Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

NBDE Part 1 > Microbiology Virology > Flashcards

Microbiology Virology Flashcards

1
Q

What is a Virion and how are viruses characterized?

A
  • Virion: Infectious; complete virus particle (DNA/RNA + protein)
  • Virus Characterization:
    • Characterized by single- or double-stranded DNA or RNA (never both) surrounded by a protein capsid
      • Repeating polypeptide subunits (capsomeres)
      • Protects viral genome from extracellular nucleases
      • Essential for infectivity of virus
      • Antigenic; provokes host immune response
      • Serves as attachment protein in nonenveloped viruses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain haploid/diploid nature of viruses as well as where RNA and DNA viruses replicate and their hardware

A
  • All viruses are haploid (1 copy of RNA/DNA)
    • EXCEPT: Retroviruses = diploid
  • All RNA viruses replicate in the cytoplasm using their own RNA polymerase
    • EXCEPT: retrovirus and orthomyxovirus
  • All DNA viruses replicate in the nucleus using host RNA polymerase
    • EXCEPT: poxvirus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the following:

  • Nucleocapsid
  • Envelop
  • Viroid
A
  • Nucleocapsid: Nucleic acid core + protein capsid
  • Some viruses have an outer membrane called an envelope, which is composed of plasma membrane lipoproteins and glycoproteins obtained as the virus leaves its host cell (budding)
  • Viroid: a Single molecule of circular RNA without a protein envelope. Causes plan diseases
  • Virus Facts:
    • Do not contain mitochondria or ribosomes; must replicate within living host cells
    • Not visible by light microscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the viral growth curve

A
  • Latent phase: Viral penetration -> viral release 10-12 hours
  • Eclipse phase: viral penetration -> viral assembly within host cell.
    • No virus can be detected during this phase
  • Rise phase: Viral assembly -> viral release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain Viral Replication steps

A
  • Attachment: Determined by the specificity of viral proteins to host cells
  • Penetration: Via receptor-mediated endocytosis (eg. pinocytosis)
  • Uncoating: Viral nucleic acid is spilled into the cytoplasm
  • Transcription and Translation:
    • All DNA viruses (except poxviruses) replicate in the nucleus using host cell RNA polymerase
    • All RNA viruses (except retroviruses and orthomyxoviruses) replicate in the cytoplasm using their RNA polymerase. Transcription is only necessary for viruses whose RNA has a negative polarity (a virus’s RNA that has positive polarity serves as the mRNA itself)
    • All Retroviruses use their own reverse transcriptase for transcription
  • Assembly : The new viral nucleic acid and capsid proteins are packaged
  • Released : Either by budding through the host plasma membrane (creating a viral envelope) or by host plasma membrane rupture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain the following viruses and terminologies:

  • Cytopathic effect (CPE)
  • Enteroviruses
  • Roboviruses
  • Arboviruses
A
  • One virion can replicate to form hundreds of progeny viruses
  • The host cellular morphologic and functional changes associated with viral replication and release are known as the cytopathic effect (CPE).
    • CPE is often specific for a particular virus. Not all viruses cause CPE
  • Enteroviruses : Poliovirus, Coxsackieviruses and hepatitis A
  • Roboviruses: Are rodent-borne viruses (rodent excrement): hantavirus (sin Nombe viruses)
  • Arboviruses : are arthropod-borne viruses (mosquitoes, ticks): West Nile virus, yellow fever virus, Dengue virus, Colorado tick fever virus and Eastern/Western encephalitis virus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the structure of HIV

A
  • HIV contains two strands of RNA (diploid) and reverses transcriptase
  • Two important envelope protein:
    • gp120 (mediates attachment to CD4)
    • gp41 (mediates fusion to the host cell)
  • The nucleocapsid is composed of p24 and p7
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain viral antigenic changes

A
  • Antigenic changes contribute to the cause of epidemic and pandemics
  • Commonly associated with influenza viruses (orthomyxoviruses)
  • There are two modes of antigenic changes:
    • Antigenic drift : Minor changes caused by genetic mutations
    • Antigenic shift : Major changes caused by genetic reassortment

NOTE: Influenza viruses have two envelope glycoprotein spikes, hemagglutinin and neuraminidase, which exhibit the majority of antigenic changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the RNA Nonenveloped Viruses in order of increasing size

A
  • Picornavirus (smallest RNA) - single/linear
  • Calicivirus - Single/linear
  • Hepevirus - Single/linear
  • Reovirus - Double/linear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What makes up the Picornaviruses

