiology
Study of small microorganisms which cannot be seen with the unaided eye
Species
a group of organisms that can reproduce naturally with one another and create fertile offspring.
Aseptic technique
a set of procedures that prevents unwanted contamination of surfaces and materials by microbes
Parasitology
branch of biology concerned with parasites and protozoa
Epidemiology
Study of the spread of disease
Bacteriology
Study of bacteria
Immunology
Study of immunity
Recombinant DNA technology
The field of genetic engineering
Using labs and enzymes to manipulate and isolate DNA segments to create new genes/functions
Mycology
Study of fungus
Virology
Study of viruses
Infectious disease
Diseases caused by microbes
*known pathogens
Normal microbiota (flora)
bacteria that are a normal part of human body
*harmless and beneficial
Pathogens
microorganism that can cause disease
Biogenesis
The hypothesis that living matter only comes from living matter
Genus
Related living things, made up of 1 or more species
The category that is above species
capitalized latin name
Spontaneous generation
the hypothetical process by which living organisms develop from nonliving matter
What is the proper nomenclature for microbes?
Genus and Species
both italicized and Genus is always capitalized
*exception is viruses
*often refer to shape or environment
BACTERIA
Type of cell?
Classified by? Shapes
Survive by?
Reproduction method?
Other?
TYPE: Prokaryotic - Unicellular
CLASSIFIED BY: Bacillis or rods
Coccus
Spirillum or spiral
*Peptidoglycan - a protein complex
SURVIVE BY: Metabolize organic chemicals from breaking down materials living or not - recycle. *some make their own nutrients
REPRODUCE: Binary fission - asexual
OTHER: Motile - flagella, pili, fimbriae
ARCHEA
Type of cell?
Classified by? Shapes
Other?
TYPE: Prokaryotic - no cell wall, no peptidoglycan
CLASSIFIED: Methanogens - methane
Halophiles - Salt
Thermophiles - heat
OTHER: not known to be pathogens
FUNGI
Type of cell?
Classified by? Shapes
Reproduction method?
Other?
TYPE: Eukaryotic - uni or multicellular
CLASSIFIED: Large = Molds & mushrooms
Small = yeasts
REPRODUCE: sexually and asexually
OTHER: natural decomposers, obtain nourishment from their surroundings
No photosynthesis
Spores - ways to move
PROTOZOA
Type of cell?
Reproduction method?
Other?
TYPE: Eukaryotic, unicellular & motile
REPRODUCTION: Sexual or Asexual
OTHER: Move through pseudopods, cilia, flagella, wide variety of shapes
*some disease causing
Algae
Type of cell?
Survive by?
Other?
TYPE: Photosynthetic eukaryotic, uni or multicellular
Salt and fresh water
SURVIVE: Photosynthesis
OTHER: produce oxygen and essential carbs for other organisms
MULTICELLULAR ANIMAL PARASITES
2 helminths:
not technically microorganisms, but important for medical
HELMINTHS: Round worms & ringworms
VIRUSES
Type of cell?
Classified by? Shapes
Survive by?
Acellular
CLASSIFICATION:
Capsid- DNA or RNA surrounded by protein coat
Enveloped- capsid encased in lipid membrane
*technically not living, depend on hosts cell to reproduce
PASTEUR
When?
What?
PASTEUR
1861 - proof of microbes in the air and introduces biogenesis
*Sterile media in a closed environment failed to produce life
Heat can kill microbes - forms aseptic technique
Developed pasteurization = lower heat longer periods = increased shelf life
JENNER
When?
What?
JENNER
1798: Creates smallpox vaccine
*infection from cowpox prevents smallpox
SNOW
When?
What?
SNOW
1854 - mapped cases of cholera to water and stopped epidemic
LISTER
When?
What?
LISTER
Professor in Scotland, amputations
Phenol - kills microbes, infections decrease
KOCH
When?
What?
KOCH
Showed disease caused by microbe
1876: Koch’s postulates
- Same organism present 100% of time
- Isolate & make sure its the only organism
- Infect healthy animal
- Observe same symptoms
- Must see only same organism
= CAUSE
FLEMING
When?
What?
FLEMING
1928: Discovers antimicrobial agents
*accidentally discovers mold can inhibit bacterial growth -penicillin
WATSON, CRICK, WILKINS, FRANKLIN
When?
What?
WATSON, CRICK, WILKINS, FRANKLIN
1953 - determined structure for DNA
*franklin actually did expiermnent
Problems facing modern microbiologists
Emerging and reemerging diseases - the fast pace of travel/movement
Increasing antimicrobial resistance - overprescribed antibiotics
Climate change - change habitats and species move to new regions
Humans - intentional weaponizing of biological agents
Capsule?
Slime layer?
