Infectious agents Flashcards
List the main characteristics of fungi
Eukaryote cells
Very diverse, include yeasts (unicellular) and moulds (multicellular)
Decompose dead plant and animal matter into absorbable nutrients for themselves and other organisms
Classified by how they reproduce. Different fungi reproduce by different ways.
Reproduce by budding, hyphen extension, and formation of spores
List distinguishing characteristics of protozoa
Eukaryote cells therefore have a nucleus
Most are unicellular
Protozoa ingest food and then digest within the cell
Classified by the way they move/mode of locomotion
Usually found in soil and water, some can live on or in humans and animals
Parasitic protozoa (parasites) break down and absorb nutrients from the body of the host that they live on.
How does the flagella allow protozoa to move
Whip like tail that propels cell through watery environments
Cilia
Hair like appendages which move in synchronised waves to propel cell along
Pseudopodia
“false foot” large cells surrounded by a membrane and lacks shape. Moves by extending cell membrane then allowing cytoplasm to flow into the extension.
List three protozoan diseases that occur in humans
Plasmodium, causes malaria
Giardia intestinal causes giardiasis
Toxoplasma gondi causes Toxoplasmosis
What is nucleic acid on a virus
single type of nucleic acid, either RNA or DNA
What is a capsomere on a virus
Protein coat or ‘capsid’ surrounding the nucleic acid
what is an envelope on a virus cell
In some viruses, a membrane-like envelope surrounds the capsid
Spikes
Protein spikes on envelope aid in attachment and entry to host cells
what makes viruses different to other cells?
Do not have a cell structure
Requires a host cell in order to replicate
Obligate intracellular parasites
What are the 5 steps to virus replication?
Attach (to particular host cell)
Enter and uncoat (capsid removal by host enzymes)
Replicate (viral nucleic acid and synthesis of viral proteins)
Assembly (of new complete virus particles)
Release (of virus particles from host cell - which may burst)
List some common viral infections
influenza, mumps, norovirus, rotavirus, Hepatitis, Measles, Polio
State which of these are eukaryote, prokaryote and acellular :
Bacteria
Fungi
Protozoa
Viruses
Bacteria = prokaryote
Fungi = eukaryote
Protozoa = eukaryote
Viruses = acellular
List the chain of infection
Infectious agent
reservoir
portal of exit
mode of transmission
portal of entry
susceptible host
