Micro Exam 4: 2013

Front 1

Acellular Definition?

Examples?

Back 1

Noncellular

Viruses, Prions, and Viroids.

Front 2

What Characteristics of life do acellular agents lack? (4)

Back 2

1. No cell structure or cell membranes
2. no metabolism
3. do not reproduce independently, utilize structures of host cell.
4. do not grow or respond to the environment.

Front 3

Virus?

Back 3

Miniscule, acellular, infectious agent having one or several pieces of nucleic acid-DNA or RNA.

Front 4

Genome of the Virus?

Back 4

The nucleic acid(s).

Front 5

Viruses have an _______________ and an _______________ state.

Back 5

Extracellular (outside of cell)

Intracellular (inside of cell)

Front 6

Virion?

Back 6

A virus in the extracellular state (outside of the cell).

Front 7

Capsomere?

Back 7

The proteinaceous subunit of a capsid.

Can have one type of protein or several types.

Front 8

Capsid?

Back 8

The protein coat surrounding the nucleic acid core within a virion.

Front 9

Nucleocapsid?

Back 9

The nucleic acid and its capsid together.

Front 10

Envelope?

Back 10

Phospholipid membrane that surrounds the nucleocapsid.

Not all virions have this.

Front 11

Recognition Sites?

Back 11

Bind to complementary chemicals on the surfaces of their specific host cells.

Front 12

When is the capsid removed from the virus?

Back 12

After the virus enters the intracellular state (once it's inside the host cell).

Front 13

How are viruses compared? (6)

Back 13

1. Type of genetic material
2. What kind of cells they attack
3. Shape
4. Size
5. Capsid Coat Nature
6. Envelope Presence/Absence

Front 14

Viral Genome Classes?

Back 14

1. dsDNA
2. ssRNA
3. ssDNA
4. dsRNA

Front 15

The genome of the virus may be ___________ and composed of several molecules of nucleic acid, or it can be ___________ or ____________.

Back 15

1. Linear
2. Circular
3. Singular

Front 16

Viral Genomes are larger than cell genomes. (T/F)

Back 16

False.

Front 17

Hosts of Viruses?

Back 17

Most viruses only infect certain hosts.

They can also be cell specific within a host.

Front 18

Generalists?

Example?

Back 18

A virus that infects many kinds of cells in many different hosts.

West Nile Virus.

Front 19

Bacteriophage/Phage?

Back 19

A virus that infects bacteria.

Outnumbers all bacteria, archea, and eukaryotes put together.

Front 20

Virion Shapes? (3)

Back 20

1. Helical
2. Polyhedral
3. Complex

Front 21

Helical Virus Capsid?

Back 21

Capsomeres bonded together in a spiral fashion to form a tube around the nucleic acid.

Front 22

Polyhedral Virus Capsid?

Back 22

roughly spherical.

Front 23

Most common Polyhedral Shape?

Back 23

Icosahedron (20 sides).

Front 24

Complex Virus Capsids?

Back 24

Many different shapes that don't fit into other categories.

Front 25

Parasites have?

Back 25

2 hosts (Definitive & Intermediate)

Front 26

Definitive Hosts?

Back 26

mature forms of parasite are present and reproducing.

Front 27

Intermediate Host?

Back 27

immature parasites undergo various stages of maturation. "juvenile arthropods"

Front 28

Parasites infect humans in what 3 ways?

Back 28

1. Ingested through vector-borne transmission
2. direct contact
3. penetration of skin/mucous membranes

Front 29

Protozoa parasites enter the body through what 2 morphological forms?

Back 29

1. Trophozoite
2. Cyst

Front 30

Trophozoite?

Back 30

feeding/reproducing stage that lives with in the host (active)

Front 31

Cyst?

Back 31

survives in the environment and is infective to new host. (dorment)

Front 32

Parasites are based on what 4 modes of locomotion?

Back 32

1. Ciliates
2. Amoebae
3. Flagellates
4. Apicomplexans

Front 33

Ciliates?

Back 33

"Balantidium Coli"....protozoa in the trophozoite stage and use cilia for locomotion ---> acquiring food. (basically a parasite in the GI tract of animals AKA Pig)

Front 34

Amoebae?

Back 34

protozoa with no defined shape and move/acquire food through use of pseudopodia. (in water & large intestine)

Front 35

Flagellates? What 3 stages in its life cycle?

