Microbiology flashcards set 1

Microbiology 111 with Stevenson at Miami University of Ohio

About this deck

By: Mike Bartol
Textbook:

Microbiology: A Systems Approach
Created: 2011-01-11
Size: 32 flashcards
Views: 30

About StudyBlue

STUDYBLUE makes things that make you better at school. Things like online flashcards with photos and audio. Things like personalized quizzes and friendly reminders about when (and what) to study next. Think of it as a digital backpack™: access to all of your study materials online and on your phone. STUDYBLUE exists to make studying efficient and effective for every student, for free. Join us.

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis

Sign up (free) to study this.

Host

organism which provides nutrients, etc. to another organism

Parasite

organism which lives at the expense of (and may even harm) its host; the parasite is generally smaller than the host and is metabolically dependent upon it

Disease

an upset in the homeostasis of the host, resulting in generation of observable changes

sign - objective evidence of damage to the host (fever, rash, vomiting)
symptom - subjective evidence of damage to the host (headache, anorexia)

Infectious disease

one in which detrimental changes in health of the host occur as a result of damage caused by a parasite

Pathogen

microorganism that is capable of causing disease

Virulence

a measure of pathogenicity, which is the ability to cause disease

Virulent

microorganisms that readily cause disease (only small numbers of the microorganism are required to initiate and sustain infection)

Attenuated

microorganisms with reduced ability to cause disease

Avirulent

microorganisms that do not cause disease

Opportunistic

microorganisms that may or may not cause disease generally colonize, but do not infect, the host when usually found associated with a host, called normal microbiota can cause disease if they are inadvertently introduced into a site where they do not usually reside, especially inside host tissues

To cause disease, a pathogen must:

Contact the host - be transmissible
Colonize the host - adhere to and grow or multiply on host surfaces
Infect the host - proliferate in host cells or tissues
Evade the host defense system - by avoiding contact that will damage it
Damage host tissues - by physical (mechanical) or chemical means

Virulence Factors

Adhesins - enable parasites to attach to host cells or tissues
Invasins - enable parasites to enter and/or move through host cells or tissues
Evasins - enable parasites to escape from host defenses
Toxins - enable parasites to damage host cells

prokaryotes

small, "simple" cells that typically have a cell wall and cytoplasmic membrane surrounding their cytoplasm, which contains ribosomes and a nucleoid comprised of one or more chromosomes with DNA genes, but have no membrane surrounding their nucleoid

eukaryotes

large, "complex" cells with a nucleus that contains multiple chromosomes (with DNA genes) surrounded by a membrane plus a cytoplasm containing ribosomes and membrane-bound organelles, such as mitochondria, endoplasmic reticulum, vacuoles, chloroplasts (plants only), Golgi bodies

viruses

acellular (not cells) nonliving entities, made up of genetic material (DNA or RNA) enclosed in a protein coat (many also have a membrane called an envelope), which can reproduce themselves only by infecting cells and utilizing cellular materials and processes

morphology

these prokaryotes are typically ~0.2-2 x 1-5 um and may becylindrical (bacilli), spherical (cocci), helical (spirilla or spirochetes) or polymorphic (many shaped or amorphous)

cell wall

rigid structure (peptidoglycan +/- lipopolysaccharide) that protects against osmotic pressure damage and provides cell shape - cylindrical (bacillus); spherical (coccus); helical (spirillum)

cytoplasmic membrane

this lipid/protein outer boundary of the cytoplasm regulates what goes in and out of the cell (permeability)

ribosomes

small RNA/protein particles required for protein synthesis

chromosome

large single strand of DNA that contains the "blueprint" for all cell structure and activity in regions called genes

plasmids

DNA that contains only a few genes and is exchanged between bacteria (codes for antibiotic resistance or virulence factors)

inclusions

intracytoplasmic storage bodies (may contain phosphates, iron, lipids, etc.)

capsule

polysaccharide "coatings" secreted by cells (adhesins)

flagella

long, thin protein (flagellin) polymers that provide motility

pili

long, thin protein (pilin) polymers that act as adhesins

endospore

thick-walled protective structures; highly resistant to adverse environmental conditions (high temperature, drying, O2, etc.)

growth

process of cell enlargement and proliferation (increase in number)

proliferate by binary fission

division of a cell into two cells of equalsize and composition

growth curve - phases:

lag - cells get ready to synthesize components needed for growth
log - rapid proliferation (exponential or logarithmetic); generation time (gt) is the time required for the number of cells to double
stationary - cell proliferation is balanced by cell death caused by nutrient depletion or accumulation of metabolic by-products
death - rapid (logarithmic) cell death occurs

nutritional requirements 1

chemical - they derive their energy and nutrition from organic compounds that they digest extracellularly using enzymes they secrete

water - living biological entities are typically ~70% water
essential elements - C (carbon), H (hydrogen), O (oxygen), N (nitrogen), P (phosphorus), S (sulfur)
trace elements - Ca (calcium), Mg (magnesium), Fe (iron), Na (sodium), K (potassium), Zn (zinc), Co (cobalt), Mn (manganese), plus others
organic growth factors - vitamins and other essential organic nutrients

nutritional requirements 2

physical

temperature - pathogenic bacteria grow best between 20C and 40C (human body temperature is 37C)
oxygen - aerobes, facultative aerobes, microaerophiles, anaerobes
pH - most pathogenic bacteria "prefer" near-neutral conditions (pH ~6-8), but some can thrive in acid (pH down to 3) or alkali (pH up to 10)
salts - no special requirements; pathogenic bacteria grow well at salt concentrations found in the human body

importance and habitat of cell growth

most bacteria are saprophytic (decomposers), but some are pathogenic; as a group, they are found everywhere

About this deck

By: Mike Bartol
Textbook:

Microbiology: A Systems Approach
Created: 2011-01-11
Size: 32 flashcards
Views: 30

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis