Intro - Lecture 1 Flashcards
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
Are bacteria prokaryotic or Eukaryotic?
Multicellular or unicellular?
Prokaryotic
Unicellular
How are bacteria classified?
Classified by biochemical and morphological characteristics
Are parasites prokaryotic or Eukaryotic?
Multicellular or unicellular?
Eukaryotic
Unicellular and multicellular
How are parasites classified?
Classified based on life cycle and structure
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
Are fungi prokaryotic or Eukaryotic?
Multicellular or unicellular?
Eukaryotic
unicellular and multicellular
How are fungi classified?
Classified by location of infection
Where do most fungal infections occur?
Where else do fungal infections exist?
Mostly occur superficial or cutaneous
Also exist subcutaneously and systemically
Give some examples of fungal infections.
Candidiasis - yeast infection, thrush
Dandruff
Athlete’s foot
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
Give five characteristics of prokaryotes
Unicellular One cellular membrane No organelles Replicate by binary fission Bear a haploid genome (one copy)
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)
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
How do bacteria replicate?
Binary fission
How are bacteria classified?
Domain Kingdom Phylum Class Order Family Genus Species Strain Serotype/Serovar
What is the difference between bacteria of different species?
They bear major genetic differences
What is the difference between bacteria of different strains?
They are genetically distinct
What is the difference between bacteria of different serotype/serovar?
The are serologically different (H__:N__)
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.
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
What colour are the gram positive bacteria?
Violet
What colour are the gram negative bacteria?
Pink
What are the 6 classis gram positive bacteria?
Streptococcus Staphylococcus Bacillus Clostridium Corynebacterium Listeria
What is the diplococcus gram negative bacteria?
Neisseria
What are some examples of gram negative bacteria?
Neisseria
Enterobacteria (E. coli)
Pseudomonas
Salmoonella
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
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
Describe obligate aerobic bacteria
Require oxygen for growth
Possess all three enzymes
Describe facultative anaerobes
Can grow in the absence of oxygen - use fermentation
But prefer oxygen
Possess Catalase and superoxidase dismutase
Describe microaerophilic bacteria (aerotolerant anaerobes)
Use fermentation
But can tolerate low amounts of oxygen
Possess superoxide dismutase
Describe obligate anaerobe bacteria
Hate oxygen
Posses no enzymes to defend against oxygen
What can culturing bacteria in different media reveal?
1) Colony morphology - distinguish between specias
2) Colony growth
3) Enzymatic activity
What does Bloor agar detect when culturing bacteria?
Haemolysis
What does Lactose-containing agar detect when culturing?
Detects lactose fermentation
Where do thermophile bacteria thrive?
Give an example
Thrive in hot environments
Thermus aquaticus
Where do acidophile bacteria thrive?
Give an example
Thrive at low pH
Acetobacter aceti
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)
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