Back 35

- protozoa that posses 1 long flagellum used for movement.
- Trypomastigotes, Epimastigotes, Amastigotes.

Front 36

Apicomplexans?

Back 36

alveolate protozoa whose infective forms are characterized by an ornate complex of organelles at their apical ends ---> non-motile/spore-like shapes. (mosquito!)

Front 37

Entamoeba Histolytica?

Back 37

carried asymptomatically through digestive tracts, occurs through drinking H20 contaminated with feces.

Front 38

3 types of Amebiasis?

Back 38

1. Luminal Amebiasis
2. Amebic Dysentery
3. Invasive extraintestinal amebiasis

Front 39

Luminal Amebiasis?

Back 39

in healthy people, asymptomatic, trophozoites remain in lumen of intestine. (little tissue damage)

Front 40

Amebic Dysentery?

Back 40

more serious/common, diarrhea/colitis/ulcertation ---> bloody mucus- containing stools.

Front 41

Invasive extraintestinal amebiasis?

Back 41

most serious, trophozoites invade peritoneal cavity & bloodstream. (found in liver, spleen, lungs, kidneys, and brain)

Front 42

What are the 2 rare Amoebaes that cause infections in the brain and are found in water?

Back 42

Acanthanmoeba and Naegleria

Front 43

Acanthanmoeba?

Back 43

enters through cuts/scrapes on skin through conjunctivia abrasions from contact lens/trauma

Front 44

Naegleria?

Back 44

flagellated form in addition to amoeboid/cyst stages.

Front 45

Amebic Encephalitis?

Back 45

common disease w/ Acanthamoeba causing headache/altered mental state/neurological deficit. symptoms worsen then you die.

Front 46

Amebic Meningoencephalitis?

Back 46

disease in brain with naegleria --> inflammation of brain/meningies (death with in 3-7 days)

Front 47

Trypanosoma Cruzi causes what? Is in most? Transmission through?

Back 47

causes Chaga's disease, most mammals/humans harbor organism. Transmission through bite of true bugs (sucking bugs feed from BV in lips ---> "kissing bugs")

Front 48

What are the 5 Flagellate parasites?

Back 48

1. Trypanosoma Cruzi
2. Trypanosoma Brucei
3. Leishmania
4. Giardia intestinalis
5. Trichomonas Vaginalis

Front 49

Chaga's Disease has what 4 stages?

Back 49

1. Acute stage
2. Generalized stage
3. Chronic stage
4. Symptomatic stage

Front 50

Acute stage in Chagas disease?

Back 50

swelling @ sites of bugs (the bite ---> aka chagoma)

Front 51

Generlaized stage in Chagas disease?

Back 51

with fever, swollen lymph nodes, myocarditis, enlargement of spleen, esophagus & colon. (in blood)

Front 52

Chronic stage in Chagas disease?

Back 52

asymptomatic and last for years

Front 53

Symptomatic stage in Chagas disease?

Back 53

results in heart failure (form pseudocysts --> clumps of amastogotes)

Front 54

Trypanosoma Brucei?

Back 54

- "african sleeping sickness" (coma)
- involves the Tseste fly that either bites you or if you eat animal that has been bitten.

Front 55

This ciliated parasite is a major cause of dysentery and balantidiasis characterized by persistent diarrhea and abdominal pain...

Back 55

B. Coli

Front 56

The arthropod vector of the disease African Sleeping Sickness...

Back 56

Tsetse fly

Front 57

Parasitic protozoan responible for sexually transmitted diseases in humans...

Back 57

Trichomonas

Front 58

Parastic helminth responsible for elephantitis...

Back 58

Wuchereria

Front 59

Untreated African Sleeping Sickness can invade the ___________ causing _________. Which is _____% fatal if left untreated.

Back 59

1. Central Nervous System
2. Meningoencephalitis
3. 100%

Front 60

Leishmania?

Back 60

protozoa hosted by wild/domestic dogs and small rodents.

Front 61

What are the 2 developmental stages in Leishmania?

Back 61

1. Amastigotes
2. Promastigotes

Front 62

Amastigotes?

Back 62

In Leishmania, lack flagella & multiply w/ in a mammalian host macrophages & monocytes.

Front 63

Promastigotes?

