virsues

Question 1

What are the two different multiplication cycle bacteriophage reproduce in?

Answer 1

1. Lytic Cycle- bacteriophage immediately uses the host cell, making more bacteriophage & destroying the host cell in the process (More aggressive way
2. Lysogenic Cycle- Bacteriophage enters a resting phase where its genetic material is pushed into the bacterium of[ the cell where the cell reproduces while copying the bacteriophage DNA with it

Question 2

Steps of The Lysogenic Cycle

Answer 2

1. Attachment- Proteins on the surface of the virus attach to the receptors on the surface of the host cells
2. Penetration- The genetic material of the virus(DNA) enters the host cell
3. Recombination- The bacteriophage DNA is inserted into the bacteria DNA
4. Replication- The bacterial cell multiplies, copying the viral DNA along with its own DNA

Question 3

When a virus enters the cell either by fusion or receptor-mediated endocytosis, the _____ ______ inside the cell has to free its DNA from the capsid before it can replicate itself (Have to take its coat off)

Answer 3

When a virus enters the cell either by fusion or receptor-mediated endocytosis, the viral capsid inside the cell has to free its DNA from the capsid before it can replicate itself (Have to take its coat off)

Question 4

Viruses that attack Prokarytoic Cells go through what cyle?

Answer 4

Lytic Cycle

Question 5

Single- Stranded RNA Viruses Divided into what two groups?

Answer 5

1. Negative - Sense Single -Stranded RNA Viruses- Insert their single- stranded RNA molecules into the cytoplasm of the cell (Ex. Flu & Measles)
2. Positive - Sense Single- Stranded RNA molecule Viruses- Insert its single- stranded RNA molecule into the cytoplasm of the cell where it is read directly for synthesis of the viral protein (Ex. Mosaic viruses that attack crop plants)

Question 6

Steps for the lytic cycle

Answer 6

1. Attachment- Protein on the surface of the virus attach to the receptors on the surface of the host cell
2. Penetration- The genetic material(DNA) of the virus enters the host cell
3. Biosynthesis- the virus uses building blocks from the host cell such as nucleotides & amino acids to make viral proteins & nucleic acids (ATP from the host cell supplies the energy the virus needs to reproduce)
4. Maturation- The parts of viral particles assemble into new bacteriophage
5. Release- The new bacteriophage exit the host cell, lysing the cell as it leaves

Question 7

Since each virus can only infect cells that match with their proteins, each virus has a specific range of host it can infect which are what?

Answer 7

1. Host Range- the type of cells a particular virus can infect
2. Broad Host Range- viruses that can match to many cells
3. Narrow Host Range- Viruses that can only attach themselves to a few types of cells

Question 8

Budding

Answer 8

Release of a immature virus as the viral proteins push out the host cell wrapping itself in a new envelope, where the enzyme protease begins cutting the viral protein

Question 9

Genetic Variations in viruses are caused by what?

Answer 9

Since there are many ways that the genetic material of the virus can enter the cell, it creates many different enzymes to copy its genetic material, but those viral enzymes make more mistake than host enzymes which causes genetic variations in viruses making it harder for viruses to defeat the immune system or antiviral drugs

Question 10

Capsomere

Answer 10

each individual protein that makes up the capsid

Question 11

Spikes

Answer 11

proteins that stick out of the envelope or off the surface of the Capsid(Ex. Polyhedral viruses & Spherical(Envelope) viruses )

Question 12

How do viruses leave the cell?

Answer 12

Viruses that contain an envelope leaves the cell by Budding- the capsid of the virus pushes up against the plasma membrane, plasma membrane wraps around the virus as it leaves the cell

Question 13

What are the Principles used by viruses when attacking Eukaryotic cells?

Answer 13

1. Latent instead of Lysogenic(Latent Viruses)- Eukaryotic viruses that have a dormant period(resting phase) within the cell (Ex. Herpes)
2. Provirus instead of prophage(Provirus)- a virus that is dormant inside the Eukaryotic cell
3. Acute disease instead of Lytic Cycle(Acute Illness)- viruses that attack human cells quickly, reproduce rapidly & cause a rapid but short illness (Ex. Common Cold)

Question 14

Viruses attack Eukaryotic cells by first attaching its ___________ to the ________ of the host cell, where after binding with the host it crosses the plasma membrane of the host

Answer 14

Viruses attack Eukaryotic cells by first attaching its viral proteins to the receptors of the host cell, where after binding with the host it crosses the plasma membrane of the host

Question 15

How do Viruses attack bacteria?

Answer 15

• Bacteriophage- viruses that attack bacteria cells (Phage- means eats so “bacteria eaters”)
• Bacteriophage attach themselves to bacteria cells, enter the cell & hijack the cell using the materials & structures in the cell to make more bacteriophage

Question 16

Multiplication cycle of viruses that attack __________ are more _________ than attacks on Prokaryotic cells

Answer 16

Multiplication cycle of viruses that attack Eukaryotic cells are more complex than attacks on Prokaryotic cells

Question 17

What are the Multiple Ways to Copy a Virus?

Answer 17

• For viruses to reproduce it needs its DNA copied
• In Eukaryotic cells, reproduction of the nucleic acid (DNA & RNA) occurs in the nucleus while synthesis of proteins occurs in the cytoplasm (So a virus would have to visit both areas to complete the multiplication cycle)

Question 18

What are Viruses?