Thick tightly bound glycocalyx on prokaryotes
The thin loosely bound glycocalyx on prokaryotes
Flagellar arrangements
Monotrichous -
Peritrichous -
Lophotrichous -
Amphitrichous -
Atrichous -
Monotrichous - 1 filament, polar
Peritrichous - Filaments all around cell
Lophotrichous - 2 or more filaments on same side
Amphitrichous - Multiple filaments at each end
Atrichous - no flagella present
Phototaxis?
Taxis?
Chemotaxis?
Phototaxis - movement based on light
Taxis - movement towards or away from stimulus
Chemotaxis - movement based on chemicals
Passive transport
3 types?
Active transport
1?
PASSIVE TRANSPORT- move by concentration gradient
- *Osmosis** - water
- *Diffusion** - non-water molecules
- *Faciliated diffusion** - uses transporters (permeates)
ACTIVE TRANSPORT - required energy
Group translocation- substance is modified as it crossed over the membrane so new substance is impermeable
Osmotic pressure?
Isotonic?
Hypotonic?
Hypertonic?
Osmotic pressure - pressure needed to stop the flow of water across a membrane
Isotonic- concentration same inside and outside of the cell
Hypotonic - concentration of solutes lower outside of cell
Hypertonic - concentration of solutes higher outside of cell
Prokaryotes
Plasmid -
Ribosome -
Endospores -
Sporulation -
Germination -
Prokaryotes
Plasmid - carry genes for antibiotic resistance, toxin tolerance and enzyme production. Can be transferred from one bacteria to another
Ribosome - Protein synthesis
*Prokaryotes have 50S+ 30S = 70S
Eukaryotes have 60S + 40S = 80S
Endospores - resting structures formed by bacteria when living in an inhospitable environment.
Sporulation - the process of making a spore
Germination - process of returning a endospore back to vegetative state
Peptidoglycan?
Mordant?
Peptidoglycan - bacterial cell wall - carbohydrate backbone composed of alternating NAM and NAG. Interlaced with peptide cross-bridges
Mordant - a substance, typically an inorganic oxide, that combines with a dye or stain and thereby fixes it in a material.
List the common shapes and arrangements of bacterial cells
Bacillus - single rods
Diplobacilli - joined at ends
Streptobacilli - chain
Coccobacilli - oval shape, single bacilli
Coccus - Sphere
Single cocci - single sphere
Diplococci - pairs
Streptococci - chain like
Tetrads - groups of 4, square
Sarcinae - groups of 8, cube
Staphylococcus - grape like clusters
Spiral - twist
Vibrios - single, curve or bent
Spirilla - corkscrew. Rigid
Spirochetes - helical, flexible
Structure and function of Prokaryotic
Glycocalyx -
Flagella -
Axial filaments -
Pili/fimbria -
Glycocalyx - sticky polysaccharides and protein. Protection from the environment and macrophages adherence may provide nutrients
Flagella - long filamentous appendages. Motility - rotate like a propeller. Hook, filament and basal body
Axial filaments - unique to spiral bacteria. Cause bacteria to rotate resulting in motion
Pili/fimbria - short thin appendages, mostly on gram - and some +. adhesion to surfaces, motility and sex. Cell to cell conjugation - method of transferring DNA
Composition of bacterial cell wall
& Function
Composed of a polymer called peptidoglycan
*carbohydrate backbone composed of alternating NAM (N-Acetylmuramic acid) and NAG (N-acetyl glucosamine) . NAMS contains 4 amino acid side chains
The backbone is interlaced with peptide cross-bridges between the peptide side chains
FUNCTION - maintain shape, protection from physical and osmotic lysis
Difference between Gram-positive and Gram-negative cell walls
Gram + cell walls are THICK w/ multiple layers of peptidoglycan
*also contain teichoic acids = regulate the movement of cations & excessive cell wall breakdown
Gram - cell walls are THIN sometimes only 1 layer of peptidoglycan
*have outer layer = lipopolysaccharide - Sugar as antigen and Lipid A as endotoxin shock
Also contains pores to allow molecules to mvoe
What is the process of gram staining?
