M1: Virus Viroids Prions & Fungi Flashcards
A complete infectious particle combing these structural elements. Can be envisioned as a delivery system that surrounds a nucleic acid payload.
Virion
Infectious particles. Acellular. Not considered living organisms. DNA or RNA, never both. They are obligate intracellular parasites.
Viruses
Infectious agents that are minimally constructed of two components. ______ either RNA or DNA but not both.
Viruses. Genome
Two components of Viruses
Genome & Capsid
A protein containing structure designed to protect the genome
Capsid
Viruses in coconut
Kadang kadang
Obligate intracellular parasites of plants. Acellular. Naked RNA. No human diseases known.
Viroids
Infectious protein composed entirely of protein which cause transmissible spongiform encephalopathies. Highly resistant to inactivation. Do not elicit an inflammatory response or an antibody response.
Prions
Prions: pathogenic
Beta pleated sheet
Prions: non pathogenic
Alpha helix
Prions are infectious proteins: cellular form of the protein ______ is encoded by the host’s chromosomal DNA.
PrP
Prions are infectious proteins: is susceptible to protease and soluble in detergent
PrPc
Same AA, different protein
Conformers
Prions are infectious proteins: abnormal _________ modify folding of normal prion like proteins found in the body (code by human genes) and has high beta sheath content.
Isoform PrPsc
Present with cereberal problems
Kuru (kuria/guria)
Presenting symptoms are like dementia
Creutzfeldt Jakob Disease
Appearance of the vacuolated neurons as well as their loss of function and the lack of an immune response or inflammation
Spongiform encephalopathies
Human prion diseases
CJD, Kuru, vCJD, GSS syndrome, FFI & Sporadic Fatal Insomnia
Also known as mad cow disease
Bovine spongiform encephalopathy
Impervious to standard viral disinfection procedures. Very long incubation periods. As long as 30 years.
Animal prion disease
Animal prion diseases
Scrapie, Transmissible milk encephalopathy, BSE & chronic wasting disease
From sheep and goats
Scrapie
From mule, deer & elk
Chronic wasting disease
Transmission of prions through cut in skin, transplantation of contaminated tissues, use of contaminated medical devices and ingestion of infected tissue.
Infected tissue
Susceptible population in prion’s disease
Women & Children of Foretribe in New Guinea, Neurosurgeon, transplant and patients
Progressive neurodegenerative disease. Loss of muscle control, shivering, myoclonic jerks, loss of coordination, rapidly progressive dementia and death.
Prions
Treatment for Prions
No available
Type of nucleic acid found in the virus particle is perhaps the most fundamental and straightforward of viral properties
Viral genome
Most common forms of viral genomes found in nature
ssRNA & dsDNA
DNA viruses
Hepadna, Herpes, Adeno, Pox, Parvo, Polyoma & Papilloma “HHAPPPPy”
RNA viruses
Coronavirus, Calicivirus, Hepevirus, Picornavirus, Flavivirus, Retrovirus & Togavirus “CCHeaP FaRT”
Range in size from 20-300nm. All have protein coat (capsid). Composed of repeating capsomeres. In some, covered with lipoprotein envelope.
Viral structure
Nucleic acid + capsid
Nucleocapsid
Shape Viral symmetry
Spherical (Icosahedral) or Helical
Are enveloped
Helical viruses
Can be enveloped or naked
Icosohedral viruses
Attachment to host cell receptors
Surface proteins
Interaction between nucleocapsid and envelope
Matrix protein
Evasion of host defenses
Antigenic (serotypic) variants
Lipid containing membrane surrounding the nucleocapsid.
Viral envelope
Acquired as the virus exits from the cell in a process called
Budding
All enveloped viruses acquire their enveloped viruses from plasma membrane except
Herpesvirus
Herpesvirus are from
Nuclear membrane
Are less stable and more easily inactivated
Enveloped viruses
Naked Viruses
Calici, Picorna, Reo, Parvo, Adeno, Papilloma & Polyoma “CPR PAPP”
All DNA viruses have double stranded DNA except
Parvovirus
All DNA viruses have linear DNA except
Papilloma, Polyoma & Hepadna
All DNA viruses are icosahedral except
Poxvirus