Back 63

In Leishmania, has a single anterior flagellum & develops extracellularly w/ in vectors gut. Double flagullated. All involves a sand fly which ingests WBC's containing Amastigotes during a blood meal.

Front 64

What are the 3 clinical forms of Leishmania?

Back 64

1. Cutaneous
2. Mucocutaneous
3. Visceral

Front 65

Mucocutaneous Leishmania?

Back 65

when skin lesions enlarge to encompass mucous membrane of mouth, nose or soft palate. Damage is severe & permanently disfiguring. (Picture of guy on Pg 658)

Front 66

Visceral Leishmania?

Back 66

95% fatal if untreated, macrophages spread the parasite to the liver, spleen, bone marrow & lymph nodes.

Front 67

Giardia?

Back 67

common waterbourne gastrointestinal disease by eating unwashed raw fruits/veggies that're contaminated by feces/water.

Front 68

Trichomonas- Vaginalis?

Back 68

- Parasite that lives on vulvas & in vaginas of women...urethras/prostates in men. Transmitted via sex... (STD --> Trich.)
- Causes inflammation of urethra/bladder in men.

Front 69

Vaginosis?

Back 69

Trich condition in women, containing pus-filled odorus discharge, lesions, ab pain & painful urination/intercourse.
(Trophozoites feed on vaginal tissue, leading erosion of epithelium)

Front 70

4 Apicomplexan Parasites?

Back 70

1. Plasmodium
2. Toxoplasma
3. Cryptosporidium
4. Cyclospora

Front 71

Plasmodium is a _____________ parasite. Describe it.

Back 71

- Apicomplexan
- Causes Malaria, where the parsites mesquito vector breeds --> attacks RBC's.

Front 72

What are 4 species of Plasmodium?

Back 72

1. P. Falciparum
2. P. Vivax
3. P. Ovale
4. P. Malariae

Front 73

What are the 3 stages of Plasmodium?

Back 73

1. Exoerythrocytic phase
2. Erythrocytic phase
3. Sporogonic phase

Front 74

Exoerythrocytic phase in Plasmodium?

Back 74

occurs outside of RBC's. (first 3 stages in life cycle of Plasmodium)

Front 75

Erythrocytic phase in Plasmodium?

Back 75

Begins when free merozoites penetrate RBC's and become in the trophozoite stage which endocytizes the RBC's hemoglobin protein. (stages 4 & 5 in Plasmodium)

Front 76

Sporogonic phase in Plasmodium?

Back 76

begins when female mosquito feeding on infected human ingests gametocytes within RBC's. (stages 6-9 in Plasmodium)

Front 77

4 genetic traits that increase their resistance to Malaria?

Back 77

1. Sickle-cell trait
2. Hemoglobin C
3. Glucose 6 phosphate dehydrogenase
4. Duffy

Front 78

What is Sickle-cell trait?

Back 78

people produce abnormal type of hemoglobin called Hemoglobin S, which causes RBC's to be sickle-shaped and makes RBC's resist penetration by Plasmodium.

Front 79

What is Hemoglobin C trait?

Back 79

humans with 2 genes for Hemoglobin C are invulnerable to malaria. The mechanism by which this mutation provides protection is unknown.

Front 80

What is Glucose 6 phosphate dehydrogenase trait?

Back 80

genetic deficiency in which Trophozoites must acquire this enzyme from human host before the Trophzoite can synthesize DNA; humans without the enzyme are spared to malaria.

Front 81

What is Duffy trait?

Back 81

lack of antigens on RBC's. Because P. Vivax requires Duffy antigens to attach to and infect RBC's, Duffy-negative individuals are resistant to this species.

Front 82

Toxoplasma Gondii?

Back 82

25% of world is infected. Wild/Domestic animals and birds are major reservoirs. Cats are definitive host in which protozoan reproduces sexually. Get it by eating under-cooked meat containing the parasite or by inhalation/ingestion of contaminated soil.

Front 83

Majority of people with Toxoplasma Gondii show ________________, a small percentage develop ___________. Characteristics of disease?
More severe in who?

Back 83

- no symptoms
- Toxoplasmosis
- fever, headache muscle pain, sore throat, swollen lymph nodes/neck.
- AIDS patients and Fetuses.

Front 84

Cryptosporidium Enteritis? Life threatening to who?

Back 84

- disease of animals that's transmitted to people. C. Parvum causes the disease. Carried asymptomatically and found in waterways with contaminated livestock wastes.
- HIV +, reveals that a person also has AIDS.