- first heat fix bacteria to glass micro slides
- apply primary stain - crystal violet for 1 min
- Rinse - all cells purple
- Add grams of iodine for 1 min
*iodine causes CV to crystalize in cells becoming trapped - Rinse excess iodine away
- Decolorize cells with acetone alcohol
* this will attempt to pull CV out of cells
*Thin wall will present in gram - cells and allow dye to flow out/ gram + will keep it in - Apply a counterstain, safranin for 1 min
Gram + will appear purple
Gram - will appear pink
Identify the function and location of
Lipopolysaccharide -
O antigen -
Lipid A -
Lipoteichoic acid
Lipopolysaccharide - gram negative -outer membrane & contains
O antigen - Sugar acts as antigens
Lipid A - endotoxin - causes endotoxic shock
Lipoteichoic acid - gram positive cell wall & function as regulation of movement of cation & protection from cell wall breakdown
What are 2 bacteria with atypical cell walls and why
Mycoplasma - lack cell walls, sterols in their membranes protect from lysis
Mycobacterium - thick cell walls that contain mycolic acid causing them to be waxy. unable to stain
Prokaryotes - structure and function
Plasma membrane -
Cytoplasm -
DNA -
Ribosomes -
Plasma membrane - encloses cytoplasm/ selectively permeable
Cytoplasm - Fluid component of the cell. mostly water
DNA - aggregates in nucleoid or nuclear area (not surrounded by membrane) CIRCULAR & attached to plasma membrane
Ribosomes - Protein synthesis - 70S
Eukaryotes
Flagella
Cilia
Microtubule
Flagella - beat in a wave pattern - large 200nm, long & few in number
Cilia - short hair like, high in number
Microtubule - makes up cilia and flagella in a 9+2 format
* long hollow tubes of protein called tubulin / flexible skeleton
Eukaryotes
Endocytosis -
Phagocytosis -
Pinocytosis -
Receptor-mediated endocytosis -
Endocytosis - how cells engulf larger particles
Phagocytosis - pseudopods surround particles and engulf
Pinocytosis - aka cellular drinking, cell folds in, creating a divot and folds around the area
Receptor-mediated endocytosis - virus binds to receptor initiating similar to pinocytosis
Eukaryotes
Chromatin -
Organelle -
Histones -
Nucleoli -
Chromatin - a thread-like mass of protein and DNA when not replicating
Organelle - membrane-bound structures
Histones - proteins that keep DNA bound and function to regulate transcription
Nucleoli - within nucleus, 1 or more spherical bodies, sites of rRNA synthesis
Eukaryotes
Cristae -
Matrix -
Nuclear pores -
Grana -
Thylakoids -
Cristae - folds in inner membrane of mitochondria
Matrix - fluid-filled space in inner membrane of mitochondria
Nuclear pores - allows access to nuclous / DNA
Grana - stack of thylakoids
Thylakoids - membrane sacs in chloroplasts where chlorophyll
Endosymbiotic theory
Evidence?
Prokaryotic developed first
-develops a primitive nuclear membrane to protect DNA
- Big bacteria engulfed small bacteria
- Small bacteria lost their DNA. relied on large bacteria
- Reproduced with small in large bacteria
- 2 eventually became indistinguishable
Evidence - mitochondria & chloroplasts same shape and size as bacteria, circular DNA, reproduce independently of host cell, ribosomes 70S
Major differences between Prokaryotic and Eukaryotic cells
Size
Nuclear membrane?
Organelles
Flagella
Glycocalyx
Cell wall
Plasma membrane
Prokaryotic VS Eukaryotic
0.2-2 um - 10-100um
No nuclear membrane - true nucleus
No or few organelles - organelles
Flagella - 2 protein - complex
Glycocalyx capsule - present in some that lack a cell wall
Cell wall - complex - simple
Plasma membrane - carb & lacks sterols - sterols& carbs
Major differences between Prokaryotic and Eukaryotic cells
Cytoplasm
Ribosomes
DNA
Cell division
Sexual recombination
P vS E
Cytoskeleton - Cytoskleton (microfilaments, tubules)
Small - larger
circular, lack histone - linear, histone
binary fission - mitosis
non, transfer DNA only – meiosis
Obligatory intracellular parasite
Require living host to multiply
How are viruses defined?
(4)
Contain a single type of nucleic acid, DNA or RNA
Contain protein coat that surrounds nucleic acid
Multiples inside living cells by using the cells’ machinery
causes specialized structures that can transfer the viral nucleic acid to other cells
Capsid
Viral envelope
the protein shell of a virus particle surrounding its nucleic acid.
Capsid is surrounded by a lipid bilayer that contains proteins. Usually derived from host cells membranes - contains spike protiens
Bacteriophage
a virus that infects and replicates within bacteria and archaea
Host range
Tissue tropism
Host range - the range of cell types and host species a virus is able to infect.
Tissue tropism - the ability of a given virus to productively infect a particular cell
Lytic -
Lysogenic -
Plaque -
Lytic - occurs when a virus has infected a cell, replicated new virus particles, and bursts through the cell membrane.
Lysogenic - a virus that specifically infects a bacterium, achieves the manufacture of copies of its (DNA ) genetic material by integrating the viral DNA into the DNA of the host bacteria.
Plaque - a clear area on an otherwise opaque field of bacteria that indicates the inhibition or dissolution of the bacterial cells by some agent, either a virus or an antibiotic.
