Microbiology 1 -Prokaryotes Inside and Out Flashcards
Antibiotics can be used to treat bacterial infection. TRUE or FALSE
TRUE
List 5 things bacteria should be able to do, to be classed as Pathogenic
1) Gain access to the host
2) Evade hosts defence mechanism
3) Colonise and maintain colony
4) Result in host toxicity or damage
5) Potential for spread of infection
State some key features of a Prokaryote Cell
- Rigid and Complex cell wall (w/Appendages)
- Simpler structure and smaller size than an eukaryotic cell
- NO membrane -bound organelles (Nuclues, ER, Golgi, Mitochondria)
- Single Circular DNA
- Plasmid DNA = free in cytoplasm
- Enzymes and Ribosomes also free in cytoplasm
Name 2 functions of Flagella
1) Motility
2) Acts as a Sensory Organelle
Name the function of Fimbriae and Pili
- Cell Adhesion
What is the importance of Sex Pili ?
Important for movement of DNA b/wn cells by Conjugation
What is Conjugation ?
Transfer of genetic material b/wn bacterial cells by direct cell to cell contact
or; by bridge-like connection b/wn cells
What is the main function of a bacterial Capsule ?
- For Protection
State the 2 main functions of the Cell wall of a prokaryotic cell ?
- Provide structure to the cell
- Maintain positive internal osmotic pressure
Cell wall contains Peptidoglycan. TRUE or FALSE
TRUE
What is Peptidoglycan comprised of ?
Disaccharides + Amino acids
The cell wall is a common target for Antibacterial therapy. TRUE or FALSE
TRUE
Variation in peptidoglycan structure allows for differentiation b/wn Gram +ve and Gram -ve bacteria. TRUE or FALSE
TRUE
Gram +ve bacterial cell wall has a thinner peptidoglycan wall. TRUE or FALSE. If false, correct the statement
False, Gram +ve cell wall has a thicker peptidoglycan wall
What is Periplasm ?
An aqueous gel-like region b/wn 2 membranes of gram -ve bacteria
Periplasm contains enzymes associated w/nutrient acquisition and transport. TRUE or FALSE
TRUE
Periplasm contains defence enzymes used to resist antibiotics.
TRUE or FALSE
TRUE
Give an example of a defence enzyme used to resist antibiotics.
B (beta) -Lactamase
The outer membrane of Gram -ve bacteria contains PORINS. TRUE or FALSE
TRUE
What is the role of Porins
- Allows passive diffusion of molecules into periplasmic space
- Allows passage of charged molecules
Explain the process of Gram staining
1) Heat bacteria (Gram + and -) with Crystal Violet
2) Add Iodine solution
- this forms insoluble crystals
3) Decolourise with alcohol
- crystals escape from gram -ve
4) Stain w/ Safranin
- Red stain appears in gram -ve
Name the 3 types of Active transport in bacteria
1) PMF driven transport
2) ABC driven transport (ATP binding cassette)
3) Group translocation
State the 2 types of prokaryote DNA
1) Nucleoids
2) Plasmids
Bacterial ribosomes are free in cytoplasm. TRUE or FALSE
TRUE
Bacterial ribosomes are composed of 2 subunits. TRUE or FALSE
TRUE
State and describe the 2 subunits bacterial ribosomes are composed of…
1) Small 30s subunit; binds to mRNA
2) Large 50s subunit; completes 70s ribosome
Describe S.Aureus bacteria
- Gram +ve cocci
- Causes variety of infections and disease
- Particularly resistant therefore difficult to treat
Name 4 types of Gram +ve bacteria
1) S. Aureus (S=Staphylococcus)
2) C. Difficile (C=Clostrodium)
3) M. Tuberculosis (M=Mycobacterium)
4) S. Pneumoniae (S=streptococcus)
Describe S.Pneumoniae bacteria
- Gram +ve
- Causes respiratory infections
Describe C.Difficile bacteria
- Gram +ve rods
- Causes Inflammation (colitis) and Abdominal disease
- Survives in Anaerobic environment
Describe M. Tuberculosis bacteria
- Gram +ve rods
- Resides in tissues due to Hydrophobic cell wall
Name 3 types of Gram -ve bacteria
1) E.Coli
2) E.Coli 0151:H7
3) H.Pylori
Is Gram positive or negative bacteria more dangerous?
Gram Negative
Describe E.Coli bacteria
- Gram -ve
- Causes Enteric, Urinary and Nosocomal infections
Describe E.Coli 0151:H7 bacteria
- Gram -ve
- Causes Hemorrhagic diseases
- Anaerobic environment required for survival
Describe H.Pylori bacteria
- Gram -ve Spirals
- Associated w/ Chronic Superficial Gastritis
(stomach ulcers)
