Microbiology Chapter 1: Introduction to Microbiology

Question 1

AGENTS OF MICROBIOLOGY: EUKARYOTES (YOU) AND PROKARYOTES

Answer 1

PROKARYOTES(unicellular,lack nucleus): Bacteria, Archaea,

EUKARYOTES(unicellular or multicellular, distinct nucleus): Protists, Fungi, Helminths, Animal, Plants

Question 2

WHAT IS THE GERM THEORY OF DISEASE?

Answer 2

-states that microbes cause infectious diseases

Question 3

WHO PROPOSED THE GERM THEORY OF DISEASE?

WHO PROVED IT?

Answer 3

• Louis Pasteur proposed the germ theory of disease( hypothesized that air contains contaminating microbes)
• Robert Koch proved the germ theory of disease (Koch’s postulates)

Question 4

KOCHS POSTULATES

Answer 4

1. same organism must be present in every case of disease
2. organism must be isolated from diseased host and grown as a pure culture
3. isolated organism should cause same disease when inoculated into susceptible host
4. organism must be re-isolated from the inoculated, diseased animal

Question 5

PASTEUR’S EXPERIMENT DISPROVING SPONTANEOUS GENERATION

Answer 5

• used an S-necked flask partially filled with broth and boiled the broth(it remained unspoiled because microbes in air were trapped in the bent portion of the flask, unable to reach the liquid)
• when the flask was shaken broth encountered microbes trapped in the curved neck and spoiled

Question 6

LEEWENHOEK

Answer 6

• refined earlier versions of the microscope (300x)
• first to see bacteria

Question 7

REDI

Answer 7

• performed experiments to test the hypothesis of spontaneous generation ( meat in jars)

Question 8

PASTEUR

Answer 8

• proposed germ theory of disease
• showed that biogenisis(life emerging from existing life) is responsible for propagation of life
• pasteurization of wine
• hypothesized that air contains contaminating microbes
• developed first vaccine against anthrax babies

Question 9

KOCH

Answer 9

• proved the germ theory of disease
• developed staining techniques and media
• Koch’s Postulates

Question 10

SEMMELWEIS(a.k.a SCRUB THEM HANDS BITCH)

Answer 10

• developed first aseptic techniques in the hospital setting
• recommended hand washing to decrease mortality rate from childbed fever

Question 11

LISTER(lister=listerine=sterilizing)

Answer 11

• investigated processes of aseptic surgery
• proved sterilizing instruments and sanatizing wounds prevented pus formations

Question 12

NIGHTINGALE=NURSING

Answer 12

• established aseptic techniques in nursing
• founder of modern nursing

Question 13

HOOKE (a hooker for them scopes)

Answer 13

• built early microscopes
• first to publish description of cells

Question 14

SNOW

Answer 14

• determined the cause of cholera transmission in London (contaminated water)

Question 15

THE SCIENTIFIC METHOD

Answer 15

1. observation
2. hypothesis (tentative explanation of phenomena)
3. experiment (tests a hypothesis)
4. result (data collected from experiment)
5. conclusion (supports or refutes hypothesis)

Question 16

SCIENTIFIC LAW

SCIENTIFIC THEORY

Answer 16

SCIENTIFIC LAW: precise statement or mathematical formula that predicts a specific occurence

SCIENTIFIC THEORY: an explanation of natural phenomena based upon a preponderance of overwhelming scientific evidence

Question 17

BRIGHT FIELD MICROSCOPY

Answer 17

• sample must be stained or have natural coloration
• illuminates species with cone of light
• bright background
• image formed based on how light is absorbed

Question 18

DARK FIELD MICROSCOPY

Answer 18

• negative image
• sample appears light on a dark background
• image formed base on how light is scattered
• visualizes stained and unstained specimens (alive or dead)

Question 19

PHASE CONTRAST MICROSCOPY

Answer 19

• negative image
• sample appears light on a dark background
• phase shifts that light experiences as it passes through a sample are converted into visible changes in brightness to provide richer shading and contrast
• visualizes unstained or stained specimens (dead or alive)

Question 20

DIFFERENTIAL INTERFERENCE CONTRAST

Answer 20

• false 3D appearance
• illuminates species with polarized light

Question 21

LIGHT MICROSCOPES

Answer 21

• use light waves
• color images possible
• provide a maximum of 1,000x
• resolution of 200 nm
• specimens can be living or dead
• stains often used/ can sometimes go without staining

Question 22

ELECTRON MICROSCOPES

Answer 22

• use an electron beam
• only black and white images
• can magnify over 500,000x
• specimens are all dead
• specimens often must be stained with osmium or gold

Question 23

SIMPLE STAINING

Answer 23

• use one dye
• size, shape, and cellular arrangement can be determined
• smear covered with methylene blue so dye can penetrate cells, then it is rinsed
• viewed with light microscope
• uses basic dyes mildly basic on the pH scale (positively charged)

Question 24

STRUCTURAL STAINING

Answer 24

• flagella(motility) staining
• capsule( sticky carbohydrate based structures) staining
• bacterial endospore(dormant structures made in response to stressful or harsh conditions) staining

Question 25

ACIDIC STAINING

Answer 25

- negatively charged - stain background of a specimen - do not easily enter cells

Question 26

GRAM STAINING

Answer 26

- one of the most important stains in microbiology - knowing gram property of a specimen has clinical implications including pathogenic features, what antibiotics might be most effective in combating it - shows chemical and structural differences between cell walls - gram positive bacteria remain purple/ gram negative bacteria are colorless - gram positive bacterial cell walls contain peptidoglycan (protein carbohydrate substance) and do not have an outer membrane (negative do)

Question 27

ACID-FAST STAINING

Answer 27

- distinguishes between cells with and without waxy cell walls - acid fast bacteria have waxy cell walls that are rich in a substance called myolic acid that retain the red colored primary dye even after exposed to an acid wash/ non acid-fast cells color is stripped away - detects myobacterium species -

Question 28

TAXONOMIC HIERARCHY

Answer 28

Delightful- domain King - kingdom Philip- phylum Came- class Over- order For- family Great- genus Spaghetti-species

Question 29

BINOMIAL NOMENCLATURE

Answer 29

- two name system - Genus is the first name (capitalized) - Species is the second name (lowercase) - scientific names are italicized

Question 30

3 DOMAINS OF LIFE

Answer 30

BACTERIA- unicellular, prokaryotic organisms ARCHAEA- some live in extreme environments EUKARYA- unicellular & multicellular eukaryotic organisms

Question 31

EUKARYOTIC KINGDOMS

Answer 31

- group of similar organisms that can sexually reproduce together

Question 32

PROKARYOTIC KINGDOM

Answer 32

- share physical characteristics and have at least 70% DNA similarity

Question 33

BIOFILMS

Answer 33

- sticky communities made up of a single or diverse microbial species - cells that seed a biofilm make adhesion factors to help them attach to a target surface - 60-80% of infectious diseases in humans are due to biofilm creating molecules

Question 34

QUORUM SENSING

Answer 34

-the collective sensing and responding to changes within a bacterial community

Question 35

ASEPTIC TECHNIQUE

Answer 35

- preventing the introduction of potentially dangerous microbes to a patient; it doesn't mean that everything in the healthcare setting needs to be sterile (absent of all microbes)

Question 36

CULTURE MEDIA

Answer 36

CULTURE MEDIA- mixtures of nutrients that support organismal growth in an artifical setting - agar - nutrient broth

Question 37

INTERSPECIFIC AND INTRASPECIFIC COMMUNICATION

Answer 37

INTERSPECIFIC: communication between different species of animals, plants, or microorganisms INTRASPECIFIC: occurs between members of the same species.