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

Picornaviruses​​

  • Poliovirus (single, linear)
    • Polio
      • Antiviral: None
      • Vaccine: Yes (Salk, Sabin)
  • Echovirus (single, linear)
    • Aseptic meningitis
      • Antiviral: None
      • Vaccine: No
  • Rhinovirus (single, linear)
    • Common Cold
      • Antiviral: None
      • Vaccine: No
  • Coxsackie A Virus (single, linear)
    • Herpangia: (soft palate, posterior pharynx)
    • Hand-Foot-&-Mouth disease: (Palms, soles, anterior oral mucosa)
    • Acute lymphonodular pharyngitis
    • Aseptic meningitis
      • Antiviral: None
      • Vaccine: No
  • Coxsackie B Virus (single, linear)
    • Pleurodynia
    • Myocarditis
    • Pericarditis
    • Aseptic meningitis
      • Antiviral: None
      • Vaccine: No
  • HAV (single, linear)
    • Hepatitis A
      • Antiviral: None
      • Vaccine: YES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What makes up the Calicivirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

Calicivirus

  • Norwalk virus (single, linear)​
    • Gastroenteritis (adults)
      • Antiviral: None
      • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What makes up the Hepevirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

Hepevirus

  • HEV (single, linear)
    • Hepatitis E
      • Antiviral: None
      • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What makes up the Reovirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Reovirus

  • 1: Rotavirus (double; linear)
    • Gastroenteritis (infants)
      • Antiviral: None
      • Vaccine: No
  • 2: Coltivirus (double; linear) - only virus transmitted by ticks
    • Colorado tick fever
      • Antiviral: None
      • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name the RNA-Enveloped Viruses in order of increasing Size

A
  • Deltaviruse (Single, circular)
  • Flavivirus (Single, linear)
  • Togavirus (Single, linear)
  • Orthomyxovirus (Single, linear)
  • Retrovirus (Single, linear)
  • Paramyxovirus (Single, linear)
  • Rhabdovirus (Single, linear)
  • Filovirus (Single, linear)
  • Coronavirus (Single, linear)
  • Bunyavirus (Single, circular)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What makes up the Deltavirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Deltavirus

  • HDV (single; circular)
    • Hepatitis D
      • Antiviral: alpha-interferon
      • Vaccine: Yes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What makes up the Flavivirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Flavivirus

  1. Japanese encephalitis virus (single, linear)
    • Encephalitis
      • Antiviral: None
      • Vaccine: Yes
  2. Yellow fever virus (single, linear)
    • Yellow fever
      • Antiviral: None
      • Vaccine: Yes
  3. West Nile Virus (single, linear)
    • Encephalitis
      • Antiviral: None
      • Vaccine: No
  4. Dengue Virus (single, linear)
    • Dengue fever
      • Antiviral: None
      • Vaccine: No
  5. HCV (single, linear)
    • Hepatitis C
    • Hepatocellular Carcinoma (associated)
      • Antiviral: alpha-interferon, Ribavirin
      • Vaccine: NO
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What makes up the Togavirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Togavirus

  1. Rubella virus (single, linear)
    • Rubella (German 3-day measles) Truncal rash, Teratogen
      • Antiviral: None
      • Vaccine: YES
  2. Eastern/Western encephalitis virus (single, linear)
    • Encephalitis
      • Antiviral: None
      • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What makes up the Orthomyxovirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Orthomyxovirus

Exhibit various antigenic changes

Replicate in nucleus

  • Influenza Virus (single, linear)
    • Influenza
    • Reye’s Syndrome (association)
      • Antiviral: Amantidine, Rimantidine, Zanamivir, Oseltamivir
      • Vaccine: YES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What makes up the RETROVIRUS

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the RETROVIRUS

Uses reverse transcriptase

Replicates in nucleus

Diploid

  1. HTLV (single, linear)
    • Adult T-cell leukemia/lymphoma
    • Chronic progressive myelopathy
      • Antiviral: None
      • Vaccine: No
  2. HIV (single, linear)
    1. Infects CD4 T-helper cells
    2. Diagnosis confirmed by Western blot
      • AIDS
        • Antiviral: Zidovudine (AZT), Lamivudine, Stavudine, Indinavir, Ritonavir
        • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What makes up the Paramyxovirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Paramyxovirus