Front 85

Cyclospora Cayetanensis? How do you get it? More severe to who?

Back 85

- waterbourne apicomplexan. Get by eating/drinking oocysts in contaminated food/water. Enters intestine causing cramps, watery diarrhea, myalgia (muscle pain), and fever.
- More severe in AIDS patients causing dehydration and weight loss.

Front 86

Poxviridae?

Back 86

Double stranded DNA virus

Front 87

Stages of the lesions on poxvirus infections? (6)

Back 87

1. Macule
2, Papule
3. Vesicle
4. Pustule
5. Crust
6. Scar

Front 88

Infections with poxviruses occur primarily through which 2 ways?

Back 88

1. inhalation of viruses in droplets or dried crusts

Front 89

2 main poxvirus diseases of humans?

Back 89

1. Smallpox
2. Molluscum contagiosum

Front 90

Small pox is commonly know as what?

Back 90

Variola

Front 91

2 forms/strains of Variola?

Back 91

Variola major and Variola minor

Front 92

Variola Major?

Back 92

cause severe disease and can be lethal compared to Variola Minor

Front 93

Variola Minor?

Back 93

less severe disease compared to Variola Major

Front 94

What do Variola major and minor have in common? (3)

Back 94

1. infect internal organs
2. cause fever
3. leave severe scars on the skin of survivors (especially face)

Front 95

Molluscum Contagiosum?

Back 95

1.Less severe compared to small pox
2. less noticeable, smaller, smooth, waxy pustules

Front 96

Where does Molluscum Contagiosum typically occur?

Back 96

Face, trunk, and external genitalia

Front 97

Herpesviridae?

Back 97

1. like to infect nervous tissue
2. can go dormant and be reactivated

Front 98

HHV-1?

Back 98

1. Known as "above the waist"
2. Produce itchy skin lesions on the lips known as Fever blisters or cold sores
3. can be accompanied by flulike symptoms

Front 99

HHV-2?

Back 99

1. Known as "below the waist"
2. associated with painful lesions on the genitalia (STD)

Front 100

Ocular Herpes Ocular?

Back 100

1. infection caused by latent (dormant) herpesviruses (HHV-1)
2. symptoms include: gritty feeling, conjunctivitis, pain, and sensitivity to light.

Front 101

Whitlow?

Back 101

occurs when either HHV-1 or HHV-2 enters enters a cut or break in the skin of a finger

Front 102

Neonatal Herpes?

Back 102

caused by HHV-2
fetus can be infected in utero if the virus crosses the placental barrier, but more likey for a baby to be infected at birth if a cesarean section is not performed

Front 103

Human Herpesvirus 3 is commonly known as?

Back 103

VZV- Varicella- Zoster Virus

Front 104

Varicella is commonly called what?

Back 104

Chicken Pox

Front 105

Shingles?

Back 105

The reactivated form of chicken pox that is extremely painful at the distal end of the nerve.

Front 106

dermatome?

Back 106

localization of shingle lesions along a band of skin

Front 107

HHV-4?

Back 107

known as the Epstein-Barr Virus (EBV)

Front 108

2 Diseases EBV is known for?

Back 108

1. Burkitt's Lymphoma
2. infectious mononucleosis (mono)- "kissing disease"

Front 109

EBV is an etiological agent of ? (4)

Back 109

1. nasopharyngeal cancer
2. chronic fatigue syndrome
3. oral hairy leukoplakia
4. Hodgkins lymphoma

Front 110

HHV-5

Back 110

Cytomegalovirus; CMV (cells infected become large)

Front 111

CMV transmission? (7)

Back 111

bodily secretions, including saliva, mucus, milk, urine, feces, semen, and cervical secretions

Front 112

CMV may also be?

Back 112

teratogenic (cause birth defects)

Front 113

Which HHV is know to have an "owl eye" cell?

Back 113

HHV-5 CMV (cytomegalovirus)

Front 114

HHV_^ is in what genus?

Back 114

Roseolovirus which causes roseola

Front 115

Roseola?

Back 115

illlness in children causing abrupt fever, sore throat, enlarged lymph nodes, and a faint pink rash on the face, neck, trunk, and thighs

Front 116

what is MS linked to?

Back 116

HHV-6; Roseolovirus

Front 117

HHV-8 is known as ?

