anyone here because of CORONAVIRUS?

This is an easy to understand introduction to this famous question, nicely done! I lean more toward the opinion offered by one of my former professors: Life is a term for poets and philosophers, not scientists. The philosophical question is a fun one, but from a scientific point of view maybe we're better off focusing on the chemistry and evolution of replicators instead of trying to distill some list of traits that will cover the whole bunch. And viruses are certainly evolving replicators that undergo biological chemistry…

I'm afraid I don't see how your two-phase explanation answers the question. A cell is alive whether or not it's infected with a virus. The addition of virus particles doesn't make it any more or less alive (until the virus kills the cell). That doesn't really say anything about whether the virus is alive. You could just as well say that salt is not alive, but a cell containing salt is alive, so salt is a two-phase living organism. Which makes this concept far too broad to be a definition of what is alive, in my opinion.

That was so well explained, thank you

But would a pallet full of toilet paper protect me from viruses ?

IT dies though. After being washed in hot water. So it must be alive first. Surely? If it’s not alive, it can never really be destroyed, I’m guessing.

It would appear that I'm not a lifeform. I'm having a hard time reproducing. 😅

Oh my goodness. I'm 65 year old and I completely understood this. Thank you so very much!

This channel is so cool and clarifying. Thank you Prof. Racaniello for making these vids.

Where did virus come from

If in the particular stage the virus is said not to be alive then how does the virus sustain itself outside of the cell for varying amount of time on different surfaces.? Did we fall short on our definition of what constitutes a cell, the outer casing in which the RNA is housed , what is it called, what's it made off? ...JUST BEING INQUISITIVE...

Can Viruses be analogy to Seeds. Are seeds Alive?

Than my question is: how do viruses "live" on inanimate objects for hours or days?

i think the virus is alive but waiting in hibernation to enter the cell

Computer viruses are very analogous. They cannot be "alive" without a computer to run them.

Viruses are not alive.

But how viruses know that needs cells to duplicate??how viruses know the path to invade cells?And viruses have brain to think?too many questions with out answers

It’s fascinating that something that can act of it’s own accord on its environment is not alive. Simply fascinating.

Summed up: Viruses aren't alive Cells are. Note this video made it seem like cells are only alive woth viruses in them which isn't true but I'll give it a pass bevause I know better

No they’re not. Saved you five-minutes.

Speaking as a professional armchair biologist I completely disagree, or rather I think the parameters for what constitutes "life" are arbitrary. Whether or not it has a cell, whether or not it makes energy, whether or not it grows, the means through which the virus produces more of itself or the means (or lack thereof) it has to interact with its environment are irrelevant as far as I'm concerned, the only thing that matters to me is can it reproduce and can it evolve, and the answer to those are yes, the fact that its method of doing so is as an obligate intercellular parasite is again, irrelevant. To my mind viruses are some of the simplest forms of life possible, and I spit on any trained professional who's studied the topic for years who disagrees with me. So there!

I keep hearing the experts saying that viruses aren't living things, they just need a host to survive and reproduce; AND that they survive for a certain amount of time on certain surfaces. Doesn't saying survive and reproducing imply something living? Another question: If they aren't alive, are they programmed to do what they do? If so, who is programming them and what purpose?

thats like saying sperm isnt alive til it meets the egg

If a viral particle is alive then a PCR mix is also alive, since it exhibits replication and sometimes a mutation

Ur video helped me really understand what a virus is. Thank u so much.! 👍♥️

If I accidentally shoot myself in the head with a nail gun, and the nail hits the creative part of my brain and somehow makes me want to make carpenter nails for a living, is that nail considered alive then?

Vincent, you must expand your concept of 'life'. You would consider an obligate parasite WORM a life form would you not??

How did a virus particle(not infected cell) exist if it wasn't alive. Like the potential to infect and replicate is a living property right?

Life is a symphony, a party, a dance of different various molecules. A virus is alone, it doesn't do what cells do, it doesn't produce what cells produce. If you take a step back and try to realise, if you could hear the molecules of cells, a virus doesn't create this symphony or dance. Also cells have a baby stage and a mature stage, all living things do, living things breathe or exchange, inhale, exhale, or excreate, living things are uniquely reliant on water, require water in one way or another. Maybe start there. Instead of using linear thinking and what is only visible to define life.

It’s like a computer program. No good without an operating system.

If virus is dead particle, exactly what happens when a dead virus cell attaches to living cell? How a dead thing enter a living thing?