  1. Measles virus (single, linear)
    • Measles (rubeola)
      • Nonpruritic maculopapular brick-red rash
      • Multiple white lesions (Koplik’s spots) are often seen on the buccal mucosa
        • Antiviral: None
        • Vaccine: YES
  2. Mumps virus (single, linear)
    • Mumps
      • Parotitis, orchitis, deafness​
        • Antiviral: None
        • Vaccine: YES
  3. RSV = INFANTS ONLY (single, linear)
    • Bronchiolitis
    • Pneumonia
      • Antiviral: Ribavirin
      • Vaccine: No
  4. Parainfluenza virus (single, linear)
    • Croup
    • Bronchiolitis
    • Common cold
      • Antiviral: None
      • Vaccine: No
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What makes up the Rhabdovirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Rhabdovirus

  • Rabies Virus (single, linear)
    • Rabies
      • Antiviral: None
      • Vaccine: YES
22
Q

What makes up the Filovirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Filovirus

  • Ebola Virus (single, linear)
    • Ebola
    • Hemorrhagic Fever
      • Antiviral: None
      • Vaccine: No
23
Q

What makes up the Coronavirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Coronavirus

  • Coronavirus (single, linear)
    • Common Cold
    • SARS
      • Antiviral: None
      • Vaccine: No
24
Q

What makes up the Bunyavirus

  • Virus Name (single/double; linear/nonlinear)
    • Disease
      • Antiviral treatment available
      • Vaccine available
A

