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2nd year - Microbiology > Intro - Lecture 1 > Flashcards

Flashcards in Intro - Lecture 1 Deck (39):
1

Describe the characteristics of a living organism (6 qualities that must be there)

1) Organization - cellular or molecular level
2)Metabolism - use energy to carry out functions
3) Growth - replication and enlargement
4) Adaptation - evolution of traits that increase fitness
5) Response to stimulus - evolution of traits that increase fitness and/or maintain homeostasis
6) reproduction

2

Are bacteria prokaryotic or Eukaryotic?
Multicellular or unicellular?

Prokaryotic
Unicellular

3

How are bacteria classified?

Classified by biochemical and morphological characteristics

4

Are parasites prokaryotic or Eukaryotic?
Multicellular or unicellular?

Eukaryotic
Unicellular and multicellular

5

How are parasites classified?

Classified based on life cycle and structure

6

Most human parasite pathogens affect what part of the body?
Give some example pathogens

Most human pathogens affect the GI tract and the blood
-malaria
-helminths and worms
-amoeba

7

Are fungi prokaryotic or Eukaryotic?
Multicellular or unicellular?

Eukaryotic
unicellular and multicellular

8

How are fungi classified?

Classified by location of infection

9

Where do most fungal infections occur?

Where else do fungal infections exist?

Mostly occur superficial or cutaneous

Also exist subcutaneously and systemically

10

Give some examples of fungal infections.

Candidiasis - yeast infection, thrush
Dandruff
Athlete's foot

11

Give some characteristics of prions
and some examples

Non-living
Acellular, made up of protein
Transmissible, misfolded protein
-Bovine spongiform encephalopathy
-Kreutzfeld-Jakob disease
-Kuru

12

Give five characteristics of prokaryotes

Unicellular
One cellular membrane
No organelles
Replicate by binary fission
Bear a haploid genome (one copy)

13

Give five characteristics of eukaryotes

Unicellular and multicellular
Multiple membranes
Multiple membrane-bound structures (nucleus, mitochondria, ER, golgi, lysosomes etc.)
Replicate by mitosis
Bear a haploid or diploid genome (one or two copies)

14

What are six things bacteria cells need to stay alive?

1) Genetic material
- Nucleoid DNA
- Plasmid DNA
2) Replication machinery
- DNA-dependent DNA polymerase
3) Gene expression
- Trascription: DNA-dependent RNA polymerase
- Translation: Ribosomes
4) Structural integrity
- Cell wall (some exceptions)
5) Motility
- Flagella, cilia, pili
6) Friends
- Genetic diversity
- Biofilms

15

How do bacteria replicate?

Binary fission

16

How are bacteria classified?

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Strain
Serotype/Serovar

17

What is the difference between bacteria of different species?

They bear major genetic differences

18

What is the difference between bacteria of different strains?

They are genetically distinct

19

What is the difference between bacteria of different serotype/serovar?

The are serologically different (H__:N__)

20

What are four major different morphologies of bacteria?
Name a few more

Cocci - round
Bacilli - rod-shaped
Sphirochetes - spiral
Vibria - curved rod
Helical, filamentous etc.

21

What does a gram stain detect and what are the two dies used?

Detects peptidoglycan
Crystal violet is the primary stain
Safranin is the counterstain

22

What colour are the gram positive bacteria?

Violet

23

What colour are the gram negative bacteria?

Pink

24

What are the 6 classis gram positive bacteria?

Streptococcus
Staphylococcus
Bacillus
Clostridium
Corynebacterium
Listeria

25

What is the diplococcus gram negative bacteria?

Neisseria

26

What are some examples of gram negative bacteria?

Neisseria
Enterobacteria (E. coli)
Pseudomonas
Salmoonella

27

What are the three exceptions to gram stain bacteria?

1) Acid-fast bacteria - Mycobacteria
-These are weakly gram-positive but stain better with the acid-fast stain
-Include organisms that cause TB and leporsy

2) Spirochetes
-These have a gram negative cell wall, but do not stain/are too small to be seen under light microscopy
-Visulaized with darkfeild microscope

3) Bacteria lacking cell walls - Mycoplasm, ureoplasma

28

What are three enzymes bacteria might have to break down oxygen products?

1) Catalase - breaks down hydrogen peroxide to water and oxygen
2) Peroxidase - breaks down hydrogen peroxide
3) Superoxide dismutase - breaks down the superoxide radical to hydrogen peroxide and oxygen

29

Describe obligate aerobic bacteria

Require oxygen for growth
Possess all three enzymes

30

Describe facultative anaerobes

Can grow in the absence of oxygen - use fermentation
But prefer oxygen
Possess Catalase and superoxidase dismutase

31

Describe microaerophilic bacteria (aerotolerant anaerobes)

Use fermentation
But can tolerate low amounts of oxygen

Possess superoxide dismutase

32

Describe obligate anaerobe bacteria

Hate oxygen
Posses no enzymes to defend against oxygen

33

What can culturing bacteria in different media reveal?

1) Colony morphology - distinguish between specias
2) Colony growth
3) Enzymatic activity

34

What does Bloor agar detect when culturing bacteria?

Haemolysis

35

What does Lactose-containing agar detect when culturing?

Detects lactose fermentation

36

Where do thermophile bacteria thrive?
Give an example

Thrive in hot environments
Thermus aquaticus

37

Where do acidophile bacteria thrive?
Give an example

Thrive at low pH
Acetobacter aceti

38

How does bacteria gain genetic diversity if they replicate via binary fission?

1) Mutation
2) DNA rearrangements (transposition, recombination)
3) Horizontal gene transfer (conjugation, transformation, transduction)

39

What are the six major bacterial groups?

1) Gram-positive cocci and rods
2) Gram-negative bacteria
3) Enteric bacteria (mostly gram-negative)
4) Acid-fast bacteria (ie. Mycobacteria)
5) Mycoplasma and ureaplasma
6) intracellular bacteria