Lecture 1 Flashcards
Which statement does not describe the structure of a virus?
Viruses are not living organisms, they do have RNA or DNA nucleic acid core
Why are viruses not considered living organisms? (know the information we discussed on viral replication)
they don’t have a cell membrane and they cant reproduce on their own
Most viruses have an overall structure that is either ___ (rod-like or threadlike) or _______ (a roughly spherical shape). Fill in the blanks.
Helical
isometric
The suitable cells for a particular virus are collectively referred to as its _________.
Host range
What is a bacteriophage?
Virus that only affect bacteria
What is the difference between a T-3/7 or a T-even bacteriophage?
T-3/7 phage - have short tail
T-even phage- a long tail and a very complex base plate
According to the video The Deadliest Being on the Planet Earth – The Bacteriophage, what percent of ocean bacteria are killed by phages every day?
40%
According to the video The Deadliest Being on the Planet Earth – The Bacteriophage, do bacteriophages have specific hosts?
Usually they choose a specific bacteria and maybe one of its close relatives as its host
According to the video The Deadliest Being on the Planet Earth – The Bacteriophage, by what year is it estimated superbugs will kill more people than cancer? How many people are killed by antibiotic resistant bacteria every year approximately?
- By 2050
- 23,000 people
According to the video The Deadliest Being on the Planet Earth – The Bacteriophage, why are we now injecting ourselves with certain viruses? Can bacteriophages hurt your cells?
We can inject them into our bodies to help cure infections. No they can not hurt your cells only bacteria
According to the video The Deadliest Being on the Planet Earth – The Bacteriophage, how was a bacteriophage recently used to cure a disease?
Pseudomonas Aeruginosa the most feared bacteria infected the man’s chest cavity they injected a few thousand phages directly into his chest cavity and after a few weeks the infection have completely disappeared
Which of these is not a step in the lytic cycle (go by the diagram on the PPT)?
Attach, penetrate, synthesis, assembly, and release
Which of these is not a step in the lysogenic cycle (go by the diagram on the PPT)?
Do not immediately kill the cells they infect
What is the difference between a virulent and temperate virus?
Virulent virus- can lead to destruction of cells
Temperate virus- can not unless it turns into a lytic cycle
What is a prophage?
When you have the viral DNA attach to the host DNA
HIV is a retrovirus. What is a retrovirus?
Virus that use RNA
How does the HIV virus compromise your immune system?
Attacks the white blood cells
How does the HIV virus enter a human macrophage?
Directly by HIV infection and indirectly by factors secreted by activated cells in the brain
Once the HIV virus enters your macrophage, it begins using reverse transcriptase. What is reverse transcriptase and what does it do to the HIV virus?
HIV uses reverse transcriptase to convert its RNA into viral DNA
How does the HIV virus (after replication) leave your human cells?
The virus is released from the cell
When a mutation occurs in a certain gene by HIV, the body’s T cells (lymphocytes) become infected with HIV and rupture the cells which lead to the disease called __________.
AIDS
The influenza virus is the most lethal virus in human history. It is an animal-host RNA virus that is distinguished by its protein capsids. __________ is in mammals and birds while __________ and_________ are only found within humans.
Influenza A
Influenza B
Influenza C
Different strains of the influenza virus differ in their protein spikes. What are the functions of these spikes called Hemagglutinin (H) and Neuraminidase (N)?
Hemagglutinin (H)- the virus is gaining access to the cell in interior
Neuraminidase (N)- helps the daughter virus break free of the whole cells once the virus replication has been completed
Why is it difficult to make a proper vaccine for influenza? Why do we have to make a new influenza vaccine every year? (the answer is basically the same for both questions)
The RNA inside of it has a higher mutation rate
What is the definition of an emerging virus?
Originate in one organism and then pass to another and causes disease
Which statement is true regarding the information we discussed about Hantavirus?
Single stranded RNA virus associated with rodents
Which statement is true regarding the information we discussed about the Ebola virus?
Feels like you getting killed in the inside and you do not survive this and it’s a horrible death
Which statement is true regarding the information we discussed about the SARS virus?
Related to the Coronavirus, SARS stands for severe respiratory syndrome
How can some viruses lead to a greater likelihood of certain cancers? (know the examples discussed in lecture)
which is a virus can lead to development of liver cancer because of the damage its keeps on doing
What does the prion that causes transmissible spongiform encephalopathies do to the brain of an infected organism?
The brain develop numerous small cavities as neurons die (looks like your brain has holes)
In our examples discussed in class, how do humans or cows contract prion?
This got infected by cannibals when a human eats or a cow eat the brain it can be contagious
The scientist named Prusiner discovered and named prions in 1982 after reviewing the work of Alper and Griffith (1960s). What exactly are prions?
Proteinaceous infectious particles
What is the definition of a viroid?
They are tiny naked molecules of RNA
Which organisms seem to be most affected by viroids?
plants
How is it theorized viroids replicate?
That there RNA is capable of catalyzing exclusion from DNA
According to the video Viroids – Possibly the Smallest Pathogens on Earth, unlike RNA viruses, the RNA of viroids is not used to make proteins, what is it used for instead? (know the two reasonings the video gives you)
It was just a chunk of RNA or ribonucleic acid
According to the video Viroids – Possibly the Smallest Pathogens on Earth, can viroids infect humans?
No they can not
According to the video Viroids – Possibly the Smallest Pathogens on Earth, although viroids mainly infect plants, why do scientists think they are important to study?
They see them as living fossils
