Zusammenfassung der Ressource
Cholera
- Prokaryotic
cells
- 'Before nucleus'
- No nucleus or nucleolus
- Only a
diffuse area
of nuclear
material
- Circular strands of DNA
and a plasmid but no
chromosomes
- No membrane-bound organelles
- Smaller 70S ribosomes
- Cell wall made of peptidoglycan
- Bacterial cell
- Cell wall
- Protects
against
mechanical
damage
- Excludes
certain
substances
- Made of
peptidoglycan
- Capsule
- Slime layers that
protects
bacterium
- Sticks cells together
- Cell-surface membrane
- Differentially
permeable
membrane
- Flagellum
- Rigid,
corkscrew
shape
- Movement
- Circular DNA
- Genetic
information
for replication
- Plasmid
- Genes to aid
survival
(antibacterial
resistance)
- Vibrio cholerae
- Transmitted through
water ingested and
contaminated with
faecal matter
- Most killed in stomach acid
- Produces a toxin
- Causes loss of microvilli
- Mechanism of infection
- 1. Bacterium
enters the small
intestine and
flagellum propels
itself into mucus
- 2. Produces a toxin made up of two
parts
- 3. One part binds to
specific glycoprotein
receptors of epithelial
cells
- 4. The other toxic part
enters the cells and causes
chloride channel ions to
open
- 5. Chloride ions flow into lumen
of the small intestine
- 6. This raises the cells water
potential and lowers the lumen's
water potential
- 7. Ions move into the epithelial cells from
the surrounding tissues and blood due to
conc. gradient and loss of chloride ions
- 8. Water moves by osmosis
from the cells and other
tissues into the lumen
- Symptoms
- Diarrhoea
- Dehydration
- Some show no symptoms
- Treatment
- Oral rehydration threapy
- Makes use of alternative
carrier proteins in epithelial
cells
- Stimulates sodium ion uptake
- Drinking water is ineffective as
intestine isn't absorbing water
- Water
- Rehydrate cells
- Sodium
- Make optimum use of
sodium-glucose channel proteins
- Glucose
- Energy and sodium ion uptake
- Potassium
- Stimulate appetite
- Other electrolytes
- Prevent imblanace