Life-like texture of paint
My boyfriend and I just got into a surprisingly heated debate on this. He was wondering why a scientist couldn’t simply create a living being from the elemental level, molecule by molecule and cell by cell. Neither of us are particularly well versed in biology (that much is probably obvious) but my understanding is that any type of genetic modification that is technologically possible requires some existing piece of genetic material, and that “ building” a DNA code from scratch is orders more advanced than what is currently possible. Hopefully this makes sense and I thank you in advance for your help!
nitrochemist: A cell in itself is insanely complex. If a carbon atom is the size of a pingpong ball then an average cell would be the size of a large city in diameter. It is also as complex, regulating what enters and exits as well as creating and modifying molecules, performing a specialist task and if its a part of an organism, communicating with other cells and tissues as well as receiving information and reacting accordingly.
This is one cell. Trying to get billions/trillions to form a functioning organism with organ systems etc. is even more difficult than trying to build something as complex as a city in a jelly blob smaller than the diameter of your hair.
Tldr: life is far more complex than you’d think.
Kotama: This is called abiogenesis, and it is currently the biggest mystery in the field of cell biology. We can create semi-synthetic organisms (https://www.nature.com/articles/nature13314), but as of yet are unable to create completely synthetic organisms due to the problems that abiogenesis has thrown at us.
Scientists are actively researching and pursuing this particular problem, as it is currently the last major barrier in the way of creating completely synthetic organisms with expanded DNA/RNA alphabets as well as having an extremely important role in genetic modification and other medical research fields.
jasoba: Here are some nice yt clips about abigoenesis…
thetreece: Even creating a drug from scratch to interact at specific receptor is insanely hard. It requires years of research, millions and millions of dollars, and thousands upon thousands of man-hours. And that’s just a single molecule. There is an insane number of unique molecules like this inside a cell, in an insane number of configurations. Also, they don’t sit still like you’re building a house out of bricks. Bonds are constantly forming and breaking, new compounds being formed all the time. A cell is a sea of active processes, many of which (hell, MOST of which), we don’t fully understand.
Building a cell “molecule by molecule” is like trying to build a functioning copy of the World Trade Center (complete with all the furnishings), using nothing but tap water as building materials and chop sticks as your own only tools. We are so far away from this that is might as well be science fiction.
If we were to achieve abiogenesis, it would be by dumping a bunch of naturally occurring compounds in a jar, adding energy in the form of heat and light, giving it a good shake, and hoping some shit happens eventually.
Watch the first half of this video for an idea of the scale of the shit we’re talking about.
Making specific strips of DNA or RNA is one thing. Building a cell from scratch is completely different.
aphasic: Ask your boyfriend why he doesn’t make an iphone from scratch, from just elemental molecules with no tools or other modern technology he doesn’t build himself. It’s effectively impossible, until you have built the complete infrastructure of an industrial society to build new pieces of the infrastructure of an industrial society.
The problem is essentially the same for making cells. Basically, cells are made of machines so tiny we can’t effectively build them using any technology we have, except cells themselves. It’s almost like they are impossibly advanced alien iPhones that fell from the sky. We can understand some of what they do. We can play around and change the code some. But we can’t build them from scratch with the tech we have right now.
We can write DNA instructions using just chemistry, but in order to convert from DNA to RNA and then proteins, we need the machinery that does that process, which is itself made of RNA and proteins. It’s like trying to make an egg without a chicken, or a chicken without an egg.
htbdt: DNA synthesis isn’t that difficult, machines exist to do this, mainly to make PCR primers. Little copies of the starting and ending place you want to get out of the larger piece of DNA and allow the polymerase to keep copying that smaller piece you want.
Technically, an organism has been created using artificial DNA but it was the most simple organism they could do and the procedure was not simple at all.
News report of study:
Actual study: https://www.nature.com/articles/nature13314
m4risa: It’s mind boggling complex. Think of it this way. Lets say you wanted to make a cell part “A”. You both realise how insanely difficult it is to make A. Now picture you have A and thousands of other similarly complex systems in a subsection of a cell, and hundreds of that in a section of the cell, etc. It’s unimaginably difficult. Check out the coagulation cascade in humans. It’s so perfect and intricate and well designed and beautiful that it literally brought a tear to my eye. And to think that this is only ONE of the millions of quirks our body has..
Also the fact that by going micromolecular, your tools that you use to construct the constituent molecules inadvertently react with them. Today’s technology is far from being capable of achieving what you state.
Interestingly, building a DNA code from scratch isn’t difficult. It’s being done on a small scale for things like protein manufacturing (check out artificial insulin). In reality it’s far from just nucleic acids like DNA or RNA. You need lipids (bilayer, storage, steroid messenger) proteins (bulk of the requirements) carbohydrates sugars polymers and copolymers messenger molecules gasses metal ions minerals. All these only from the back of my head. Above all of these, they must interact with each other perfectly.
JasontheFuzz: For a more ELI5 answer, he’s basically asking why we can’t 3D print a living creature. You can ask Dr. Frankenstein why that’s a bad idea.