Back 117

Rhadinovirus

Front 118

Rhadinovirus?

Back 118

causes Kaposi's sarcoma- a cancer seen in aids patients

Front 119

virus associated with papillomaviridae?

Back 119

Papillomavirus

Front 120

papillomas?

Back 120

caused by the papillomaviruses; commonly known as warts

Front 121

condylomata acuminata?

Back 121

genital warts with cauliflower-like growth caused by the papillomaviruses

Front 122

Papillomavirus transmission? (2)

Back 122

direct contact and fomites

Front 123

Vaccine that protects against the most common strains of sexually transmitted papillomaviruses?

Back 123

Gardasil

Front 124

polyomaviruses (polyomaviridae)?

Back 124

group of viruses capable of causing several different tumors in animals and humans.

Front 125

2 human polyomaviruses?

Back 125

1. BK virus
2. JC virus

Front 126

BK and JC viruses?

Back 126

1. spread via the respiratory route
2. initially infect the lymphocytes
3. latent infections can become established in the kidneys

Front 127

progressive multifocal leukoencephalopathy (PML)

Back 127

rare and fatal disease caused by the latent infections of the JC virus that reach the brain

Front 128

Adenoviridae?

Back 128

one of the many causative agents of the "common cold"

Front 129

adenoviruses can also cause? (2)

Back 129

1. mild diarrhea in children
2. pinkeye

Front 130

Hepadnaviridae? (3)

Back 130

1. partially dsDNA and partially ssDNA
2. responsible for the Hepatitis B virus (HBV)
3. effects the liver

Front 131

Hepatitis B infections? (2)

Back 131

1. Only DNA virus that causes hepatitis
2. co-infection with hep D virus can cause permanent liver damage
3. AKA serum hepatitis

Front 132

Jaundice?

Back 132

a yellowing of the skin and eyes ---> occurs when a greenish-yellowish wast product called bilirubin accumulates in the blood.

Front 133

the role of HBV in hepatic cancer? (4)

Back 133

1. large number of hepatic cancer cases in geographic areas that also have high prevalence of HBV
2. The HBV genome has been found integrated into hepatic cancer cells
3. hepatic cancer cells typically express HBV antigen
4. Chronic carriers of HBV are 200 times more likely to develop hepatic cancer than are noncarriers.

Front 134

Parvoviruses?

Back 134

the only pathogens of humans with a ssDNA genome
the smallest of the DNA viruses

Front 135

the primary parvovirus of humans? and it is in what genus?

Back 135

1. B19 virus
2. Erythrovirus

Front 136

what causes erythema infectiosum (fifth disease)?

Back 136

B19 Virus

Front 137

what is erythema infectiosum or fifth disease?

Back 137

infectous reddening of the skin----> sunlight induced

Front 138

Lytic Replication?

Back 138

The replication cycle in which the host cell usually lyses or dies.

Front 139

The 6 Stages of Lytic Replication?

Back 139

1. Attachment
2. Entry
3. Bacterial Chromosome Degraded
4. Synthesis
5. Assembly
6. Release

Front 140

Lysogenic Replication?

Back 140

Process of viral replication in which a bacteriophage enters a bacterial cell, inserts into the new DNA of a host, and remains inactive. Phage will replicate and later will leave the chromosome.

Front 141

The 8 Stages of Lysogenic Replication?

Back 141

1. Attachment
2. Entry
3. Prophage in Chromosome
4. Replication of chromosome and virus; cell division(s)
5. Induction
6. Synthesis
7. Assembly
8. Release

Front 142

The 5 Basic Steps of Animal Virus Replication?

Back 142

1. Attachment
2. Entry
3. Synthesis
4. Assembly
5. Release
(6. Latency; only in some animal viruses!!)

Front 143

What do animal viruses typically use for attachment (step 1)?

Back 143

Typically have glycoprotein spikes or other attachment molecules on their capsids or envelopes.

Front 144

The 3 mechanisms of entry for animal viruses?

Back 144

1. Direct Penetration
2. Membrane Fusion
3. Endocytosis

Front 145

Direct Penetration of animal virus?

Back 145

Viral capsid attaches and sinks into the cytoplasmic membrane.

Front 146

Membrane Fusion of animal virus?

Back 146

the viral envelope and host cell membrane fuse, releasing the capsid into the cells cytoplasm

Front 147

Endocytosis of animal virus?

