Microbiology Lecture Practical 1 Part 4; Chap 1, 4, 5, & 6

Naked viruses are released by

lysis

Together, nucleic acid and capsid are referred to as _____.

nucleocapsid

Viruses that consist of only a nucleocapsid are considered

Naked viruses

What are the two structures of viruses?

Naked viruses and enveloped viruses.

The entrance of the virus inside the host cell

Penetration

Refers to being able to take multiple shapes.

Pleiomorphic

_____ are enzymes that are involved in DNA and RNA protein synthesis.

Polymerase

The latent or inactive stage of viral DNA when incorporated into the bacterial chromosome is called

Prophage

A viral disease that lasts a specific amount of time not long maybe a few days or weeks and usually resolves by itself. It usually caused by naked viruses but can be enveloped virus too.

Acute infection

What are the 3 viral disease patterns?

Acute infection, persistent infection, and transformation

protruding molecules, called ______ are essential for the attachment of viruses to the next host cell.

Spikes or peplomers

The entry of viral nucleic acid stops host cell DNA replication and protein synthesis and viral DNA and protein is replicated instead

Synthesis

Under the control of viral genes, the cell makes new viral components: RNA molecules, capsomers, and spikes

Synthesis: replication and protein production

This type of persistent infection has the virus enter the host cell and permanently alters genetic material

Transformation

Having an affinity for a tissue or cell type is called

Tropism

T or F? The envelope is a modified section of the host cell membrane.

True

T or F? The function of the capsid/ envelope of a virus is to protect the genetic material from degradation, introduce genetic material into the host cell, and stimulate the immune system for antibody production.

True

The general steps in a viral multiplication cycle are a. Adsorption, penetration, synthesis, assembly and release b. Endocytosis, replication, assembly and budding c. Adsorption, duplication, assembly and lysis d. Endocytosis, penetration, replication, maturation and exocytosis

a. Adsorption, penetration, synthesis, assembly and release

A prophage is a/an ______ stage in the cycle of ________. a. Latent, bacterial viruses b. Infective, RNA viruses c. Early, poxviruses d. Late, enveloped viruses

a. Latent, bacterial viruses

Bacteriophages attaches to host cell surface

adsorption

The multiplication cycle of a bacteriophage includes

adsorption, penetration, synthesis, assembly, and release

Viral multiplication consists of multiple steps

adsorption, penetration, uncoating, synthesis, assembly, and release

All component assembled into finished viruses

assembly

In general, RNA viruses multiple in the cell _______ and DNA viruses multiple in the cell _______. a. Nucleus, cytoplasm b. Cytoplasm, nucleus c. Vesicles, ribosomes d. Endoplasmic reticulum, nucleolus

b. Cytoplasm, nucleus

The envelope of an animal virus is derived from the ________ of its host cell. a. Cell wall b. Membrane c. Glycocalyx d. Receptors

b. Membrane

Enveloped viruses carry surface receptors called a. Buds b. Spikes c. Fibers d. Sheaths

b. Spikes

The 2 types of persistent infections are

chronic and latent

This type of persistent infection has the virus actively multiplying and last years

chronic infection

Viruses are known to infect a. Plants b. Bacteria c. Fungi d. All organism

d. All organism

The capsid is composed of protein subunits called a. Spikes b. Protomers c. Virions d. Capsomers

d. Capsomers

Which of these is NOT a general pattern of virus morphology? a. Enveloped, helical b. Naked, icosahedral c. Enveloped, icosahedral d. Complex, helical

d. Complex, helical

The nucleic acid of a virus is a. DNA only b. RNA only c. Both DNA and RNA d. Either DNA or RNA

d. Either DNA or RNA

A virus is a tiny infectious a. Cell b. Living thing c. Particle d. Nucleic acid

d. Nucleic acid

The nucleic acid of animal viruses enters the host cell through a. Injection b. Fusion c. Endocytosis d. b and c

d. b and c

Penetration via _____ cell engulfing the virus and once inside virus is enclosed.

endocytosis

Persistent infections are caused by

enveloped viruses

Viruses that possess additional covering external to the capsid is called

enveloped viruses

Penetration can be via _____, viral envelope fuses directly with the host cell membrane.

fusion

The exposure to certain environmental causes prophage to progress into viral replication cycle is called

induction

The virus attaches to its host cell by specific binding of its spikes to cell receptors.

