Part 1 - Microbiology And Microorganisms Flashcards Preview

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Flashcards in Part 1 - Microbiology And Microorganisms Deck (58):
1

Microbiology is defined by what techniques

Culture media for isolation and growth of an organism in pure culture
Biochemical to study cell components
Molecular and genetic techniques

2

Oldest form of life

Microbes

3

Largest mass of living material on earth

Microbes

4

Why is microbiology important?

Carry out major processes for biochemical cycles
Can live in places unsuitable for other organisms
Other life forms require microbes to survive

5

All cells have

Cytoplasmic membrane
Cytoplasm
Ribosomes

6

Cytoplasmic membrane

Barrier that separates the inside of the cell from the outside

7

Cytoplasmic

Aqueous mixture of macromolecules, ions, and proteins

8

Ribosomes

Site of protein synthesis

9

Genetic material

Stored as DNA
Information is divided into functional units called genes

10

Genome

A cell's full complement of genes

11

Plasmid

Piece of DNA that carries non-essential genes

12

Eukaryotes have

Membrane bound nucleus
Membrane bound organelles
Complex internal organization
Division by mitosis and meiosis

13

Protists

Unicellular or multicellular without differentiation into tissues

14

Types of protists

Protozoa
Algae
Slime molds

15

Protozoa

Animal-like microorganisms

16

Algae

Photosynthetic plant-like microorganisms

17

Slime molds and water molds

Filamentous

18

Fungi

Unicellular - yeasts
Filamentous- molds
Multicellular- mushrooms

19

Prokaryotes

No membrane bound nucleus or organelles
Generally smaller 1 micrometer
Simple internal structure
Divide by binary fission
Most are unicellular

20

Bacteria

Genetically diverse
Extremely diverse metabolic styles
Both pathogens and non-pathogens

21

Archaea

Genetically and biochemically distinct from bacteria
Diverse metabolism
Never pathogenic
Live in extreme environments

22

Viruses

Acellular infectious particles
Extremely small
Obligate intercellular parasites
Lack independent metabolism- no ribosomes, no ribosomal DNA, not classified with other microbes

23

First anaerobic life

Between 3.8 and 3.9 billion years ago

24

Photosynthetic bacteria oxygenated the earth

2 billion years ago

25

What allowed the evolution of modern eukaryotic microorganisms?

Oxygenation of the earth

26

First plants and animals appeared

0.5 billion years ago

27

Prokaryotes ribosomes

70s and 16S ssu rRNA

28

Eukaryotes ribosomes

80s and 18s ssu rRNA

29

rRNA

Change slowly over time
Examine genetic differences rather than morphological differences

30

Basic steps involved in sequencing rRNA genes

Step 1 - DNA is collected from a pure culture
Step 2 - the SSU rRNA is amplified using polymerase chain reaction
Step 3 - gene is sequenced
Step 4 - sequence is aligned with sequences from other organisms
- number of differences is used to calculate evolutionary distance

31

PCR

A technique used to synthesize many identical copies of a short sequence of DNA

32

Phylogenetic tree

A graphic representation of the evolutionary distance between organisms

33

Phylogenetic tree based on

16S or 18S ribosomal DNA sequences

34

Most genetically diverse

Microorganisms

35

Phylogenetic species concept

A group of strains that share certain diagnostic traits, are genetically cohesive and have a unique recent common ancestor

36

Species of bacteria and archaea should have

Most characteristics in common
Greater than 97% sequence similarity in the 16S rRNA gene
High degree of genome similarity
- DNA-DNA hybridization

37

Hierarchical classification

Groups of organisms are placed in successively larger groups
Species, genus, phylum

38

Robert Hooke

First to describe microbes

39

What is microbiology?

Study of organisms too small to be seen with the naked eye

40

What kind of microscope did Robert Hooke use?

Compound microscope with 2 lenses with up to 30x magnification

41

What did Robert Hooke observe?

Cells in cork
Bread mold filaments

42

What was the first microbe observed?

Bread mold filaments

43

Cell Theory

All living things are composed of cells

44

Antoni van Leeuwenhoek

Built microscopes that magnified by 50-300x
Observed single called microorganisms, "animalcules" - first discovery of bacteria

45

Louis Pasteur

Studied wine and beer production

46

Fermentation

Yeast will convert sugar to alcohol without oxygen

47

Souring wine is caused by

Bacteria converting alcohol to acid

48

Pasteurization

Gentle heating to kill unwanted bacteria

49

Pasteur and Spontaneous Generation

- Prepared meat infusions inside of long swan-necked flasks
- Boiled the infusion to sterilize it
- As long as the flask remains upright, dust, and microbes cannot enter, and the infusion remains sterile

50

Aseptic technique

Methods for controlling the growth of microorganisms

51

What did Robert Koch study?

Anthrax - responsible for epidemics in livestock

52

Koch's postulates

Established set of criteria for relating a specific microbe to a disease

53

Broth medium solidified with agar

Polysaccharide derived from marine algae

54

What temperature does agar melt at?

97c

55

What temperature does agar solidify at?

43c

56

Typical Petri plate

Nutrient broth medium + 1.5% agar

57

Colony

Mass of cells that (ideally( rose from one single cell

58

Significant and insignificant numbers

300 - inaccurate count