Back 147

cytoplasmic membrane engulfs virus.

Front 148

What are the 3 parasitic helminths?

Back 148

1. Cestodes
2. Trematodes
3. Nematodes

Front 149

Cestodes are also known as ________. Tell me about them.

Back 149

- Tapeworms
- No digestive system, are primitive, have a scolex (small organ that has suckers/hooks attached to tissues), proglottids (grows from neck remaining attached), strobilae (chain of proglottids), & gravid (full of fertilized eggs).

Front 150

What are the 3 types of Cestodes?

Back 150

1. Taenia Saginata
2. Taenia Solium
3. Echinococcus Granulosus

Front 151

Taenia Saginata is known as ______ which is in _____.

Back 151

-beef tapeworm
-cows

Front 152

Taenia Solium is known as _______ which is in ______.

Back 152

-pork tapeworm
-pigs

Front 153

Echinococcus Granulosus is known as ________ which is in _____. It can form ______.

Back 153

-dog tapeworm
-dogs
- can form "hydatid" ---> cysts in any organ but mainly in the liver.

Front 154

Trematodes are also known as ______/_______. Tell me about them. What are they in?

Back 154

- Flukes/Flatworms.
- Incomplete digestive system w/ only one opening, shorter than a tapeworm and is Monoecious (in all flukes, not self-fertile)
- Snail/Fish/Plant.

Front 155

What are the 2 types of Trematodes?

Back 155

1. Liver Flukes
2. Blood Flukes

Front 156

Liver Flukes? What are its 2 species?

Back 156

- Infect sheep/cattle, can infect humans. Larva leaves intestines & goes into bile ducts in the liver.
1. Fasciola Hepatica
2. Fasciola Gigantica

Front 157

Blood Flukes are in the genus of ____________ which causes ____________. What is that?

Back 157

- Schistosoma
- Schistosomiasis
- potentially fatal disease and 1 of the major health problems in the world.

Front 158

What are the 3 geographically limited species of Schistosoma that infect humans? Where do you find them? What area of the body do they effect?

Back 158

1. S. Mansoni (Caribbean, Venezuela, Brazil, Arabia & Africa) *INTESTINAL*
2. S. Haematobium (Africa & India) *BLADDER/URETERS*
3. S. Japonicum (China, Taiwan, Phillippines, & Japan) *INTESTINAL*

Front 159

Nematodes are also known as ________. Tell me about it.

Back 159

- Roundworms
- Most complex, complete digestive system, has 2 openings.

Front 160

What are the 4 types of Nematodes?

Back 160

1. Ascaris Lumbricoides
2. Hookworms
3. Enterobius Vermicularis
4. Wuchereria Bancrofti

Front 161

Ascaris Lumbricoides?

Back 161

- Most common nematode, in tropical regions, largest nematode (30 CM IN LENGTH!), produce 200,000 eggs a day, develop in human intestines, can be fatal, treatment is 90% effective with use of Albendazole & Mebendazole.

Front 162

Hookworms also goes by __________ & ____________. Tell me about it.

Back 162

- Ancyiostoma & Necator
- Go through skin to BV to heart & lungs. Cough up & swallow ---> goes to intestines. Leads to rash or inflammatory response. Get from being barefoot.

Front 163

Enterobius Vermicularis is also known as _________. Tell me about it.

Back 163

- Pinworms
- Eggs are deposited around the anus. Usually ingested by tainted food/water. You know you have it by insane itching on your anus.

Front 164

Wuchereria Bancrofti?

Back 164

Nematode that causes "Filariasis", infects lymphatic system. End result is "Elephantiasis" in which tissues enlarge & harden in certain areas. (legs)

Front 165

Synthesis of Animal Viruses? (in general)

Back 165

Each type (DNA or RNA---ds or ss) of animal virus has their own strategy for synthesis.

Front 166

dsDNA Synthesis?

Back 166

1.) dsDNA genome enters the nucleus of the cell and the cellular enzymes replicate the viral DNA in the same manner as they replicate host DNA.

2.) mRNA is transcribed from viral DNA in the nucleus and capsomere proteins are made in the cytoplasm by host ribosomes.

3.) Capsomeres enter nucleus and virions spontaneously assemble.

Front 167

The 2 exceptions of regimen of dsDNA viruses?

