Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MED 109- BIOLOGY II > 83. HUMAN IMMUNODEFICIENCY VIRUS (HIV) > Flashcards

83. HUMAN IMMUNODEFICIENCY VIRUS (HIV) Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q
  1. When was HIV discovered?
A
  • in 1981
  • it was isolated in 1983
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. What are the two types of HIV?
A
  1. HIV-1
  2. HIV-2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. What cell in the body does HIV infect?
A
  • it affects the T-helped Lymphocytes (Th-cells)
  • it only affects them because they carry the CD4
    Receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. How does HIV attach itself onto the Host Cell?
A
  • the Viral HIV Glycoprotein attaches itself to the CD4
    Receptor
  • this is found on the surface of the Host’s T-Helper
    Lymphocytes

THE GLYCOPROTEIN OF HIV IS:
- 120 glycoproteins long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. What does HIV cause?
A
  • it causes AIDS
  • this is an Acquired Immuno Deficiency Virus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. What do the T-helper Cells do?
A
  • they activate the B cells to produce antibodies
  • Cytotoxic C-Cells will attack the target cells

IT THE T-HELPER CELLS ARE NOT ACTIVE:
- only pathogens will exist in the host cell’s body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. What are the steps of the HIV Replication Cycle?
A
  1. Attachment
  2. Reverse Transcriptase
  3. Integrase
  4. Translation
  5. Protease
  6. Assembly
  7. New Virus leaves the Host Cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. What happens during: Attachment?
A
  • the virus attached itself the CD4 receptor of the host
    cell
  • this is found on the cell membrane
  • a single RNA genome from the Virus will enter the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. What happens during: Reverse Transcriptase?
A
  • this enzyme will synthesise the virus RNA into DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. What happens during: Intergrase?
A
  • the virus DNA will integrate into the genome of the
    Host Cell
  • Transcription will take place

THIS CONVERTS THE VIRAL DNA AND HOST DNA:
- into a new strand of pathogenic RNA
- this viral RNA leaves the nucleus of the Host Cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. What happens during: Protease?
A
  • Translation will take place
  • a Virus Protein is formed

PROTEASE:
- is an enzyme
- it cuts up the protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. What happens during: Assembly?
A
  • the viral protein fragments will reconstruct
  • they do this by themselves
  • this forms a new virus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. Which enzymes does the Anti-Retroviral Therapy target?
A
  • Reverse Transcriptase
  • Integrase
  • Translation
  • Protease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. What is the most serious pandemic of the 21st Century?
A
  • AIDS
  • 25 million people died
  • 40 million people are infected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. What is the infection rate of AIDS?
A
  • 6 million people are killed per year
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. How long after someone contracts HIV, do they develop AIDS?
A
  • 10 to 15 years after the infection
  • they can be asymptomatic during this period of time
  • this allows them to transmit the disease

PEOPLE WITH HIV WILL START TO DEVELOP AIDS SYMPTOMS:
- when the number of their T-helper cells falls under 200
cells per mm³ of blood

17
Q
  1. How much has Anti-retroviral therapy helped to increase life expectancy?
A
  • it has increased it by 5 to 20 years
  • it allows people to live a life as normal as possible
18
Q
  1. What kind of infections do people with AIDS suffer from?
A
  • they suffer from opportunistic infections
  • this is because they are severely immuno
    compromised
19
Q
  1. What are the main two categories of diseases that AIDS patients will experience?
A
  1. Opportunistic Infections
  2. Malignant Tumours
20
Q
  1. What are some examples of Opportunistic infections?
A
  1. CANDIDIASIS
    - this is a type of yeast
  2. TOXOPLASMOSIS
    - this is a type of protist
  3. PNEUMONIA
    - this is a type of bacteria
21
Q
  1. What are some Malignant Tumours associated with AIDS?
A
  1. KAPOSI SARCOMA
    - this is a malignant tumour
    - it effects the endothelial cells
    - these are found in blood vessels
  2. BURKITT’S LYMPHOMA:
    - this cancer affects the B-cells
    - it results in swollen lymph nodes
22
Q
  1. What are the three ways in which HIV is transmitted?
A
  1. Sexual Intercourse
  2. Blood
  3. Mother to Child
23
Q
  1. How is HIV transmitted through Sexual Intercourse?
A
  • it is transmitted through sperm
  • it is transmitted through vaginal fluids
24
Q
  1. How is HIV transmitted through Blood?
A
  • it is transmitted by sharing infected needles
  • it is transmitted by sharing infected syringes
  • it is transmitted through blood transfusions