Answer 18

Are microscopic particles of nucleic acid (DNA & RNA) & protein that attack cells & turn them into factories for producing more viruses (Soome have the ability to stay dorimant(resting) inside a host cell for a period of time)

Question 19

Prophage

Answer 19

the bacteriophage that injects its DNA into the bacteria cell

Question 20

What are the types of Shapes Viruses have

Answer 20

1. Helical Shape- have a capsid that forms a twisting helix around the nucleic acid(DNA & RNA) (Ex. Helical viruses like Tobacco mosaic virus)
2. Polyhedral Shape- have a regular geometric shape where it looks like a hexagon (Icosahedrons- most complex viruses with 20 sides)
3. Complex Shape- have a separate parts which are its head, tail, plate, tail fiber, tail, and collar

Question 21

What is the difference between cells & viruses?

Answer 21

Difference between cells & viruses is that cells contain both DNA & RNA where viruses have either RNA or DNA(Never both but Single- Stranded DNA & Double- Stranded RNA are most common in viruses but not cells)

Question 22

Antibiotics

Answer 22

are chemicals that poison bacteria based on the bacteria structures but does not harm human cells (Only work on bacteria cant work on viruses because viruses don’t have the same structure as bacteria)

Question 23

Why can a single- stranded RNA virus be called a ngetaitve- sense virus?

Answer 23

Called negative - sense viruses because their RNA molecules cant be read directly to create proteins, first their negative - sense RNA molecules must be read to make a complementary (Mirror image) RNA molecule where that mirror image RNA molecule create more viral protein

Question 24

Double- Stranded DNA Viruses

Answer 24

Inserts its genetic material into the host nucleus where its DNA is copied as the host copies its own DNA to prepare to divide (Ex. Smallpox)

Question 25

How do How Viruses Enter The Cell?

Answer 25

* Viruses attach to cells by having the viral protein bind to the receptors on the host cell, where to be able to bind with the cells have to match the receptors on the host cell (Ex. Lock & Key) * The viral proteins have to be the right shape to attach with the host cell receptors, where it would either force itself inside by digging a hole through cell wall, fuse its envelope with the plasma membranes or trick the cell into bringing it inside

Question 26

Simple viruses have just two components which are what?

Answer 26

1. _Nucleic acid core_- may be DNA or RNA that contains the instructions for taking over the cell & making more virions- viral particles 2. It’s also surrounded by a _Capsid_- a protective protein coat

Question 27

Reverse Transcription

Answer 27

* The enzymes reverse transcriptase convert the single - stranded viral DNA molecules into double - Stranded DNA

Question 28

Vaccines

Answer 28

a little piece of the bacteria or virus injected into the body to help educate & prepare the immune for the bacteria or virus before it comes

Question 29

What are the 4 types of viruses?

Answer 29

1. Helical RNA Virus 2. Polyhedral (Icosahedral) DNA Virus 3. Enveloped RNA virus 4. Complex DNA Virus

Question 30

Uncoating

Answer 30

process of removing the capsid (The enzymes of the host breaks down the viral capsid causing it to release its DNA)

Question 31

What is a Temperate Bacteriophage?

Answer 31

Can switch between lytic & lysogenic cycles (Some bacteriophage can only go through one or the other)

Question 32

Multiplication Cycle of the Virus(Also called the replication cycle)

Answer 32

series of events that occurs as the virus hijack the cells

Question 33

All viruses have at least a ______ & __________ where it consist of being one of the four:

Answer 33

All viruses have at least a Capsid & a Nucleuic acid(DNA or RNA) core where it consist of being one of the four: 1. Double- Stranded DNA 2. Single- Stranded DNA 3. Double - Stranded RNA 4. Single - Stranded RNA

Question 34

Retro Viruses

Answer 34

Contains a single - stranded RNA for their genetic material where once the RNA enters the cytoplasm of the cell, the virus uses _Reverse Transcriptase(Unique enzyme)_ - to make DNA copy the RNA * The double stranded DNA enters the nucleus, where it inserts into the host DNA by recombination (Ex. HIV, it follows the same process where it can be latent or can * During the active replication the RNA molecules move back out into the cytoplasm where it used to make viral proteins

Question 35

Envelope

Answer 35

is the outer membrane layer where it protects the virus from the cells it has attacked while its leaving the cell(Also contain viral proteins)

Question 36

Double - Stranded RNA Viruses

Answer 36

Take its RNA molecules into the cytoplasm of the cell, where the double- stranded molecules are used to make the single- stranded RNA molecules that are needed for reproduction of viral proteins (Ex. Viruses that attack important crops) * It's multiplication cycle occurs in the cytoplasm of the cell

Question 37

After an a virus containing an envelope attacks the host cell its enters what two possible ways?

Answer 37

1. _Fusion_- occurs when the envelope of the virus melts into the plasma membrane where its fuses into one, where once its fused the viral capsid is inside the cell 2. _Receptor mediated endocytosis_- occurs when the virus binds with the host cell, where the cell reaches out and wraps around to form a vesicle to bring the virus inside the cell with( Envelope & All)