If not alive...then how can it respond to release RNA ?

So how was the first of any particular virus particle created then?

Then why do people say viruses can live in the air for 10 minutes? If viruses aren't living at all?

With these conditions I'm not even alive.

I have enjoyed your virology lectures and posts, wonderful and accessible! Keep sharing your great gift for teaching and supporting online access to science. Thank you.

Something doesnt need to be a lifeform to replicate itself. If you lit a fire on candle, you’d only get a little fire, now you lit that fire in candle on bushes , it will produce a bigger fire. Does that mean a "fire" is a life form? no

I am a big fan of twiv and twim. However, to state that living things are required to make energy seems to violate the laws of physics. Perhaps it should be phrased "make use of or convert/store energy?"

something that's not a living thing knows what to do when it enters a host. please explain

How does something dead take over something that's alive?

If it isn't alive before coming in contact with cells, why there is time period like aerosols for up to three hours, up to four hours on copper, up to 24 hours on cardboard and up to two to three days on plastic and stainless steel ?

So, viruses are not alive. Got it.

Great video!!! Me and my classmates really made good use of this video. Thank you Vincent.

If one raises the question 'Are viruses alive', one has to look for the right definition of life and living systems.

In the debate over living vs not, if anything will be alive then calling it a seed or parasite is trivial to what it will become. How it evolved is still more interesting.

3:00 He defines a virus as an organism with two phases..... organism..... as someone wrote in another comment this question is better left for poets and philosophers. Racaniello struck out in this video, imho...

totalmente de acuerdo con su conclusión. Muchas gracias por hacer estos vídeos.

To say that something is not alive because it needs some action to reproduce makes about as much sense as a woman is not alive because she needs some action to reproduce. 3:22

Switch "evolve" to adapt.

The cell is alive, the virus is not. The virus is just a set of programs in the cell that is alive. The cell produces the new viruses, the virus does not. The virus in the cell is still not alive. The cell is doing everything. It reads the instructions from the virus and carries out the function, which is to make many copies of the original. Saying the virus is alive in a cell would be like saying a computer program becomes alive in a computer if that program was to copy itself many times. 😂

I understand the debate and also this type of explanation. To me, this explanation seems like an analogy for a spore/seed-plant mechanism; a seed in itself is not alive, but with the right conditions it becomes alive. Of course, there are more questions; for example, if the cell eventually dies, then, why the mechanism? Reading other explanations, I thought about the virus as a defense mechanism or a poisonous protein; could these apply?

Is a seed "alive"?

Hi, this is a remarkable video. I have read the book by Addy Pros "What's Life" and I think he made very nice points there. The concept of DKS is a very important concept to consider if we are to tackle this question. Watching your video,I became confused as to how a non-living structure like the virus particle goes around infecting cells or, for that matter, doing any thing ..? .. I think viruses are not just dead. .. :)

I think it's better to think of a virus as active and inactive. I had chickenpox as a child which was an active viral infection. I recovered and had no more symptoms but we know chickenpox can come back as shingles so between the time of recovery and shingles the virus is inactive not dead.

This is finally answers my understanding on what is virus vs bacteria, thank you!

so how does the original virus, come to be ????

The first criteria you set for life is a non sequitur. By saying one or more, you encompass all cells, and a cell is just another word for box, cubicle, enclousre, and so on. the point about evolving is also subject to scrutiny in my book, because changing form doesn't require volition, as in consciousness. This happens to molecules all the time, and it's because of electricity. You could say that electrons are living beings by that criteria. How can you call it an organism when it doesn't meet any of your own criteria set for life? That's criminally negligent. It seems to me that cells eat these protein capsules for the protein, and then get dissolved, or not, by the acid, RNA, which is inside of the ... virus, exosome, particle, whatever you want to call these multituduous, if that's a word, particles, and that this only occurs if the acid inside of this semi-biotic thingy is potent enough to dissolve an entire cell. I don't think that drinking bleach is good for you, and, I, likewise, recognize that an alkaline environment in a living thing is more robust to tackle outside influence, as is proved by the fact that most plants are alkaline, and meats acidic - plants can withstand attacks from microorganisms to a much greater degree because of having a hard outer shell, and the ability to withdraw water and nutrition from soil, which is absolutely teeming with microorganisms.

It has helped me a lot to understand about virus. Thank you sir!

