Introduction to microorganisms Flashcards
List the six stages of the chain of infection.
Infectious agent, Reservoir, Portal of exit, Mode of transmission, Portal of entry, Susceptible host
What are 3 standard precautions or safety measures undertaken in a clinical setting.
Hand hygiene, PPE (Personal protective equipment), disposal of sharps, waste management, routine cleaning.
The study of organisms too small to be seen with the naked eye
Microorganisms
Example of Prokaryote
Bacteria
Example of Eukaryote
Fungi, Protozoa, yeast and mould
Example of a non cellular microorganism
Virus
State 3 difference between prokaryote and eukaryote microorganisms,.
Pro - Unicellular Eu - Multicellular
Pro - NO Eu - membrane-bound organelles
Pro - DNA not in a membrane Eu - DNA in membrane
The first word in the name is the _____ with the first letter always written in capitals
Genus
The second is the _____ which is not written as a capital.
species
When writing the both words of a scientific name of a microorganism what do you do?
Underline it
Escherichia can also be written as
E. Coli
What is beneficial bacteria?
Assist with various body processes and/or Crowd out and prevent infection by harmful bacteria
What is opportunistic bacteria?
Microflora that is potentially harmful and can cause disease under certain conditions
What is Resident microflora ?
Species that are always in or on the human body found on skin and conjunctiva
Describe structure and function of the capsule of bacteria.
outer surface of a bacteria cell, aids in attachment to surfaces.
Describe structure and function of the cell wall of bacteria.
maintains the shape of the cell, offers protection from environmental factors
Describe structure and function of the cell membrane of bacteria.
phospholipid bilayer which is selectively permeable, allowing some particles to pass through.
Describe structure and function of the cytoplasm of bacteria.
substance inside of a cell membrane, 80% water acting as a medium for many metabolic reactions in the cell.
Describe structure and function of the ribosomes of bacteria.
found in random grouping , functions as the site of protein synthesis.
Describe structure and function of the chromosome/nucleiod of bacteria
consists of a single, long molecule of DNA and contains the genetic information for metabolism and reproduction.
Describe structure and function of the plasmid of bacteria
small, circular, double stranded piece of DNA, doesn’t carry genes for normal function. carries genes for antibiotic resistance.
Describe structure and function of the pill/fimbriae of bacteria
this, hair like structure on surface of many negative cells. helps cell attach to surfaces and can transfer genetic information.
Describe structure and function of the flagellum of bacteria
some bacteria have these, they propel the cell along. long thread like attachment.
Describe structure and function of the endospore of bacteria
formed by certain bacteria in unfavourable conditions and are resistant to heating and drying.
What are the main characteristics of Fungi?
found everywhere, can only live on organic material in water and soils, some are parasitic/harmful/beneficial, fungi grow where bacteria dont thrive,
What are the main characteristics of mould?
they grow on substances with low moisture, able to grow in high sugar and salt concentrations, many prefer acidic conditions (fruit) and they can tolerate cold conditions.
What are the main characteristics of yeasts?
yeasts are found in soil and water and the surface of fruit and vegetables. yeasts can be used for fermentation to produce wine and beer.
Describe and state an example of superficial fungal infection.
Superficial infections occur on the outer parts of the body e.g. skin, hair, nails
Examples: Tinea pedis (athlete’s foot), Tinea corporis (ringworm)
Describe and state an example of systemic fungal infection.
Affect tissues and organs deep within the body e.g. lungs
Example: Aspergillosis
Describe and state an example of opportunist fungal infection.
Fungal infections caused by fungi that are normally harmless. Example: Vaginal or oral thrush
Name the main characteristic of protozoa and how they move
Eukaryote cells, Most are unicellular free-living microorganisms, They are usually found in soil or water, protozoa ingest food and digest within the cell. They move by locomotion.
Give an example of protozoa in the body
Plasmodium spp. causes Malaria, Giardia intestinalis causes Giardiasis, Toxoplasma gondii which causes Toxoplasmosis
Describe the structure of viruses
- Single type of nucleic acid - either RNA or DNA
- Protein coat or ‘capsid’ surrounds the nucleic acid
- In some viruses, a membrane-like envelope surrounds the capsid
- Protein spikes on envelope aid in attachment and entry to host cells
list characteristics of viruses that distinguish from cellular organisms.
- Viruses do not have a cell structure i.e. they are acellular
- Viruses require a host cell in order to replicate
- Most viruses can only infect specific cells of one particular species
What are the Steps in Virus Replication
- Attachment to appropriate host cell
- Entry and uncoating (capsid removal by host enzymes)
- Replication of viral nucleic acid and synthesis of viral proteins
- Assembly of new complete virus particles
Release of virus particles from host cell (which may burst
Give 3 examples of viral infections.
influenza, mumps, rubella ,measles, rubella
Giva an example of Latent Viral Infections.
Herpes