What makes up the Bunyavirus

  • Hantavirus = Sin Nombre virus (single, circular)
    • Hantavirus
    • Hemorrhagic Fever
      • Antiviral: None
      • Vaccine: No
25
Which virus causes the following diseases: * **Herpangia** * Soft palate, posterior pharynx * **Hand-foot and mouth disease** * Palms, soles, anterior oral mucosa * Acute lymphonodular pharyngitis * Aseptic Meningitis
***_Coxsackie A virus_*** (Family: **Picornavirus** = Smallest RNA Virus) Nonenveloped (single, linear)
26
What virus causes the following diseases: Gastroenteritis (infants)
***_Rotavirus_*** (Family: **Reovirus**) RNA Nonenveloped: Double, linear In addition, **Coltivirus** also belongs in this family * only virus transmitted by ticks * Colorado tick fever
27
Which virus family includes the following diseases and/or viruses: - West Nile - Yellow Fever - HCV = Hepatitis C
Flavivirus RNA-Enveloped virus
28
Which virus family includes the following diseases and/or viruses: - HTLV and HIV
**_Retrovirus_** RNA-Enveloped Virus - Uses reverse transcriptase - Replicates in the nucleus - diploid
29
Which virus family includes the following diseases and/or viruses: - Rubella virus (Rubella = German 3 day measles)
***_Togavirus_*** Includes Rubella virus = **Rubella** (German 3 day measles) Truncal rash Teratogen
30
Which virus family includes the following diseases and/or viruses: Measles Virus Mumps Virus RSV Parainfluenza Virus
***_Paramyxovirus_*** RNA Enveloped Virus * **Measles Virus** * Measles (_rubeola_) * **Mumps Virus** * Mumps * **RSV** (Infants only) * Bronchiolitis, Pneumonia * **Parainfluenza Virus** * _Croup_
31
What virus is characterized by: 1. Nonpruritic maculopapular brick-red rash 2. Multiple white lesions on the buccal mucosa
***_Measles (Rubeola)_*** 1. Nonpruritic maculopapular brick-red rash 2. Multiple white lesions on the buccal mucosa 1. **KOPLIK'S SPOTS**
32
What are the major DNA Nonenveloped viruses in order of increasing size
* Parvovirus (Single, Linear) * Papillomavirus (Double, circular) * Polyomavirus (Double, circular) * Adenovirus (Double, linear)
33
What makes up the **Parvovirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the ***_Parvovirus_*** Note: ParVovirus * **_B19 Virus_** (DNA Non - single; linear) * **Aplastic anemia** (Sickle cell disease associated) * Erythema infectiosum (**fifth disease)** * Fetal infections * Antiviral: None * Vaccine: No
34
What makes up the **Papillomavirus** (Papovaviruses) * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **Papillomavirus** (Papovaviruses) * ***_HPV_*** (DNA non- double; circular) * Papillomas (warts) * Condyloma acuminatum (genital warts) * **Verruca** **vulgaris** * Cervical cancer * Antiviral: Podophyllin, alpha-interferon, Cidofovir * Vaccine: **YES**
35
What makes up the **polyomavirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **polyomavirus** * **_JC virus_** (DNA non- double; circular) * Progressive multifocal leukoencephalopathy (PML) * HIV associated * Antiviral: None * Vaccine: NO
36
What makes up the **Adenovirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **Adenovirus** * ***_Adenovirus_*** (DNA non - double; linear) * Pharyngitis * Conjunctivitis (pink eye) * Pneumonia * **Common cold** (**children** = Aden of children) * Antiviral: None * Vaccine: **YES**
37
What are the major DNA enveloped viruses from smallest to largest
* Hepadnavirus * Herpesvirus * Poxvirus
38
What makes up the **Hepadnavirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **Hepadnavirus** Has reverse transcriptase * ***_HBV_*** (DNA Env. double; circular) * **_Hepatitis B_** * **Hepatocellular carcinoma** (associated) * Antiviral: alpha-interferon, Lamivudine * Vaccine: **YES**
39
What makes up the **Herpesvirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **Herpesvirus** Lies dormant in **sensory nerve ganglia**, esp. trigeminal ganglion Obtains envelope from host nuclear membrane (not plasma membrane) **Tzanck test assay** for HSV-1, HSV-2, VZV 1. ***_HSV-1_*** (DNA Env double; linear) * **Herpes labialis** * Keratoconjunctivitis * Gingivostomatitis * Recurrent encephalitis * Antiviral: Acyclovir, Penciclovir, Valacyclovir, Famciclovir * Vaccine: No 2. ***_HSV-2_*** (DNA Env double; linear) * **Herpes genitalis** * Neonatal encephalitis * Aseptic meningitis * Antiviral: Acyclovir, Penciclovir, Valacyclovir, Famciclovir * Vaccine: No 3. ***_VZV_*** (DNA Env double; linear) * ***_Varicella_*** - primary * **Chickenpox** * Pruritic, macular lesions that become pustular and crusted * Reye's syndrome (associated) * ***_Zoster_*** - recurrent * **Shingles** * Usually localized to a single dermatome * Antiviral: Acyclovir, Valacyclovir, Famciclovir * Vaccine: No 4. ***_CMV_*** (DNA Env double; linear) * Congenital abnormalities * Primary viral cause of **mental retardation** * Cytomegalic inclusion disease * Antiviral: Ganciclovir, Valganciclovir, Foscarnet * Vaccine: No 5. ***_EBV_*** Ebstein Barr (DNA Env double; linear) * **_Infectious mononucleosis_** * Transmission: **Saliva** * **​​**"kissing disease" * Splenomegaly, necrotizing pharyngitis, increased abnormal lymphocytes * Heterophile test used for screening * Burkitt's lymphoma (association) * Nasopharyngeal carcinoma (association) * B-cell lymphoma (association) * Hairy leukoplakia (association) * Antiviral: None (self-limiting in 2-3 weeks) * Vaccine: No 6. ***_HHV-8_*** (DNA Env double; linear) * **Kaposi's Sarcoma** * Antiviral: None * Vaccine: No