Back 167

1. Poxviruses do all their synthesis in the host cell's cytoplasm and never enters the nucleus.

2. Hep. B uses RNA as an intermediary instead of replicating DNA from a DNA template.

Front 168

ssDNA Virus synthesis?

Back 168

Parvo virus.

1. Enters nucleus of cell
2. Host enzymes produce new strand of DNA complementary to the viral genome.
3. The new complementary Strand bonds to ssDNA of the virus to form a dsDNA molecule.

Front 169

4 Types of RNA viruses?

Back 169

1. Positive sense ssRNA (+ssRNA)
2. Retroviruses (kind of +ssRNA)
3. Negative sense ssRNA (-ssRNA)
4. dsRNA

Front 170

positive-strand RNA (+RNA)?

Back 170

single-stranded viral RNA that can act directly as mRNA.

Front 171

+ssRNA Virus synthesis?

Back 171

A complementary negative-strand RNA is transcribed from the +ssRNA genome by viral RNA polymerase.

The -RNA then serves as a template for multiple +ssRNA genomes.

Front 172

+ssRNA Retrovirus synthesis?

Back 172

Use a DNA as an intermediary that is transcribed from +RNA by reverse transcriptase carried within the capsid. The DNA intermediary acts as a templatefor the synthesis of additional +RNA molecules, which act both as mRNA for protein synthesis and as genomes for new virions.

Front 173

+ssRNA retrovirus example?

Back 173

HIV

Front 174

Negative Sense ssRNA (-ssRNA) synthesis?

Back 174

Overcomes a unique problem with -RNA not recognized by ribosomes by carrying an enzyme within its capsid called RNA-dependent RNA transcriptase which transcribes +RNA from the virus' -RNA genome.

Translation then occurs as normal.

Front 175

-ssRNA examples? (2)

Back 175

Rabies and the Flu.

Front 176

dsRNA Virus synthesis?

Back 176

Positive strand of the molecules serves as the mRNA for the translation of proteins, one of which is an RNA polymerase that transcribes dsRNA. Acts similar to that of regular DNA synthesis.

Front 177

dsRNA example?

Back 177

rotavirus- responsible for diarrhea in infants.

Front 178

Neoplasia?

Back 178

uncontrolled cell division within a multi cellular animal

Front 179

tumor?

Back 179

mass of neoplastic cells

Front 180

benign tumor?

Back 180

does not travel through out body (stays in one place)
generally not harmful

Front 181

malignant tumor?

Back 181

travels throughout body and invades tissues and organs by creating new tumors.

Front 182

Metastasis?

Back 182

process of malignant tumors invading other tissues and organs, creating new tumors.

Front 183

cancers?

Back 183

malignant tumors

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oncogenes and protooncogenes?

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oncogenes are genes that promote cancer (active form)

Protooncogenes are the INACTIVE form of oncogenes.

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4 factors that activate oncogenes?

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-UV Light
-Radiation
-Carcinogens
-viruses

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what percent of cancers do viruses cause?

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20-25%

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How do viruses cause cancer? 3 ways

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-carries oncogenes in its genome
-promotes oncogenes in body
-inserts itself into the repressor genes for oncogenes.

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Viruses that cause cancer? 6

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Herpesviridae
hepadnoviridae
papillomaviridae
adenoviridae
polyomaviridae
retroviridae

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Culturing Viruses in Bacteria?

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used for bacteriophages; easy to grow and culture

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Plaques?

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clear zones on bacterial medium where cells have lysed.

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Animal/Plant Cultures?

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-Ethical Issues for animals
-1st discovery and isolation of a virus done on the tobacco plant (TMV)
Can be costly as well to maintain

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Culturing Viruses in Chicken Eggs?

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-Inexpensive, Largest among cells
-Free of contaminating mirobes
-Self sufficient
-VACCINES SOMETIMES PREPARED THIS WAY

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Viruses in cell culture?

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-Medium with one type of cell on it (isolated from an organism)
-also called tissue cultures, but not very accurate

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Cell Culture Types?

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Diploid Cell Cultures

Continuous cell cultures

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Diploid Cell Culture?

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Created from embryonic plant, animal, or human cells that have been isolated and provided appropriate growth conditions.

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Continuous Cell Culture? Example?

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Longer lasting because they are derived from tumor cells(divides relentlessly).

-HeLa Cells