Viral Cell Biology

Front 1

What 2 things is a virus composed of?

Back 1

1.) DNA or RNA

2.) A protein coat

Front 2

What are viruses that infect fungi called?

Back 2

Mycophages

Front 3

What is a bacteriophage?

Back 3

A virus that infects bacteria

Front 4

Why are viruses not cells?

Back 4

They do not have any metabolic activity

Front 5

What is a capsid?

Back 5

The protein coat that surrounds the DNA/RNA of a virus

Front 6

What is a capsid composed of and how is it formed?

Back 6

Capsomers (proteins) that self-assemble

Front 7

What is the function of a capsid?

Back 7

Protects the RNA/DNA of a virus

Front 8

What does the capsid determine for the virus?

Back 8

Its shape

Front 9

What are the 3 types of virus?

Back 9

1.) Naked

2.) Enveloped

3.) Complex

Front 10

What classifies a naked virus?

Back 10

1.) Capsid

2.) Nucleic acid (DNA/RNA)

3.) Enzymes

Front 11

Name an example of a naked virus

Back 11

Adenovirus - causes cold, pneumonia, bronchitis etc.

Front 12

What classifies an enveloped virus?

Back 12

1.) Capsid

2.) Nucleic acid (RNA/DNA)

3.) Enzymes

4.) Biomembrane surrounding the capsid

5.) Envelope proteins on the biomembrane

Front 13

Where are the lipids that form the biomembrane of an enveloped virus from?

Back 13

The host cell

Front 14

Where are the envelope proteins that are found on the biomembrane of an enveloped virus from?

Back 14

The virus

Front 15

Name an example of an enveloped virus

Back 15

HIV - causes AIDS

Front 16

What classifies a complex virus?

Back 16

1.) Capsid

2.) Nucleic acid (RNA/DNA)

3.) Enzymes

4.) Complex protein tail

Front 17

Name an example of a complex virus

Back 17

T4 bacteriophage

Front 18

Name some examples of enzymes that are found in viruses

Back 18

1.) Lysozyme

2.) Reverse transcriptase

3.) Protease

Front 19

Name the 3 distinct ways in which viruses enter the cell

Back 19

1.) Endocytosis

2.) Membrane fusion

3.) Injection

Front 20

What happens during endocytosis?

Back 20

1.) Virus triggers clathrin-mediate endocytosis

"Trojan Horse" method

Front 21

What happens during membrane fusion?

Back 21

Enveloped virus particules bind to receptions in the plasma membrane of the host cell

This forces membrane fusion

Front 22

What is different about a bacteriophage?

Back 22

They inject their genes and leave the rest of the virus particle behind

Front 23

What composes a T4 bacteriophage?

Back 23

25 structural proteins and dsDNA (>134 genes)

Front 24

T4 life cycle 1: How is the DNA of a bacteriophage inserted into the cell?

Back 24

1.) Virus attaches to surface receptors

2.) Tail contracts & lytic enzumes break the cell wall so core needle can pinch cell

3.) Content of the head (proteins, DNA) is released into cell

Front 25

T4 life cycle 2: How is the genetic info of a virus replicated in the cell?

Back 25

1.) Bacterial metabolism is disrupted and genomic DNA degraded

2.) Viral DNA is transcribed into mRNA

3.) Viral DNA is replicated in the bacteria

4.) mRNA is translated into viral proteins (>134)

Front 26

T4 life cycle 3: How is the virus reproduced?

Back 26

1.) Complex virus self-assembles

2.) 50-100 phages assemble in the infected cell

3.) Lytic proteins (lysozyme) disintegrates cell and releases phages

Front 27

What type of organism do enveloped viruses most commonly infect?

Back 27

Humans

Front 28

Give some examples of enveloped viruses that infect humans

Back 28

1.) influenza

2.) HSV1 (herpes)

3.) HIV

4.) vaccinia

Front 29

Through what 2 ways can enveloped viruses enter the cell? Give examples of viruses that do both

Back 29

1.) Fuse with plasma membrane and expell contents

e.g. HIV and HSV1 (herpes)

2.) Bind and be endocytosed

e.g. Hep B, influenza and polio

Front 30

What form of entry do naked viruses usually use? Give an example of 1

Back 30

Endocytosis

e.g. rhinoviruses (cold-causing)

Front 31

What are the 9 stages of the life cycle of an enveloped virus?

Back 31

1.) Binding 2.) Endocytosis

3.) Transport 4.) Fusion

5.) Trnascription & replication

6.) Translation 7.) Assembly

8.) Budding 9.) Release

Front 32

What happens to the envelope of a virus upon entering the cell?

Back 32

It breaks down in order to expel its contents

Front 33

How do viruses transport their contents to nucleus upon entering the cell?

Back 33

Intracellular transport machinery e.g. microtubules and F-actin

Motor proteins also used

Front 34

How long can small virus droplets remain airborne for?

Back 34

Hours to days

Front 35

How far can a virus droplet travel?

Back 35

~2m

Front 36

How many droplets are released per cough and at what speed?

Back 36

~3000

50mph

Front 37

How many droplets are released per sneeze and at what speed?

Back 37

~40000

100mph

Front 38

In a public environment, how many virus particles can be found per cubic meter of air?

Back 38

~16000