Adsorption

The host cell accumulates damage after using its energy on the virus and dies is called

Cytopathic effects

T or F? The genetic material can be both RNA and DNA.

False. The nucleic acid of the viral genome is either DNA or RNA but not both.

most common type of viral infection of GI caused by Rotavirus.

Gastroenteritis

An example of a chronic infection

HIV, Hepatitis B

What are the 2 different arrangement of capsids?

Helical and Icosahedral

Rod-shaped capsomers that bind together to form a series of hollow disc resembling a bracelet is called

Helical capsid

_____ receptors that allow the virus to bind to the respiratory epithelium.

Hemagglutinin

An example of latent state infection is

Herpes simplex that causes cold sore and genital herpes

An example of transformation infection is

Human papilloma virus

The capsids are arranged in a three-dimensional, symmetrical polygon with 20 sides and 12 evenly-spaced corners are called _____. I can be naked or enveloped.

Icosahedral capsid

An example of acute infection by enveloped virus is

Influenza (flu)

The nucleic acid is injected through the bacterial cell wall and membrane and empty capsid remains

penetration

Bacteriophages have a _____ capsid head, a collar, body of sheath, helical tail with pins, and tail fibers that allow the phage to land on the bacteria.

polyhedral

Some examples of viral enzymes are

polymerase and reverse transcriptase

The host cell is packed with viruses and viral enzymes weaken the host cell wall causing lysis and mature virions are

released

The fusion of multiple host cell into a large cell containing multiple nuclei is called

syncytia

This viral infection of the upper respiratory affects

throat, larynx, trachea, and larger bronchi

Some regular membrane proteins are replaced with _____ during the virus assembly process.

viral proteins

What are mature, released viruses that can infect another cell.?

Virions

This crop pathogen is a naked strand of RNA and is extremely small around 1/10 size of a virus.

Viroids

A virus that affects bacteria is called

Bacteriophages

Huge viruses with 2500 genes are called

Pandoraviruses

This type of persistent infection has the virus inactive most of the time

Latent state

The acquisition of phage genes by bacteria cause its phenotype to change is called

Lysogenic conversion

The host bacterial chromosome carries the bacteriophage viral DNA is called

Lysogeny

_____ is considered a less deadly form of infection as it allows the virus to spread without killing its host.

Lysogeny

List viruses from largest to smallest.

Megavirus, Poxvirus, Herpes simplex, Rabies, HIV, Influenza, Adenovirus, T2 bacteriophage, Poliomyelitis, Yellow fever, Hemoglobin molecule.

_____ allows virus to penetrate through the mucus to access the epithelial cells.

Neuraminidase

_____ is the common cause of gastroenteritis in contained settings like cruise ships and schools.

Norovirus

_____ refers to synthesizing DNA from RNA enzymes.

Reverse transcriptase

An example of acute infection by a naked virus is

Rhinovirus

This virus from the family Coronaviridae is a + strand RNA virus, has an enveloped helical capsid and is pleiomorphic. It binds to the respiratory cells and has 4 important proteins: S protein, M protein, E protein, and N protein.

Sars-CoV2

depend on other viruses for repication

Satellite viruses

naked and enveloped viruses are released via lysis or budding.

Viral release

release if viral capsid/ nucleic acid into the cytoplasm.

Uncoating

In this step of viral multiplication, the capsid is laid down and genetic material is inserted in the capsid. In enveloped viruses, glycoprotein spikes are inserted into the host cell membrane.

Viral assembly

_____ refers to proteins that speed up the rate of reaction.

Viral enzymes

_____ are obligate intracellular parasites of bacteria, protists, fungi, plants, and animals.

Viruses

In lower respiratory infections, the virus enters the

bronchioles and lungs

Enveloped viruses are released by

budding or exocytosis

Viruses that persist in the cell and cause recurrent disease are considered a. Oncogenic b. Cytopathic c. Latent d. Resistant

c. Latent

What do you call the protein coat of a virus that surrounds the nucleic acid?

capsid