You need to change your wording. The cell is infected due to poison and toxins NOT a virus. You are correct viruses are not alive, but then you say in the cell they are alive -how on earth did it get into the cell if it’s not alive and doesn’t exist. What really happened is toxins caused the cells to get infected. Simple. Also, you should state that viruses are NOT contagious.

A virus needs a host called Cell, humans need a host called Planet. The write definition is: Is a virus alive from our point of view? No. Is a virus alive from an objective point of view: Yes and No, as everything.

That's like saying, a ghost isnt alive but a person possessed by a ghost is

Thanks for posting this! I found it helpful

Hand up!: I saw that a frequency can kill a cancer cell, is that possible for viruses as well?

If it can die then its alive.

Playback speed 1.25x

Alive is taken over by the dead at a most basic level.

How does a virus re-program a cell? This is quite sophisticated if you ask me. Virus are intelligent.

I start to think our definition of lifeform have some problem and need to modify. The current definition was made as we lack of some knowledge by far we have understood. Virus might be the key to understand the real meaning between lifeform and inanimate things. Though it lack of many basic lifeform definition, it clearly evolve/mutates to suit the new environment and know how could find best place for survival. If it just non-living thing it won’t evolve from animal infection to another different host

But doesn't genetic makeup that can be duplicated, replicated, and infect other organisms, be a significant part of a life cycle? If it does and can cease to exist, or "die off", then how is that not considered to being a life, alive?

I guess seeds aren't alive by that logic

How something which isnt alive, or produced in human body, can make us sick???

o am more confused now since the difinition of life has been established which leaves a big portion of nature as dead! Can life exist without viruses? NO!

When someone gets catches a virus are they catching just the virus or the virus infected cell?

Uh huh, you know what it is Racaniello Racaniello Racaniello Racaniello Yeah uh huh, you know what it is Racaniello Racaniello Racaniello Racaniello

I am not a scientist or a doctor. But i think it makes our cell like zombie.

Hello! Today is my first day as a pre-med student!

The answer. No. The whole contagion theory is a con

Once it enters the cell, its genome does not encompass 99% of the infected cell's proteins, so your answer is abysmal in that viruses are obviously and permanently nonliving bimolecular constructs.

I don’t like this two-phased explanation cause a “virus infected cell” being alive is not the same thing as the physical virus itself being alive. that’s like asking is my severed head alive vs. my head when attached to my body. Two entirely different questions!

I am sorry to strike so low but dang thats a nice shirt! I really miss those Nordstrom boat shirts.. good taste..

Not quite... what you've explained could easily be the phases of human embryo, while in utero is considered alive.

How do they live on surfaces if they are dead outside of hosts?

My issue with viruses is I have never seen actual convincing evidence that they exist. I would love to see some real science that demonstrates the existence of viruses. This video is nothing but theory. And what I find creepy is there is nothing on KZfaq about viruses that scientifically shows me that viruses are real.

good thing about that virus is it would hard to inhale or ingest LOL

In some ways whether something is alive is irrelevant. What matters is the practical issues-how it affects organisms. We can say a virus is a biological machine.

Look it's an interesting question.,..how long can a virus exist outside a host,..,and inside a cell it behaves like regular organic material,,...in fact looks and behaves and engages like regular biomechical systems..it's like asking the question ..what is electricity...

now it makes sense why computer viruses are called so, and not computer bacteria.

So how does the dead virus enter the cells of a person?

I go to Penn state and this was way more useful than my 2 fucking hours of lecture

Hi, so I have question about viruses. Do viruses need energy for certain things, if yes where do they get this energy from and why can't they generate their own energy? Senna

I really like your definition. So simple so deep. Drawing a distinction between VIRUS and "VIRUS INFECTED CELL". Would you like to comment on thinking of viruses as CELL'S MESSAGES? Therefore the argue of whether virus is alive of dead drop automatically.

Are the Novel corona virus is alive and that's is true when a people is stay inside the home for two week as a result there is no human in streets or markets and the novel corona virus is no host cell and then the NCV are controlled or died plz reply must??

It does not have a cell, no life so why it is an microorganism? I do not think it is

Wow, thank you for your insight.

How does the virus survive outside the host ?

So, could a virus be similar to a plant seed or a pollin in some ways? What is the best method of destroying a virus so that it cannot function and cause infection? Certainly they cannot be indestructible.

Short answer: no Long answer: also no

Great! This is the better answer for this question I ever see

Explained very well. Thank you!

The world has a channel like this about us lmfao