WHEN IT COMES TO BLOOD TRANSFUSIONS:
- there is a window period
- where the virus is present in the blood
- but cannot be detected
- it is present in very low levels in the blood
- this is how it is transmitted to other people

25
Q
  1. How is HIV transmitted from Mother to Child?
A
  • it is transmitted during pregnancy
  • it is transmitted during birth
  • it is transmitted through breast feeding

BREAST MILK:
- carries a large amount of then virus in it
- this can infect the child

INFECTED MOTHERS:
- will often have C-sections

26
Q
  1. Can HIV be transmitted through Saliva or Tears?
A
  • no
  • the viral count is far too low for any transmission to
    occur
27
Q
  1. How is HIV detected?
A
  • the virus can be detected in the Blood
  • this happens 3-6 weeks after the suspected infection
    date
  • the detection depends on the method used
28
Q
  1. What are the Diagnostic Methods used for HIV?
A
  1. ELISA
    - this detects anti-HIV antibodies in the blood
    - it can be done 6-8 weeks after infection
    - it is a slower technique
  2. RT-PCR
    - this detects the viral HIV RNA in the blood
    - this can be done 3 weeks after the infection
29
Q
  1. Is there a cure for an HIV Infection?
A
  • no there is not
  • there is no vaccine available
  • this is because HIV mutates at a very high rate
30
Q
  1. What are the Treatment strategies for HIV?
A
  1. HAART
    - this is a High Active Anti-Retroviral Therapy
    - it is a combination of many types of anti-retroviral
    drugs
31
Q
  1. What are the common problems that we find when we use Anti-retroviral therapy?
A
  • toxicity resistance
  • this is because the components of the virus are
    mutating
  • this interferes with the replication cycle of the healthy
    cells in the body and the infected cells
32
Q
  1. What are the three main types of Anti-retroviral Drugs?
A
  1. NUCLEOTIDE ANALOGUES
  2. NON-NUCLEOTIDE ANALOGUES
  3. PROTEASE INHIBITORS
33
Q
  1. What are Nucleotide Analogues?
A
  • they are drugs
  • they inhibit the replication of the RNA in the virus
  • the RNA is incorporated into a growing cDNA chain

EXAMPLE:
- AZT

34
Q
  1. What are Non-nucleotide Analogues?
A
  • they are drugs
  • they inhibit Reverse Transcriptase
  • this enzyme no longer has activity

EXAMPLE:
- SUSTIVA
- NEVIRAPINE

35
Q
  1. What are Protease Inhibitors ?
A
  • they are drugs
  • they inhibit HIV protease

HIV PROTEASE:
- is responsible for the polypeptide cleavage of the virus
- it allows for new virus particles to mature

EXAMPLE:
- SAQUINAVIR
- RITONAVIR

WHEN TREATING HIV:
- it is encouraged to give one medication from each
category

36
Q
  1. What is AZT?
A
  • it is Azido-deoxy-thymidine
  • it is a Nucleotide Analogue Anti-retroviral drug

HOW IT WORKS:
- the next nucleotide cannot be incorporated into the
growing DNA chain
- this is because of the presence of Nitrogen (N₃) instead
of -OH
- this inhibits the replication of the viral RNA

37
Q
  1. Define: HIV Polymorphism.
A
  • HIV has a high rate of mutation
  • new strains will continue to emerge

THE RNA OF THE HIV VIRUS:
- is exposed to the enzyme : Reverse Transcriptase
- this will form copies of HIV DNA (cDNA)

THE REVERSE TRANSCRIPTASE:
- will allow for 1 mutation per HIV genome
- per replicative cycle

MED 109- BIOLOGY II (90 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions