microbiology introduction

Question 1

7 groups of microorganisms

Answer 1

bacteria
archaea
fungi
protozoa
algae
small multicellular animals
viruses(?)

Question 2

prokaryotic cell

Answer 2

-no nucleus
-no membrane-bound organelles
-circular chromosomes
-asexual reproduction (binary fission)
-unicellular/colonial
-usually small

Question 3

bacteria

Answer 3

-peptidoglycan cell wall (some species lack cell wall)
-a few species are harmful to humans; most are neutral or beneficial

Question 4

what is the bacterial cell wall made of?

Answer 4

peptidoglycan

Question 5

arcaheans

Answer 5

-non-peptidoglycan cell wall
-ribosomal structure closer to eukaryotes
-often found in extreme environments
-none associated with disease
i..e methanogens (animal GI tract), extreme halophiles (super salty environment)

Question 6

5 eukaryotes

Answer 6

protists
algae
fungi
plants
animals

Question 7

2 prokaryotes

Answer 7

bacteria
archaea

Question 8

prokaryotes vs eukaryotes:

organization
size
type of nucleus
DNA
cell movement
membrane bound organelles

Answer 8

organization: usually unicellular vs unicellular, multicellular, colonies

size; smaller vs bigger

type of nucleus: none (its DNA housed in a ‘nucleoid’ region) vs proper nucleus with a double membrane

DNA: usually circular, vs linear chromosomes

cell movement; flagella (flagellin protein) vs cilia, pseudopodia

membrane bound organelles: none vs many

Question 9

fungi

Answer 9

-absorptive heterotroph
-cell wall made of chitin
-uni or multicellular
-hypae (rods) for bisexual and asexual spores to reproduce
or reproduce by budding cells

Question 10

what is fungi cell wall made of

Answer 10

chitin

Question 11

fungi, protozoans, animals, algae :

ingestive heterotroph or absorptive heterotroph or photosynthetic autotroph

Answer 11

fungi- absorptive

protozoans- ingestive
animals- ingestive

algae- photosynthetic autotroph

Question 12

ingestive vs absorptive heterotrophs

Answer 12

Fungi are absorptive heterotrophs: they secrete digestive enzymes that break down polymers to monomers which are absorbed across the cell wall and cell membrane.
-i.e. absorb pre-digested nutrients

Animals are ingestive heterotrophs: they eat their food and digest it in a compartment within their bodies.

Question 13

protozoans

Answer 13

NOT PROTISTS
-single cells eukaryotes
-ingestive heterotrophs (like animals)
-often sorted according to motility: cilia, flagellum, pseudopodia

Question 14

how protozoans can move (3)

Answer 14

cilia, flagellum, pseudopodia

Question 15

algae

Answer 15

-uni or multicellular eukaryotes
-photosynthetic autotroph
-categorized on the basis of their pigmentation and the composition of their cell walls
-multicellular: seaweed and kelp; no roots; all tissues are photosynthetic

Question 16

animals

Answer 16

ingestive heterotroph
-adults visible but larvae are microscopic

Question 17

hippocrates

Answer 17

400BC; link between environment and disease

-Thucydides notes plague survivors cannot get the same disease twice

Question 18

Robert Hooke (1650s)

Answer 18

founder of cell biology
-introduced the notion that cells were the fundamental unit of life
-coined the term “Cell” due to resemblance of honeycomb cells

Question 19

who was the founder of cell biology

Answer 19

Robert hooke

Question 20

who was the founder of microbiology

Answer 20

antonie van leeuwenhoek 1670s

Question 21

antonie van leeuwenhoek 1670s

Answer 21

founder of microbiology
-first reported existence of most types of microorgansims

Question 22

antonie van leeuwenhoek discovered what?

Answer 22

protists: any eukaryotic organism that is not an animal, plant or fungus

also vertebral sperm cells

-spermatozoa
-muscle fibers
-RBCs

Question 23

who discovered protists

Answer 23

antonie van leeuwenhoek

Question 24

who discovered sperm cells

Answer 24

antonie van leeuwenhoek

Question 25

carolus linnaeus (1735) founded what

Answer 25

taxonomics: a system for naming species and grouping similar ones togehter
-linnaeus described two groups; plants and animals

Question 26

who founded taxonomics

Answer 26

carolus linnaeus

Question 27

what was carol’s linnaeus’ hierarchical (linnaen) classification

Answer 27

7 levels- taxon
-binomial nomenclature: genus, species

species –> genus –> family –> order –> class –> phylum –> kingdom

Question 28

how did Aristotle think life emerged

Answer 28

from biogenesis or spontaneous generation

-life emerging from non-living matter

Question 29

what is abiogenesis

Answer 29

spontaneous generation
-life emerging from non-living matter

Question 30

who put abiogenesis/ spontaneous generation into question and what was the experiment?

Answer 30

Fransisco redi
-flask unsealed vs sealed vs covered with gauze
-piece of meat
-only when flies could get in then maggots would be on meat

Question 31

was John Needham for or against spontaneous generation; what was his experiment

Answer 31

for

he put clear broth in flask, sealed it, boiled it

-as he explained it “there must be a “life force” that causes inanimate matter to spontaneously come to life because he had heated the vials sufficiently to kill everything”

Question 32

what experiment disproved spontaneous generation?

Answer 32

Pasteurs swan necked flask experiment

-heated flask, let steam escape from flask and air can move in and out but the dust won’t get in so it remains sterile

no microbes appear

Question 33

pasteur and fermentation; what causes fermentation, what causes spoiling?

Answer 33

fermentation of grape juice into wine via yeast

spoiling via bacterial microbes

Question 34

pasteur- pasteurization

Answer 34

pasteurization: heat grape juice just enough to kill most bacteria without ruining the juices taste and other qualities

Question 35

what was the germ theory of disease and who’s theory was it

Answer 35

pasteur

germ theory: microorganisms are also responsible for disease. each disease is caused by a specific germ (pathogen)

diseases caused by germs are no called infectious diseases

Question 36

who studied the etiology of infectious disease and how was it done

Answer 36

Robert koch
-simple staining techniques
-first photomicrograph of bacteria
-first photograph of bacteria in diseased tissue
-use Petri dish to hold solid growth media
-transferring bacteria with heat and metal wires
–> agar

Question 37

koch’s postulates (4)

Answer 37

1. the suspected causative agent must be found in every case of the disease and be absent from healthy cases
2. the agent must be isolated and grown outside the host
3. when the agent is introduced to a healthy, susceptible host, the host must get the disease
4. the same agent must be found in the diseased experimental host

Question 38

prevention of disease

Answer 38

1. hand washing (Ignaz Semmelweis)
2. antiseptic technique and disinfection (Joseph lister)
3. disinfect room and clothes (Florence nightingale)
4. John snow: correlated cholera propagation with poor water sanitation led to infection control and epidemiology studies
5. variolation- vaccine against smallpox

Question 39

variolation

Answer 39

• vaccine against smallpox

problem: smallpox
-caused by two viral variants: variola major and variola minor
-die less with minor
-so inject with minor

Question 40

Jenners vaccine

Answer 40

jenner observed that milkmaids dont get smallpox

injected 8 yr old boy with pus from milkmaids cowpox blisters

inject him w variola major