Pathogen & Disease Test: Types of Pathogens Flashcards
Health
the state of complete physical, mental and social well-being
Disease
a condition whereby part or all of an organism’s normal physiological function is upset
Infectious Diseases
Contagious, Communicable
caused by an infectious agent (pathogen) and can be transmitted from one person to another
Non-Infectious Diseases
Not Contagious, Non-Communicable
are often not clearly the result of any single factor and are further categorized into major subgroups according to their principal cause
Infectious Diseases
caused by micro-organisms known as pathogens:
viruses, bacteria, fungi, protozoans, helminths, prions
Deficiency Diseases
- non-infectious
due to an inadequate diet/unbalanced diet
EX. obesity, rickets, scurvy, marasmus
Social Diseases
due to personal behaviour or living conditions (lifestyle choices). They may or may not be caused by an infectious agent
EX. obesity, STIs, lung cancer, emphysema
Mental Disorders
encompasses a range of diseases that affect a person’s thoughts, memory, emotions, and personal behaviour
EX. Alzheimer’s, schizophrenia, and depression
Degenerative Diseases
- non-infectious diseases
caused by aging and the inability of the body to carry out effective repairs and regeneration
EX. osteoarthritis, Alzheimer’s and many cancers
Inherited (Genetic) Diseases
due to defective genes that may cause the failure of a body system throughout a person’s life or the onset of a disease may occur later in life
EX. Cystic Fibrosis, multiple sclerosis, Alzheimer’s and Huntington’s disease
Etiology
Robert Koch
the study of the cause or origin of a disease
Bacteria Structure
- outer, rigid cell wall for shape and support
- cytoplasm contains ribosomes, nucleoid and plasmids
- come contain flagellum for movement
What are the 3 shapes of Bacteria?
coccus
bacillus
spirillum
What are the 3 prefix of Bacteria?
Diplo- 2 beside each other
Staphylo- many in a cluster
Strepto- a chain
Bacteria Reproduction
Asexual reproduction, known as BINARY FISSION where the cell divides into 2
- can reproduce very quickly
Helpful Bacteria:
- decompose trash
- clean up oil spills (bioremediation)
- produce medicines
- food products
- natural flora in digestive system
Harmful Bacteria:
- disease causing
- rated on 2 characteristics: Invasiveness and Toxigenicity
Invasiveness
ability to grow inside host
Toxingenicity
capacity of bacterium to produce toxins
Virulence
ability to cause disease
Gram Positive Bacteria
- the cell wall has a thick layer of peptidoglycan and NO outer lipid membrane (peptidoglycan is on the outside)
- turns purple
- produces exotoxins
Gram Negative Bacteria
- the cell wall has a thin layer of peptidoglycan and is surrounded by an outer and inner membrane
- turns red
- produces exotoxins and endotoxins
Bacterial Diseases
- pertussis
- pneumonia
- meningitis
- strep throat
- diphtheria
- tetanus
- conjunctivitis (pink eye)
Bacteria Treatment
- immune response to the foreign invader
- produce antibodies for immediate help and future protection
- antibiotics
Virus Structure
NOT CONSIDERED TO BE LIVING
- do not contain a nucleus, organelles, cell membrane, cytoplasm
- consist of either a strand of DNA or RNA
- a protein coat (capsid) surrounds the nucleic acid
What are the 3 shapes of a Virus?
helical
icosahedral
complex
Virus Reproduction
- cannot reproduce on its own
- attaches to cell or is ingested by the cell
- releases its genetic material into the host
- cell begins making viral proteins
Virus Treatment
- the host produces antibodies
- the cell infected with the virus produces “interferons” which prevent infections in neighboring cells
- antiviral medications
Viral Diseases
- influenza
- measles
- mumps
- rubella
- rhinovirus
- HIV
- rabies
- west nile
- polio
- chicken pox/ shingles
- covid-19
Lytic Cycle
results in the death of the host cell through lysis
Lysogenic Cycle
host cell is used to replicate the viral genes but does not kill the host cell outright.
The viral infection is said to be latent
In regards to the lysogenic cycle:
the viruses are said to be temperate viruses or proviruses because they do not bring death to the host cell immediately
5 Stages of the Lytic Cycle:
- Attachment
- Penetration
- Biosynthesis
- Assembly/Maturation
- Release (Lysis)
Attachment
a lytic bacteriophage virus attaches itself to a bacterial cell and enters the cell
Penetration
injects its nucleic acid into the cell by penetrating through the cell membrane,
Biosynthesis
viral nucleic acid takes over and directs the production of new virus proteins and nucleic acid. (the host cell’s DNA is degraded)
- the nucleic acid uses the cell’s ribosomes to make new virus proteins
Assembly/Maturation
the virus proteins and nucleic acid assemble into new viruses
Release (Lysis)
newly formed virus particles are released from the host cell
- able to infect other cells
- when the host cell bursts, lysis has occurred
Fungi Structure
- larger, plant-like organisms (lacks chlorophyll)
- multicellular (except yeasts)
- has organelles including a cell wall made of chitin
- genetic material is gathered in a nucleus (eukaryotic)
- branching tubes known as hyphae (a bunch = myecilium)
Fungi Reproduction
Sexually (conjugation) Asexually: 1. Budding (yeasts) 2. Fragmentation (hyphae break off) 3. Spores
Fungi Treatment
- Fungistatic Drugs: prevent further growth
- Antifungal agents
–––> CANNOT be fungicidal due to similarity between a fungal and animal cell
Fungal Diseases
as many fungal parasites obtain food, they cause disease in their host. Thus some fungi are pathogens
EX. Ringworm, candida (yeast), athletes foot
Protozoa Structure
- unicellular, heterotrophic eukaryotic (EX. amoeba and paramecium)
- do not have cell walls but have: cell membrane, cytoplasm, vacuole, and a nucleus
What are the 4 classes of Protozoa
- Sporozoa: reproduce by forming spores
- Flagellate Protozoa
- Amoeba: ability to alter shape
- Ciliate Protozoa: hair-like structures for movement and feeding
Protozoa Reproduction
Asexual: binary fission, multiple fission
Sexual
Protozoa Treatment
immune system; depends on the specific organism
Protozoan Diseases
- parastic infections
- acquired through contaminated food or water
- bites of an infected anthropod such as a mosquito
EX. amoebic dysentery, toxoplasmosis gondii, giardia lamblia, malaria, trypanosomiasis
Helminth Structure
- mutlicellular, eukaryotes with complete organ system
- they live inside their hosts
3 types of Helminths
- Nematodes: roundworms
- Trematodes: flukes or parasitic flatworms
- Cestodes: tapeworms
Helminth Reproduction
Asexual
Sexual
- usually begin life in the intestinal tract
- enzymes dissolves egg shells and release the worms that can move to organs throughout the body
Helminth Treatment
use of anti-worm drugs:
vermifuge: stun them leading to eventual death
vermicide: kill immediately
Helminth Diseases
swimmers itch
trichinella sprialis
Prion Structure
- protein particle
- mis-folded proteins
Prion Reproduction
- affect neighboring cells
- induce it to have the same mishap it has
Prion Treatment
- no treatment as of yet
- incurable and invariable fatal
Prion Diseases
- degenerative disorders of the central nervous system (CNS)
- result in brain tissue that is riddled with holes
EX. Creutxfeldt-Jakob disease, Scrapie, Bovine Spongiform Encephalaopathy, Kuru
Zoonosis
an infectious disease that is transmitted between species from animals to humans