Bacteriophage therapy
deliberate application of phages to kill bacteria in infected tissue
*target bacteria cells and leave host cells alone
*drawback - phages are foreign and will be cleared from the immune system in 7-10 days
Restriction enzyme
a protein produced by bacteria that cleaves DNA at specific sites along the molecule.
In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.
Cytopathic effects
Cancer
Oncogene
Oncogenic virus
Cytopathic effects - structural changes in a host cell resulting from viral infection. *diagnostic tool
Cancer - Unregulated cell division
Oncogene - A gene that is a mutated (changed) form of a gene involved in normal cell growth
Oncogenic virus - viruses that cause or give rise to tumors
Acute infection
Latent infection
Persistent infection
Acute infection - simplest/most common - triggers immune
Latent infection - remains in host for long periods
Persistent infection - disease progresses, immune systems fails
The basic structure and common morphologies of viruses
(4 morphologies)
Structure - Nucleic acid, Capsid, envelope
Morphologies -
Helical -
Polyhedral - many-sided (20 faces, 12 corners)
Enveloped - Capsid covered by envelope, spherical
Complex - complicated structures. IE Bacteriophage
Explain formal viral taxonomy
Virus family end in ?
Virus genus end in?
Grouping based on the nucleic acid sequence as well as structure
Grouped into Family and genus
Virus family end in - Viridae
Virus genus end in - Virus
Host range & tissue tropism
Compare and contrast
Host range - which organisms a virus can infect - limited in number. Mediated by attachment proteins
Tissue tropism - availability of virus receptors
Explain the plaque method of cultivating bacteriophages
Mix bacteriophages with host bacteria and nutrient agar
*bacteria in the area of the virus are destroyed
*Area of lysis is called plaque
Steps in Lytic
Steps in lysogenic bacteriophage infections
(5)
(5)
- *Lytic** -
1. Attachement/absoprtion
2. Penetration
3. Biosynthesis
4. Maturation/assembly
5. Release = cell death
Lysogenic -
1. Attachment
2. Penetration
3. Phage DNA integrates with bacterial chromosomes by recombination
4. Produces normally
5. Occasionally lytic if environment is bad
5.
Methods in the cultivation of animal viruses
(3)
Whole animals
Cultivated in embryonated eggs
Cultured in cell culture in the lab
Techniques used to identify viruses
(2)
RFLP - small differences in a genome are detected to ID an organism
PCR - a small region of nucleic acid is replicated, found only in virus and look to see if it matches the person
Mycology
Thallus -
Hyphae -
Septate hyphae -
Coenocytic hyphae -
Mycology - the scientific study of fungi.
Thallus - major stock or body of molds
Hyphae - long thin filaments that make the thallus
Septate hyphae - Contain crosslinked walls
Coenocytic hyphae - one continuous cell with multiple nuclei
Vegetative hypha -
Aerial hypha -
Mycelium -
Dimorphism -
Vegetative hypha - responsible for nutrient absorption
Aerial hypha - responsible for reproduction *contain spore
Mycelium - the vegetative part of a fungus, consisting of a network of fine white filaments (hyphae).
Dimorphism - can grow as either yeast or molds
Conidosphore
*Conidiophore
Sporangiospore
*Sporangiophore
Conidosphore - Asexual = not enclosed by a sac
*form at the end of a stalk-like structure called = Conidiophore
Sporangiospore - enclosed by a sac
*located at end of aerial hyphae called Sporangiophore
Mycosis
Dermtophytes
Keratinase
Mycosis - fungal disease
Dermtophytes - fungi that affect epidermis
Keratinase - produced by dermatophytes - degrades keratin
Define mycology and its importance to medicine and agriculture
Mycology - study of fungi
Importance to medicine - increasing nosocomial infections & problematic for immunocompromised
Importance to agriculture - all plants rely on mycorrhizal for nutrients & devasting pathogens to commercial crops
How do fungi differ from bacteria?
Fungi are:
Eukaryotic. have sterols in membrane
Lack peptidoglycan
Heterotrophic
Sexual and asexual
Difference between budding and fission yeast
Budding - bud forms on the surface of the cell. Can produce up to 24 daughter cells
Fission - cell elongates, nucleus/organelles replicate, cell pinched off in middle and 2 daughter cells are produced
What temps are dimorphic fungi changing?
37 = yeast like
25 = mold like
Regulation is also depending on Co2
Differences between fungal and bacterial spores
Fungal spores
Reproductive
Undergo sexual recombination
Do not provide protections
How are sexual spores formed?
Plasmogamy
Karyogamy -
Meiosis -
The result from sexual reproduction, 3 phases
Plasmogamy - Donor cell penetrates recieptent cell
Karyogamy - both nucleus fuse = diploid zygote
Meiosis - diploid give rise to haploid
