Module 05: Acellular and Prokaryotic Microbes Flashcards
What are some examples of cellular microbes?
(1) Bacteria
(2) Archaea
(3) Protozoa
(4) Algae
(5) Fungi
What are some examples of non cellular microbes?
(1) Virus
(2) Viroid
(3) Prions
What are some examples of prokaryotic microbes?
(1) Bacteria
(2) Archaea
What are some examples of eukaryotic microbes?
(1) Fungi
(2) Protista
(3) Algae
Viruses viroid and prions are often referred to as what?
Acellular microbes or infectious agents (particles)
These are known as complete virus particles.
Virions
What are the size of viruses?
They range from 10 to 300 nanometers in diameter.
These are known to infect human animals plants fungi protozoa algae and other bacterial cells.
Viruses
These are viruses delineated to cause specific types of cancer.
Oncogenic or oncoviruses
What composes a typical virion?
(1) Genome of either RNA or DNA
(2) Capsid
(3) Capsomeres
This is known as the protein coat surrounding a typical virion.
Capsid
This is known as the protein units constituting a typical virion.
Capsomeres
These viruses have an outer envelope composed of lipids and polysaccharides
Envelope viruses
What are the five (5) properties that distinguish viruses from living cells?
(1) They possess either DNA or RNA, whereas living cells possess both.
(2) They are unable to replicate on their own.
(3) Unlike cells, they do not divide by binary fission, mitosis, or meiosis.
(4) They lack the genes and enzymes necessary for energy production.
(5) They depend on the ribosomes, enzymes, and metabolites of the host cell for protein and nucleic acid production.
What are the classifications under RNA viruses?
(1) Enveloped
(2) Non enveloped
What are the classifications under non enveloped RNA viruses?
(1) Single stranded positive sense
(2) Double stranded
What are some examples of non enveloped Single stranded positive sense - rRNA?
(1) Astroviruses
(2) Caliciviruses
(3) Picornaviruses
What are some examples of non enveloped double stranded - rRNA?
(1) Retroviruses
(2) Rotaviruses
What are the classifications under enveloped rRNA viruses?
(1) Single stranded positive sense
(2) Single stranded negative sense
(3) Retrovirus
What are some examples under single stranded positive sense enveloped rRNA viruses?
(1) Toga viruses
(2) Flaviviruses
(3) Corona viruses
What are the classifications under single stranded negative sense enveloped rRNA viruses?
(1) Linear
(2) Segmented
What are some examples under linear single stranded negative sense enveloped rRNA viruses?
(1) Rhabdoviruses
(2) Paramyxoviruses
What are some examples under segmented single stranded negative sense enveloped rRNA viruses?
(1) Arenaviruses
(2) Bunya viruses
(3) Orthomyxoviruses
What are some examples under retroviruses enveloped rRNA viruses?
(1) Lentiviruses
(2) Oncoviruses
What are the classifications under DNA non enveloped viruses?
(1) Single stranded linear
(2) Double stranded linear
(3) Double stranded circular
What are the some examples under single stranded linear in DNA non enveloped viruses?
Parvoviruses
What are the some examples under double stranded linear in DNA non enveloped viruses?
Adenovirus
What are the some examples under double stranded circular in DNA non enveloped viruses?
(1) Papillomaviruses
(2) Polymaviruses
What are the classifications under DNA enveloped viruses?
(1) Double stranded linear
(2) Double stranded circular
What are the some examples under double stranded linear in DNA enveloped viruses?
(1) Herpes viruses
(2) Pox viruses
What are the some examples under double stranded circular in DNA enveloped viruses?
Hepa Viruses
What are the steps of becoming an enveloped virus?
(1) Virus specific glycoproteins are synthesized and transported to the host cell membrane
(2) The cytoplasmic domains of the membrane proteins bind to the nucleocapsids
(3) The nucleocapsid is enveloped by the host cell membrane
(4) The host cell membrane provided the viral envelope through budding
(5) The enveloped virion is released from the host cell
Viruses are classified based on what?
(1) Type of genetic material (either DNA or RNA)
(2) Shape and size of capsid
(3) Number of capsomeres
(4) Presence or absence of an envelope
(5) Type of host it infects
(6) Disease it produces
(7) Target cell(s)
(8) Immunologic/antigenic properties
What are the four (4) categories of viruses based on the type of nucleic acid that they possess?
(1) Double-stranded DNA viruses
(2) Single-stranded RNA viruses
(3) Single-stranded DNA viruses
(4) Double-stranded RNA viruses
What are the most viral genomes?
Most viral genomes are circular molecules, but some are linear.
What are the steps of multiplication of animal viruses?
(1) Attachment
(2) Penetration
(3) Uncoating
(4) Biosynthesis
(5) Assembly
Animal viruses escape from their host cells either by ___________.
lysis of the cell or by budding.
Viruses that escape by budding become ___________.
enveloped viruses.
Explain the penetration of a host cell by a nonenveloped virus via endocytosis.
(1) Binding of a virus
(2) Invagination of the membrane
(3) Formation of an endocytotic vesicle
(4) Release of virion in the cytoplasm
Explain the penetration of a host cell by an enveloped virus.
(1) Binding of the virus to a host cell membrane receptor
(2) Fusion of viral envelope with the host membrane
(3) Nucleocapsid enters the cell
Viral infections in which the virus is able to hide from a host’s immune system _____________
By entering cells and remaining dormant (Latent)
Examples of Latent virus infections.
Once acquired, herpes virus infections (e.g., those that cause cold sores, genital herpes, and chickenpox/shingles) never completely go away; for example, chickenpox may be followed, years later, by shingles—both are the result of the same virus.
These viruses cause cancer.
Oncogenic viruses or oncoviruses
What are some examples of Oncogenic viruses or oncoviruses?
(1) Epstein–Barr virus,
(2) Human papillomaviruses, and
(3) Human T-lymphotrophic virus
type 1 (HTLV-1)
This virus causes acquired immunodeficiency syndrome (AIDS).
Human immunodeficiency virus (HIV)
How do you characterized Human immunodeficiency virus (HIV)?
It is an enveloped, single-stranded RNA virus
What are the target cells of HIV?
The primary targets for HIV are CD4+ cells—those having CD4 receptors on their surface.
These are drugs that are used to treat viral infections.
Antiviral drugs (Antibiotics are not effective against viral infections)
These agents interfere with virus-specific enzymes and virus production by disrupting critical phases in viral multiplication or inhibiting synthesis of viral DNA, RNA, or proteins
Antiviral drugs
These are viruses that infect bacteria.
Bacteriophages or simply phages
What are the two categories of bacteriophages?
(1) Virulent bacteriophages
(2) Temperate bacteriophages
They are always the cause to what is known as the lytic cycle, which ends with the destruction of the bacterial cell.
Virulent bacteriophages
What is the five (5) steps of the lytic cycle?
(1) attachment,
(2) penetration,
(3) biosynthesis,
(4) assembly, and
(5) release
Explain the lytic cycle
(1) Attachment of the phage to cell surface receptor
(2) Injection of the phage DNA into the cell
(3) Synthesis of phage DNA and phage proteins
(4) Assembly of new phage particles
(5) Lysis of the cell and release of progeny phage