40
What makes up the **Poxvirus** * Virus Name (single/double; linear/nonlinear) * Disease * Antiviral treatment available * Vaccine available
What makes up the **Poxvirus** 1. ***_Variola virus_*** (DNA Env - double; linear) * **_Smallpox_** = ERADICATED * Antiviral: None * Vaccine: **YES** 2. **_MCV_** (DNA Env - double; linear) * **Molluscum contagiosum** * Antiviral: None * Vaccine: No
41
What are the signs and symptoms of viral hepatitis?
fatigue myalgia loss of appetite nausea diarrhea constipation fever jaundice Hepatitis viruses are extremely heat resistant (more so than HIV) proper autoclaving kills all hepatitis viruses
42
What are the tests of liver function and how they rate to viral hepatitis and alcoholic hepatitis
**Tests of liver function** * Bilirubin * ALT (alanine aminotransferase) * AST (aspartate aminotransferase) **Viral vs. alcoholic hepatitis:** * **_Viral hepatitis_**: ALT \> AST * **_Alcoholic hepatitis_**: ALT \< AST
43
Compare the major Hepatitis viruses. State their: * Virus * Nucleic acid * Viral Class * Transmission * Characteristics * Vaccine: Y/N
* ***_HAV_*** * ss RNA * **Picornavirus** - No Env * Fecal-oral * Self-limiting; recovery in 4 months * Vaccine: Yes * ***_HBV_*** * ds DNA * **Hepadnavirus** - Yes Enveloped * Bloodborne * Increased incidence of chronic liver disease, cirrhosis, HCC * Vaccine: Yes * ***_HCV_*** * ss RNA * **Flavivirus** - Yes Enveloped * Bloodborne * Increased incidence of chronic liver disease, cirrhosis, HCC * Vaccine: No * ***_HDV_*** * ss RNA * **Deltavirus** - Yes Enveloped * Bloodborne * Requires presence of HBsAg for replication * Vaccine: Yes * ***_HEV_*** * ss RNA * **Calicivirus** - Not Enveloped * Fecal-oral * Causes occasional epidemics in underdeveloped countries * Vaccine: No
44
Explain the serological profile of Hepatitis infections * Virus * Acute infection * Chronic disease * Immunity
* ***_HAV_*** * _Acute infection_: IgM Anti-HAV * _Chronic disease:_ None * _Immunity:_ Anti-HAV * ***_HBV_*** * _Acute infection:_ **IgM Anti-HAB** , HBsAg, HBeHg * _Chronic disease:_ IgG Anti-HBc, HBsAg * Immunity: **Anti-HBs** * An individual ***_vaccinated_*** for HBV will show serology positive for ***_ONLY Anti-HBs_*** * ***_HCV_*** * _Acute infection:_ Anti-HCV * _Chronic disease:_ Anti-HCV * _Immunity_: Anti-HCV * HCV = most common reason for liver transplant in the US * ***_HDV_*** * _Acute infection:_ IgM Anti-HDV * _Chronic disease:_ Anti-HDV * _Immunity_: Anti-HDV * ***_HEV_*** * _Acute infection:_ IgM Anti-HEV * _Chronic disease:_ NONE * _Immunity_: Anti-HEV
45
What are the types of viral Vaccinations?
* ***_Live attenuated_*** * **Conferred Immunity:** Active * IgA, IgG, Tc-cell * **Protection**: Slow onset, longest lasting * Do not give to immunocompromised or pregnant women * **Treated Diseases**: Measles, Mumps, Rubella, Polio (Sabin): oral, Chickenpox, Smallpox * ***_Killed virus_*** * **Conferred Immunity:** Active * IgG * **Protection**: Slow onset, long lasting * **Treated Diseases**: Rabies, Influenza, Polio (salk): injection, Hepatitis A * ***_Purified Viral Protein Subunits_*** * **Conferred Immunity:** Active * **Protection**: Slow onset, long lasting * **Treated Diseases**: Hepatitis B via HBSAg * ***_Preformed antibody_*** * **Conferred Immunity:** Passive * **Protection**: Fast onset, Short life span * **Treated Diseases**: Rabies, Hepatitis B, Shingles * Can be given after exposure
46
What is the antiviral drug ## Footnote **Interferons**
**Interferons** * _Glycoproteins_ that originate from infected host cells to protect other non-infected host cells * _Do not directly affect viruses_, but instead **nonspecifically prevent their replication** within host cells * Block various stages of viral RNA/DNA synthesis * ***_INF-alpha_***: treats chronic hepatitis B and C * Toxicity: neutropenia
47
What are ## Footnote **Bacteriophages (Phages)**
**Bacteriophages (Phages)** * Viruses that infect bacteria cells * Replication can occur by two pathways: * ***_Lytic cycle_***: the process by which some phages _replicate within_ the host cell, producing hundreds of new progeny phage. The host cell is _ultimately destroyed_ * Enterobacteria phage T4: phage that infects E. coli * ***_Lysogenic cycle:_*** The process by which some phages _incorporate their DNA_ in the host cell chromosome. The integrated viral DNA is called a **prophage**. Replication occurs only when the host DNA is damaged, excising the viral DNA. The host cell is usually _not destroyed_
48
What are ## Footnote **Lysogenic conversion**
**_Alteration of the host bacterium to a pathogenic strain_** via expression of the integrated prophage genes. Eg. Corynebacterium diphtheriae producing diphtheria toxin
49
What are: Prions
* ***_Infectious agents composed entirely of protein (no nucleic acid)_*** * Do not elicit inflammatory or antibody responses * Causes **transmissible spongiform encephalopathy**: * Creutzfeldt-Jakob disease (in humans) * Mad cow disease (in cows)
50

NBDE Part 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions