N251 Exam 1 (lectures 1-3)

What's the professor's name?

Allen W. Davidson

What are microorganisms?

~ range in size (smallest - virus; largest - parasites and fungi)

~ can be prokaryotic or eukaryotic

What is a prokaryote (prokaryotic)?

means "pre-nucleus"; no membrane bound organelles

~ EX: bacteria

What is a eukaryote (eukaryotic)?

means "true-nucleus"; possess membrane bound organelles

~ EX: parasites, amoeba, paramecium, man

structure of a bacterial cell: flagellum

provides motility

structure of a bacterial cell: fimbria

small bristle like fibers on a surface. helps bacteria stick to ea. other and surfaces

structure of a bacterial cell: pillus

elongated, rigid tubular structure; used for sexual reproduction (aka conjugation)

~ conjugation - transfer DNA from 1 cell to another. donor and receiver. donor extends it's pillus into receiver and begins to procreate (pass on DNA) > receiver and donor splits > receiver becomes a donor

structure of a bacterial cell: cell envelope

composed of the glycocalyx, cell wall, and cell membrane. protects the cell

structure of a bacterial cell: gylcocalyx

outermost layer of cell; a coating of macromolecules. protects the cell and helps cell adhere to its environment. can be different among bacteria. can have 2 layers (slime and capsule)

structure of a bacterial cell: gylcocalyx coatings

~ slime: loose, soluble polysaccharide; not bound to the cell; aids bacteria in colonizing surfaces (attaches to surface)

~ capsule: bound to cell; has a thick, gummy consistency; makes bacteria more virulent (protects bacteria from phagocytosis); prevents bacteria from drying out; aids in attachment for colonization

What's the difference between a glycocalyx slime coating and a glycocalyx capsule coating?

slime = loose; not bound to cell; slide across surface

capsule = thick consistency; bound to cell; protect against host's immune system

What kind of glycocalyx coating does Klebsiella pneumoniae have? And what characteristics does it have?

~ capsule coating

~ gives bacterial colonies a sticky, mucoid characteristic

structure of a bacterial cell: cell wall

middle layer - rigidity and structure; gives bacteria shape and protection (differences in cell wall chem. composition determines gram staining properties); helps prevent cell from bursting/collapsing due to changes in environment (stops H2O from going into cell - equilibrium); site of action of some of most effective antibiotics

structure of a bacterial cell: cell wall chemical structure

composed of peptidoglycan. only found in bacteria (similar to chitin on lobster, insects; hard shell)

structure of a bacterial cell: cell membrane

is on actual bacteria (surrounds cell itself) - flexible skin; holds cell together; controls things moving in and out of cell; structure - phospholipids w/ proteins; some areas of membrane fold inward forming mesosomes = folding increases surface area (most chem. needed for biochemical reactions are located on membrane)

structure of a bacterial cell: protoplasm

inside of cell = blood of the bacterial cell (contains 70-80% H2O, sugars, amino acids, salts, enzymes, chromatin body, ribosomes, mesosomes, and granules). site of biochemical and synthetic activity.

structure of a bacterial cell: chromatin body

bacterial chromosome. DNA aggregates in dense area called the nucleoid w/ no membranes surrounding it

structure of a bacterial cell: plasmid

circular piece of DNA (extrachromosomal strand) - outside chromosome. protective f(x) - provides resistance to drugs. advantage to man - uses in genetic engineering techniques. involved in anabolic resistance

structure of a bacterial cell: ribosomes

used in protein synthesis

structure of a bacterial cell: inclusion granules

concentrate nutrients inside the cell, storage, and are not permanent. a storage unit for extra nutrients

What is phagocytosis?

engulfs and destroys microorganisms

What is chemotaxis?

chemical attraction of phagocyte to bacterium. chemical attractants are microbial products, components of damaged tissue, and products of complement system

What is adherence?

attachment of a phagocyte plasma membrane to microorganisms

What are the steps of phagocytosis?

chemotaxsis > adherence > opsonins > ingestion > digestion > excretion.

phagocytosis: ingestion

plasma membrane of phagocyte extends out projections called pseudopods that surround microbe. forms sac called phagosome

phagocytosis: digestion

phagosome comes in contact and fuses w/ lysosomes that contain digestive enzymes & bactericidal substances. forms a larger vacuole aka phagolysosome. ingested bacteria are killed. phagolysosome moves to cell membrane

phagocytosis: excretion/exocytosis

elimination of digested contents (waste)

gram positive cell wall

THICK layer of peptidoglycan associated w/ teichoic acid. retain crystal VIOLET stain (purple stain)

Mordent

joins with crystal stain which makes the molecule bigger.

gram negative cell wall

THIN layer of peptidoglycan. outer membrane and periplasmic space. crystal violet-mordant molecule can escape when decolorized (light pink stain). turns pink when safranin is added.

gram staining steps **

1. application of crystal violet (purple dye)

2. application of mordent (iodine)

3. alcohol wash (decolorization)

4. application of safranin (counterstain - pink dye)

gram staining procedure ***

1. apply primary stain (stains all bacteria) rinse btwn EACH application*

2. apply mordent - binds w/ the stain inside the cell wall making a larger molecule

3. decolorize w/ acetone/alcohol - causes the stain to escape some bacterial cell walls rendering them unstained/colorless

4. add a counterstain - (safranin) this adds color to the cells that were decolorized

crystal violet

primary stain (purple)

gram's iodine

mordent (makes molecules "look" bigger)

acetone alcohol

decolorizer

safranin

counterstain (light pink)

which antibiotics inhibited cell wall synthesis?

beta-lactams, glycopeptides, bacitracin

which antibiotics inhibited protein synthesis (attacked how proteins are made)?

chloramphenicol, macrolides, aminoglycosides

which antibiotics caused membrane integrity lesions?

polymyxin

which antibiotics caused inhibition of replication and transcription? (affects bacterial reproduction)

quinolones, rifampicin

which antibiotics inhibited synthesis of essential metabolites (inhibit how bacteria would metabolize)?

sulfonamide, trimethoprim

characteristics of gram positive

1 layer. thick (20-80nm). no outermembrane. some have a periplasmic space. chem comp = peptidoglycan, teichoic acid, & lipotechoic acid. no porins proteins. has less lipids. has more peptidoglycan. more penetrable. less resistant to molecules

characteristics of gram negative

2 layers. thin (8-10nm). present outermembrane. periplasmic space in present in all. chem comp = lippolysaccharide, lipoporteins, & peptodoglycan. present porins proteins. has more lipids. has less peptidoglycan. less penetrable. more resistant to molecules

bacterial shapes: coccus

circular shape

bacterial shapes: streptococcus

chain shape

bacterial shapes: staphylococcus

forms masses (looks like a bunch of grapes)

bacterial shapes: diplococcus

usually in pairs of 2 (may look likes 4s bc of binary division)

bacterial shapes: tetrad

fours

bacterial shapes: sarcina

cube form

bacterial shapes: bacillus

rod shape

bacterial shapes: diplobacillus

pairs of 2 rods

bacterial shapes: streptobacillus

chains of rods

bacterial shapes: coryneform bacillus

look like they have a kink to them

bacterial shapes: spirillum

rob spiral shaped (elongated)

bacterial shapes: vibrio

curved rod

bacterial shapes: spriochete

long ribbon

infection terminology: transmissible

infectious disease agent that's transmitted from either a reservoir or a portal of exit to another host's portal of entry. the disease is transmitted through: contact transmission, vehicle transmission, or vector transmission

infection terminology: contact transmission

~ direct: person-to-person (kissing, touching, sexual, etc)

~ indirect: 1 host to another by fomites (inanimate objects - needles, toothbrushes, drinking glasses, etc)

~ droplet: droplets of mucus that exit mouth/nares during exhaling, coughing, and sneezing (cold/flu)

what are fomites?

objects or materials which are likely to carry infection, such as clothes, utensils, and furniture.

infection terminology: vehicle transmission

the spread of pathogens via air, drinking water, and food. blood and bodily fluids handled outside the body can be considered ______ too. (EX: airborne, waterborne, foodborne, blood & body fluids)

infection terminology: vector transmission

animals that transmit diseases from 1 host to another (biological or mechanical)

infection terminology: biological vectors

affects humans through biting arthropods (mosquitoes, ticks, lice, fleas, mites)

infection terminology: mechanical vectors

animals that passively carry pathogens to new hosts on their feet or other body parts (houseflies, cockroaches)

infection terminology: epidemic

appearance of infectious disease or condition which attacks many people @ THE SAME TIME IN THE SAME GEOGRAPHICAL LOCATION (flu, poison)

infection terminology: pandemic

epidemic that occurs simultaneously on MORE THAN 1 CONTINENT (AIDS, H1-N1, H5-N1 flu); bigger, covers large wide areas

infection terminology: endemic

a disease peculiar and RECURRING CONTINUOUSLY in a PARTICULAR LOCALITY or POPULATION (histoplasmosis- Ohio valley); disease that was already in location

infection terminology: contagious

a communicable disease that's easily transmitted from a reservoir or person (common cold, legionnaires disease)

infection terminology: epidemiology

the study of the occurrence, distribution, and spread of disease in humans (tracking SARS, bird flu (H5-N1), seasonal flu). epidemiologists track outbreaks of diseases through incidence and prevalence.

infection terminology: (epidemiology) incidence

the number of NEW CASES of a disease in a given area or population during a given period of time

infection terminology: (epidemiology) prevalence

the TOTAL NUMBER of cases, new and existing in a given area or population during a given period of time

how are microorganisms our FOE?

~ 750 mil. infectious diseases/yr worldwide

~ >200,000 deaths annually in US

~ tens of billions of $$ in health care

~ leading cause of illness and death (respiratory and diarrheal diseases)

how are microorganisms our FOE?: reasons for rise in infectious diseases

1. due to travel (1 in 5 come from a country where infectious diseases are common)

2. lax in vaccinating children b/c the disease in no long prevalent

3. use of medication to prolong life (w/ aging population; weaker immune sys. tend to get opportunistic infections)

4. development of drug resistance

when and where was the last small pox case? what is small pox?

