What are viruses | Cells | Biology | FuseSchool
Summary
TLDRThis video delves into the world of viruses, the most abundant biological entities on Earth, which are microscopic parasites infecting all forms of life. It explains their simple structure, composed of a protein coat and genetic material, and their unique method of reproduction by hijacking host cells. The video highlights common viruses like influenza and HIV, discusses the human immune system's response, and touches on the effectiveness of vaccines and antiviral drugs, while clarifying the ineffectiveness of antibiotics against viral infections.
Takeaways
- π Viruses are the most common biological unit on Earth, outnumbering all other types combined.
- π Viruses are microscopic organisms too small to be seen by the naked eye, much smaller than bacteria and human cells.
- 𧬠They consist of a protein coat surrounding genetic material, which can be either DNA or RNA.
- π€ Some viruses have an envelope that they 'steal' from the host cell's membrane to evade detection.
- π« Viruses are not made up of cells and are considered to be between living organisms and chemicals.
- 𧬠There are different types of viruses, not species, with common examples being influenza and HIV/AIDS.
- π Viruses are parasites that can only reproduce within other living cells, hijacking the host's genetic machinery.
- π€ They cause illness by infecting and eventually killing host cells, leading to the release of more viral particles.
- π The human immune system can often combat viral infections, sometimes preventing entry or destroying the virus after infection.
- π₯ Some viruses have vaccines, like smallpox, which has been eradicated, while others like HIV are more challenging to vaccinate against.
- π Antibiotics are ineffective against viruses and are only for bacterial infections; antiviral drugs exist for some viruses, like HIV.
Q & A
What are viruses and how are they different from other microorganisms?
-Viruses are a type of microorganism that are much smaller than bacteria and about 100 times smaller than human cells. Unlike other organisms, they are not made up of cells and are considered to be halfway between a living organism and a chemical.
What shapes do viruses come in and where can they be found?
-Viruses come in many different shapes and are present wherever there are cells to infect. They are the most common biological unit on earth, outnumbering all other types combined.
Which types of organisms can viruses infect?
-Viruses can infect a wide range of organisms including humans, animals, plants, and even bacteria.
What are the basic components of a virus?
-A virus is made up of a protein coat that surrounds a strand of genetic material, which can be either DNA or RNA. Sometimes, a membrane called an envelope surrounds a virus particle, which is actually stolen from the host cell's membrane.
Why are viruses considered to be non-living?
-Viruses are considered non-living because they cannot reproduce on their own and require a host cell to do so. They lack the cellular structure and metabolic processes that characterize living organisms.
How do viruses cause illness in their hosts?
-Viruses cause illness by being parasites that can only reproduce in other living cells. They anti-host cell, hijack the host's genetic machinery, and produce more virus particles, leading to the death of the host cell and the release of new viral particles to infect more cells.
What are some common types of viruses mentioned in the script?
-Some common types of viruses mentioned in the script include influenza, HIV or AIDS.
How does the human immune system combat viral infections?
-The human immune system can recognize viruses as intruders and destroy them before they gain entry into a cell. Even after infection, the immune system can destroy the virus, leading to recovery.
What are some examples of diseases caused by viruses?
-Examples of diseases caused by viruses include the common cold, influenza, rabies, yellow fever, HIV/AIDS, pneumonia, bird flu, Zika, Ebola, and cancer caused by HPV.
Why are vaccinations important in controlling viral diseases?
-Vaccinations are important as they help in building immunity against viruses, leading to the eradication of some viruses like smallpox. They prevent the spread of viral diseases and protect the population from serious illnesses.
Why are antibiotics ineffective against viruses?
-Antibiotics are ineffective against viruses because they target bacterial infections. Viruses require different treatment approaches, such as antiviral drugs, which can be specifically designed to combat viral infections.
Outlines
π Understanding Viruses
This paragraph introduces viruses as microorganisms that are too small to be seen by the naked eye and are smaller than bacteria and human cells. It explains that viruses come in various shapes and are the most common biological unit on Earth. They can infect humans, animals, plants, and even bacteria. The structure of a virus is described as a protein coat surrounding genetic material, which can be either DNA or RNA. Sometimes, a membrane called an envelope surrounds a virus particle, which is stolen from the host cell's membrane. This strategy helps the virus evade detection by the host. The paragraph also clarifies that viruses are not living organisms but are somewhere between living organisms and chemicals, and they reproduce by hijacking the host's genetic machinery.
π¦ Virus Infection and Impact
This paragraph delves into how viruses cause illness by being parasites that can only reproduce in living cells. They infect host cells, hijack their genetic machinery to produce more virus particles, and eventually cause the host cell to die, releasing new viral particles to infect more cells. The paragraph also discusses the two different ways viruses attack host cells, which will be detailed further in the video. It highlights that viruses cause many human diseases, including the flu, rabies, yellow fever, HIV/AIDS, pneumonia, bird flu, Zika, Ebola, and HPV. The human immune system is capable of dealing with viral infections, sometimes destroying the virus before it gains entry into a cell or recovering after infection. However, in some cases, the immune system may not be able to destroy the virus quickly enough, leading to permanent damage or death. The 1918 Spanish flu is mentioned as an example of a deadly viral outbreak.
