Communicable Diseases and Immunity Flashcards
what do bacteria not have (prokaryote specific)
Membrane bound organelles
Examples of bacterium
TB, Meningitis, Ring Rot
How does bacteria reproduce?
Binary fission
How do we stain bacterium?
gram staining
what does gram staining show?
The type of cell wall that the bacterium has.
Gram negative or gram positive.
What are the results for gram staining?
Gram negative - red
Gram positive - blue purple (like MRSA)
Why is gram staining useful?
To see the type of cell walll because the type of cell wall affects what antibiotics are used.
How does bacteria affect body cells?
Produces toxins and/or kills the cell.
What are bacteriophages?
Viruses that infect bacterium.
are viruses smaller than bacterium? by how much?
yes, by 50 times.
Name the basic structure of a virus?
some genetic material (can be RNA or DNA) surrounded by proteins
List Viruses
- HIV
- Rhinovirus
- herpes
- influenza
- tobacco mosaic virus
How do viruses reproduce?
Viral genetic information takes over “biochemistry” host cell and producing replicas.
How do viruses evolve?
By making adaptations to the host cell.
How can bacteriophages be used?
To identify and treat bacteria related diseases
What are the bits on the outside of viruses called?
spike proteins
Explain the viral reproduction process in host cells… (5 points)
- virus attatches to outside of host cell.
- virus inserts viral nucleic acid (RNA or DNA)
- viral nucleic acids replicated
- If viral nucleic acid is RNA, viral proteins will be synthesised
- lysis, toxic products
What are protists?
Eukaryotes
what are protists found as?
Single celled organisms and colonies of cells
What is special about protists?
They are parasitic and often use host vectors and sometimes through water.
Where do pathogenic fungi often live live on mammals?
Between layers of skin
Fungal projections…
hyphae
Fungi animals vs plants…
Cause more devistation in plants
In which domain do fungi belong?
Eukarya / eukaryotic
How do fungi digest their food?
extracellularly
Fungi that feed on dead and decaying matter…
saprophytes
Fungi that feed on living matter…
parasites
What can bacterial toxins do to cells? 3 points
- damage membrane
- inactivate or damage enzymes
- interfere with host cells’ genetic information.
Death distribution per year…
- 23% communicable diseases
- 68% non-communicable
- 9% injury
cause of potato blight
fungus- like protist oomycete
cause of black sigatoka
fungus
cause of ring rot
bacterium
What does TB do?
Damage and destroy lung tissue, supress immune system.
What does bacterial meningitis cause?
- infection of the meninges of the brain (protective layers on the outside of the brain)
- septicemia
What cells does HIV target?
T- helper cells
How do mosquitoes transmit malaria? 3 points
- vector
- plasmodium present in salivery gland
- transfer paritite from mosquito to human blood upon injection
What do viruses do to cells?
take over the cell metabolism
what do protoctista
take over cells and break them as a new generation emerges.
Dont take over the genetic information.
digests cell contents.
what do fungi do?
digest living cells
what do bacterium do?
toxins that damage cell membranes, deactivate enzymes or damage genetic material so host cells can not divide.
name of TB bacterium
myobacterium tuberculosis
a disease that can spread from animal to humans?
zoonotic disease
Methods of Transmission of pathogens between animals and animals (6)
- innoculation
- fomites
- droplet infection
- vectors
- ingestion
- direct contact
direct transmission
- innoculation
- ingestion
- direct contact
Innoculation
through breaks in the skin
direct contact
from skin to skin contact
ingestion
eating or drinking contaminated substances
fomites
equipment and inanimate objects
droplet infections
pathogens expelled via minute droplets of saliva and mucus
vectors- animal
disease carried from one host to another. can be an animal or water.
factors affecting animal disease
- overcrowding
- poor nutrition
- poor waste disposal
- climate change
- socioeconomic factors like lack of trained health workers
transmission between plants- direct
direct contact with an infected plant.
Transmission between plants- indirect
contaminated soil and vectors ( wind, water, animals and humans)
an example would be contaminated pollen.
factors affecting transmission in plants
- overcrowding
- poor mineral nutrition
- damp warm conditions
- planting disease susceptible crops
How do plant cells recognise attack?
- receptors in cells respond to molecules sent by pathogens or to chemicals produced when the plant wall is attacked.
How do plant cells respond to attacks
signalling molecule is released.
It switches on genes in the nucleaus that causes a cellular response.
3 cellular responses that plant cells produce when being attacked by pathogens
produces defensive chemicals
sending alarm signals to neighbouring uninfected cells
physically strengthening cell walls
how does a plant cell physically strengthen its walls?
Deposits callose between cell wall and cell membrane, in plasmodesmata and sieve plates
beta 1,3 and 1,6 linkages
lignin is also added
plants do not …
repair damaged cells
some defence molecules…
directly target pathogens
list chemical defences
- insect repellants
- antigungal compounds
- antibacterial compounds
- imsecticides
list 2 insect repellents
- citronella
- pine resin
List 2 insecticides
- caffeine
- pyrethins
list 2 antibacterial and anti fungal compounds
- phenols
- saponins
What does a plant cell deposit between the cell wall and plasma membrane and in plasmadesmata
callose