1977 in Somalia. viral diseases that killed 10 mil and has a worldwide vaccination

what is the bubonic plague?

bacterial infection that happened during 1346-1350; 1/4 of the entire population in Europe died; now < 100 people/yr get infected

what is TODAY'S epidemic?

AIDS

facts about AIDS:

33 mil infected worldwide; >16 mil since beginning of epidemic; leading cause of death among 25-44y/o men; 2nd leading cause of death among 15-44y/o females; highest #'s from Africa, SE Asia, and central America

what are the names of common food borne outbreaks?

salmonella, shigella, E. coli, staph, bacillus cereus, clostridium (botulinum & perfringens), listeria, and noro virus

how are microorganisms our FRIENDS?

1. breakdown food in gut

2. produce foods: yogurt, cheese, wines, breads, sauerkraut

3. used to make: vitamins, insulin, drugs

4. decompose waste

5. recycle nutrients back into the earth

6. used as a food source for other organisms

7. make chem. products: acetone, glycerin, organic acids, enzymes, & alcohols

8. agriculture (helps some vegetables/fruits grow)

laboratory terms: broth

a liquid medium that contains various nutrients & is used to culture bacteria and other microorganisms in culture

laboratory terms: agar

a gelatinous material derived from algae, specifically used as a culture medium of bacteria and other cells for diagnostic or laboratory experiment purposes. agar is a gel @ room temp til 65°C; melts @ approx. 85°C; solidifies @ 32-40°C (property known as hysteresis)

laboratory terms: media w/ agar: deep

used for a culture where you need a DEEP inoculation into a solid medium (gelatin or agar) that's used especially for the growth of anaerobic bacteria

laboratory terms: media w/ agar: slants

a culture made on the slanting surface of a solidified medium in a test tube that has been tilted to provide a greater area for growth

laboratory terms: media w/ agar: plates

a petri dish that contains a solid growth medium, typically agar plus nutrients, used to culture small organisms such as microorganisms

define inoculate

treat (a person or animal) with a vaccine to produce immunity against a disease. introduce (cells or organisms) into a culture medium

laboratory terms: incubation

act of maintaining controlled environment conds. for the purpose of FAVORING growth or development of microbial cultures

laboratory terms: colony

a visible mass of microorganisms all originating from A SINGLE mother cell; therefore a colony constitutes a clone of bacteria all genetically alike

laboratory terms: picking colonies

selecting a colony from a plate and transferring it to another media or slate

laboratory terms: loop

a simple tool used by microbiologists to retrieve an inoculum from a culture of microorganism; it is used in the cultivation of microbes on plates by transferring inoculum for streaking

laboratory terms: needles

used in field of microbiology to transfer and inoculate living microorganisms; 1 of the most commonly implicated biological lab tools and can be disposable/reusable

laboratory terms: bunsen burner

a small adjustable gas burner used in laboratories

what 2 muppets does the professor talk about?

dr. bunsen honeydew and beaker

define metabolism

general term used for all of the reactions occurring in cells

define anabolic reaction (anabolism)

• simple substance is built into a complex substance (A for Adding); creating more complex molecules

• making larger molecules from smaller ones

• molecules are making structures that it'll be able to use

• building requires energy that comes from ATP molecules produced during catabolism (uses ATP)

define catabolic reaction (catabolism)

• start w/ a complex molecule and break it down and release energy (C for cutting); cutting the big molecule into small molecules

• degradation of food stuff

• energy is released and stored as ATP

• breakdown of large molecules to produce smaller molecules and release/create energy

what are the characteristics of an enzyme?

• protein molecules that act as catalysts - increases the rate of reaction that would normally occur @ a slow rate; it works w/ a specific substrate; substrate fits into the enzyme active site; lock & key fit = lock is the ________ & key is the substrate

• doesn't permanently change - can be reused again (increases the rate of reaction)

more characteristics about enzymes?

lowers activation energy;

EX: tell student to get up from seat > student slowly gets up > point a flame @ a student > student gets up faster > flame doesn't change > flame is ready to be used on another student

define activation energy

the amount of energy needed to trigger a chemical reaction

• EX: student gets up from chair > it'll be slow but eventually student will

activation energy w/ and w/o enzymes

substrate has higher energy than the products; once activation energy is reach, the reaction proceeds

• a reaction w/ enzymes are happen quicker b/c the enzyme lowers the amount of activation energy that's needed for the reaction

naming enzymes

______ are named after the substrate or the kind of reaction they catalyze;

• usually ends w/ the suffix "-ase"

• some enzymes still go by their old names (EX: trypsin; pepsin)

pathways for producing energy form nutrients (glucose): fermentation (reduction)

the final acceptor in the pathway is an organic molecule - pyruvic acid; doesn't use O2 bc it's made in the pathway itself; produces LESS energy from glucose (less efficient way of producing energy)