π Vaccines and Antiviral Drugs
This paragraph discusses the development of vaccines against viruses, which has led to the eradication of some viruses like smallpox. It also mentions that some viruses, such as HIV, have proven impossible to develop vaccines for. The paragraph clarifies that antibiotics are ineffective against viruses and are only useful for bacterial infections. It highlights the existence of antiviral drugs, such as those that prolong the lives of people affected by HIV. The paragraph concludes by emphasizing the simplicity and effectiveness of viruses in causing infections and encourages viewers to like the video, subscribe, comment, and check out the mentioned app for more information.
Mindmap
Keywords
π‘Viruses
π‘Protein coat
π‘Genetic material
π‘Envelope
π‘Parasites
π‘Influenza
π‘HIV/AIDS
π‘Immune system
π‘Vaccinations
π‘Antibiotics
π‘Antiviral drugs
Highlights
Viruses are the most common biological unit on earth, outnumbering all other types combined.
Viruses are smaller than bacteria and about 100 times smaller than human cells.
They come in various shapes and are present wherever there are cells to infect.
Viruses can infect not only humans but also animals, plants, and even bacteria.
A virus is composed of a protein coat surrounding genetic material, which can be either DNA or RNA.
Some viruses are enveloped by a membrane stolen from the host cell, making them harder to detect.
Viruses are not living organisms but exist between living and chemical states.
Different types of viruses exist, such as influenza and HIV/AIDS, rather than different species.
Viruses cause illness by parasitizing host cells and hijacking their genetic machinery to reproduce.
The released viral particles from a dying host cell can infect more cells and spread to other individuals.
There are two distinct ways viruses can attack host cells, detailed further in the video.
Viruses cause a wide range of human diseases, including the flu, rabies, yellow fever, HIV/AIDS, and Ebola.
The human immune system is capable of recognizing and destroying viruses, preventing infection.
In some cases, the immune system may not be able to destroy the virus quickly enough, leading to permanent damage or death.
The Spanish flu of 1918 is estimated to have caused up to 50 million deaths worldwide.
Vaccinations have been developed against many viruses, contributing to the eradication of some, like smallpox.
Some viruses, such as HIV, have proven impossible to vaccinate against.
Antibiotics are ineffective against viruses and are only useful for bacterial infections.
Antiviral drugs have been developed to combat certain viruses, such as HIV.
Viruses, though simple, are highly effective at causing infections.
Transcripts
[Music]
in this video we're going to look at
what viruses are
viruses are type of microorganism they
are too small to be seen by the naked
eye much smaller than bacteria and about
100 times smaller than human cells
they come in many different shapes and
are present wherever they are cells to
infect in fact
viruses are the most common biological
unit on earth outnumbering all other
types combined
viruses can infect humans all animals
plants and even bacteria
viruses are very simple
they are made up of a protein coat
surrounding a strand of genetic material
the genetic material can either be dna
or rna
sometimes a membrane called an envelope
surrounds a virus particle
this envelope isn't made by the virus
but is actually stolen from the membrane
of the host cell
this is a great strategy by the virus it
makes it harder for the host cell to
identify the virus as foreign
as we just saw
viruses aren't made up of cells in fact
they aren't really living
they are halfway between a living
organism and a chemical
because they aren't living we say there
are different types of virus rather than
saying different species of virus some
common types of viruses are influenza
and hiv or aids
so viruses aren't living how do they
cause illness
viruses are parasites they can only
reproduce in other living cells they
anti-host cell and hijack the host's
genetic machinery
they make copies of their own viral
genetic material instead and produce
lots more virus particles
after lots of virus particles have been
made the host cell dies and the viral
particles are released to infect more
cells the released viral particles can
also spread to other people
there are actually two different ways in
which virus attacks the host cell which
we'll look at in more detail in this
video
viruses cause many human diseases
including skulls influenza rabies yellow
fever hivo aids pneumonia bird flu zika
ebola and the cancer causing hpv there
are just a few examples
fortunately the human immune system is
very good at dealing with viral invaders
sometimes our immune system will
recognize the virus as an intruder and
will destroy the virus before it gains
entry into a cell
even after the infection begins our
immune system destroys the virus and the
person recovers
sometimes the immune system cannot
destroy the bias fast enough
and the virus can cause permanent damage
or death
in 1918 the spanish flu is thought to
have caused up to 50 million deaths
worldwide
scientists have developed vaccinations
against lots of viruses which have even
led to the eradication of some viruses
like smallpox as human hosts become
immune
however some viruses like hiv have
proved impossible to develop any kind of
vaccine for
did you know that antibiotics do not
work for viruses
they are only for bacterial infections
if you have a cold or flu you shouldn't
be taking antibiotics that won't make
any difference
there are some antiviral drugs that have
been developed such as the one that
dramatically prolongs the life of people
affected by hiv
so there we have viruses
they're incredibly simple organisms but
are extremely effective at causing
infection
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up and don't forget to subscribe comment
below if you have any questions why not
check out our fusco app as well
until next time
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