Exam 1 Principle 1-1 (Grace's Version) Flashcards
What microorganisms make up the microbiome of the human body?
bacteria, viruses, fungi, protozoa
What microorganism does not contribute to the human microbiome?
helminths (worms)
What are parasitic organisms?
symbionts that harm or live at the expense of their host
What are commensal organisms?
also known as normal microbiota
-microbes frequently found on or within the bodies or healthy persons
What is an infection?
growth and multiplication of parasite on or within a host
What is an infectious disease?
disease resulting from infection
Do infectious diseases always come from outside the body?
no. they can be caused by exogenous sources, but can also be caused my microorganisms present in the body normally, but moving to a different area of the body or during states of lowered immunity
What is a pathogen?
any parasitic organism that causes infectious disease
What is primary (frank) pathogen?
pathogen that causes disease by direct interaction with host
-will cause disease in host regardless of immune status or presence of other microorganisms
What are opportunistic pathogens?
pathogens that cause disease only under certain circumstances
-oral candidiasis is an example
What is pathogenicity?
ability of parasite to cause disease
What is virulence factor?
any component of a pathogenic microbe that is required for or that potentiates its ability to cause disease
What are the steps in an infectious disease ?
- encounter
- entry
- spread
- Multiplication
- Damage
- Outcome
What are the three types of encounters that can occur?
exogenous
endogenous
congenital
What is an exogenous encounter?
out in the world
-sneeze, cough
What is an endogenous encounter?
a microorganism already present in the body moves to another area and causes issues
ex). organism normally present in the oropharynx is inhaled and colonizes in the lungs. this can cause pneumonia in the lungs
What is a congenital exposure?
exposure of mother to body during pregnancy or birth
What are the two types of entry of infectious disease?
ingress and penetration
What is ingress of an infectious disease?
inhalation or ingestion
What is penetration of infectious disease?
microbes pass through epithelia directly (attachment and internalization), insect bites, cuts and wounds, organ transplants and blood transfusions
What are the ways that infectious disease can spread?
lateral propagation- tissue to tissue
dissemination- travel far distances
What can affect the way that infectious diseases can spread?
anatomical factors (set up of sinuses)
active participation by microbes (if motile, pathogens can move far)
What can affect the multiplication of infectious disease?
environmental factors and subversion of host defenses
What are the possible outcomes of infectious disease?
microbe wins, host wins, or they learn to coexist
What is normal microbiota?
microbes frequently found on or within the bodies of healthy persons
When does colonization of bacteria begin?
rapidly after birth
-thousands of bacterial species are part of normal flora
How much of the human body mass is bacteria?
1-3%
What is the benefit to having normal microbiota?
-produce some vitamins we are unable to make on our own
-break down our food to extract nutrients
-teach immune system to recognize dangerous invaders
-make helpful anti-inflammatory compounds
-occupy space to crowd out disease causing bacteria
-detoxification of carcinogens
What parts of the bodies have the largest amounts of bacteria?
-skin
-respiratory tract
-digestive tract
-urinary tract
-genital system
What are the sterile locations of the body?
blood
cerebrospinal fluid
synovial fluid
deep tissues
What is periodontitis?
overgrowth of particular bacteria in gingival cervices
What is pneumonia?
defenses lowered and microaspirations of pneumococci
What bacteria is seen in catheter associated infections?
staphylococci
What does the oral flora include?
bacteria (archea)
fungi
protozoa
viruses
How many different species of bacteria are seen in the oral cavity?
around 700
What are the oral habitats for oral flora?
-buccal mucosa
-dorsum of tongue
-tooth surfaces
-crevicular epithelium
-dental appliances
What can cause issues for microbial cells?
-nutritional fluxes
-maintaining occupancy
-resistance to damage
What factors modulate the growth of bacteria in the oral cavity?
-anatomical features make it harder to clean
-shape and topography of teeth
-malalignment of teeth
-poor quality of restorations
-saliva
-crevicular fluid
How does saliva modulate the growth of bacteria in the oral cavity?
promote adhesion to the tooth surface
source of food
promote aggregation of bacteria
inhibit growth of microbes by nonspecific defense
maintain pH
What is an absolute requirement for all living organisms?
membranes
What are characteristics of plasma membrane
-contain lipids and proteins
-form bilayer
-proteins can be imbedded in the membrane of on the outside
-highly organized, asymmetric, flexible, and dynamic
What is the bacterial sterol that is present in the membrane?
hopanoid
What are peripheral proteins?
proteins loosely attached with the membrane and easily removed
What are integral proteins?
proteins embedded within the membrane and not easily removed
What are the functions of the plasma membrane?
separate the cell from the environment
selectively permeable
-some molecules allows to pass into and out of the cell (water)
-transport systems aid in movement of molecules
location of crucial metabolic processes
detection of and response to chemicals in surroundings
What are inclusion bodies?
granules of organic or inorganic material that are stockpiles by the cell for future use
What are ribosomes?
complex structures consisting of protein and RNA
sites of protein synthesis
-70s in prokaryotes
-80s in eukaryotes
What is the nucleoid ?
irregular shaped region of cell
location of chromosome
-usually 1 per cell
non-membrane bound
Are nucleoids always smooth membraned?
no, when the cells are actively growing, the nucleoids have projections
-these have DNA that actively being transcribed
What are characteristics of prokaryote chromosome?
closed, circular, double stranded DNA
looped and coiled
nucleoid proteins make help to fold DNA
What is a plasmid?
usually small, closed circular DNA molecules
-exist and replicate independently of chromosome
-not required for growth and development
-may carry genes that confer selective advantages (drug resistance)
What is the prokaryotic cell wall?
rigid structure that lies just outside the plasma membrane
What are the functions of the cell wall?
-provide characteristic shape to cell
-protects the cell from osmotic lysis (does not allow too much water to enter)
-may also contribute to pathogenicity
-may also protect cell from toxic substances
Does gram positive or gram negative have more peptidoglycan?
gram positive
What is the periplasmic space?
gap between the plasma membrane and cell membrane in gram positive OR space between plasma membrane and outer membrane in gram negative
What is the periplasm?
substance that occupies periplasmic space
What are some of the functions of periplasmic enzymes?
-nutrient acquisition
-electron transport
-peptidoglycan synthesis
-modification of toxic compounds
What are the two alternating sugars the form the backbone for peptidoglycan?
N-acetylglucosamine
N-acetylmuramic acid
What is unique about the peptidoglycan structure?
there are amino acids that are not typically present in proteins
-D-glutamic acid
-D-alanine
Where do cross links occur in gram negative bacteria?
D-Ala and DAP
Where do cross links in occur in gram positive bacteria?
D-Ala and L-Lys
What is also present in gram positive cell walls?
teichoic acids
What are teichoic acids?
polymers of glycerol or ribitol joined by phosphate groups
What are the characteristics of gram negative cell walls?
consist of a thin layer of peptidoglycan surrounded by an outer membrane
-outer membrane composted of lipids, lipoproteins, and lipopolysaccharides
-no teichoic acids
-have Brauns lipoproteins which may act like teichoic acids
What do teichoic acids do?:
help to anchor the NAG and NAM
What are adhesion sites?
sites of direct contact between plasma membrane and outer membrane
-substances may move directly into cell through these adhesion sites
What are the three parts of lipopolysaccharides?
Lipid A
core polysaccharide
O side chain
What is the importance of LPS?
-protection from host defenses (O antigen)
-contribute to negative charge of cell surface (core polysaccharide)
-help stabilize outer membrane structure (lipids A)
-can act as endotoxin (lipid A)
Which is more permeable: outer membrane or plasma membrane?
outer membrane
-there are more porin proteins and transporters that help to move things through
What are capsules?
usually composed of polysaccharides
well organized and cannot be removedc form cell
-outside the cell wall
What are slime layers?
similar to capsules except diffuse, unorganized, and easily removed
What is a glycocalyx?
network of polysaccharides extending form the surface of the cell
-capsule or slime layer made of polysaccharides can be referred to as a glycocalyz
What are the functions of capsules, slime layers, and glycocalyx?
-protection from viral infection or predation by bacteria
-protection form chemicals in the environment
-motility or gliding bacteria
-protection against osmotic stress
What are fimbriae?
short, thin, hairlike, proteinaceous appendages
-up to 1000 per cell
What are sex pili?
similar to fimbriae except longer, thicker and less numerous
1-10 per cell
-required for mating
What is monotrichous?
one flagellum
What is polar flagellum?
flagellum at end of cell
What is ampthitrichous?
one flagellum at each end of the cell
What is lophotrichous?
cluster of flagella at one or both ends
What is peritrichous?
spread over entire surface of cell
What are the three parts of flagellum?
filament
basal body
hoo k
What does the filament of the flagellum do?
project out of the cell surface
What does the basal body of the flagellum do?
anchor to the plasma membrane
What does the hook of the flagellum do?
gives bend to the overall structure
What is the bacterial endospore?
dormant form of bacteria
What is the purpose of an endospore?
makes the bacteria resistant to numerous environmental conditions
-heat, radiation, chemicals, desiccation
What are some differences between eukaryotic and prokaryotic cells?
eukaryotic cells …
-have a membrane bound nucleus
- have membrane bound organelles
-are more complex
-are generally larger
What is the endoplasmic reticulum?:
irregular network of branching and fusing membranous tubules and flattened sacs
What is the rough ER?
portion of the ER that has ribosomes bound
-is the location where secrete proteins by the ER are made
What is the smooth ER?
part of the ER that does not have ribosomes bound
-synthesis of lipids by ER associated enzymes
What are the overall functions of the ER?
transport proteins, lipids, and other materials within the cells
-major site of cell membrane synthesis
-synthesis of lysosomes and other organelles
What is the golgi apparatus?
membranous organelle made of cisternae stacked on each other
What are dictyosomes?
stacks of cisternae in the golgi
What is the golgi involved in?
modifying, packaging, and secreting of materials
What directions do things get processed through the golgi?
enter on the cis side travel to the trans side
What are lysosomes?
membrane bound vesicles
-contain hydrolytic enzymes needed for digestion of macromolecules
What is endocytosis?
uptake of solutes or particles by enclosing them in vesicles of vacuoles pinched off from the plasma membrane
What is phagocytosis?
ingestion of particles or bacterial cells (eating)
What is pinocytosis?:
ingestion of solutes (drinking)
What are mitochondria?
site of TCA activity
-site where ATP is generated by electron transport and oxidative phosphorylation
What is the matrix of the mitochondria?
cytoplasm equivalent
-contain ribosomes, mitochondrial DNA, and large Ca Phosphate granules
-contain enzymes of TAC cycle and beta oxidation pathway for fatty acids
What is a nucleus?
membrane bound structure that houses the genetic material of the cell
What is chromatin?
dense fibrous material within the nucleus
contain DNA
condense to form chromosomes during cell division
What are exoenzymes?
secreted by gram positive bacteria
-perform many of the same functions that periplasmic enzymes do for gram negative bacteria
