DNA. What is it made of? How does it makes us what we are? How and why do we share the same DNA with animals, plants, fruits, etc. ?


DNA. What is it made of? How does it makes us what we are? How and why do we share the same DNA with animals, plants, fruits, etc. ?

In: Biology

Nucleotides of Cytosine (C), Guanine (G), Adenine (A), or Thymine (T) work like letters of a code to build up information on a strand of DNA and DNA replicates using precise pairing of these nucleotides to avoid making mistakes. https://youtu.be/rJFP2IRnzjk

Lots to unpack here.

DNA Stands for deoxribonucleic acids, it’s composed four molecules, Adenine, Guanine, Thymine and Cytosine. Arrangements of these molecules determines what protein is made, for example ACTGACTGA…. May encode for protein x while GCTGATCTA… may encode for protein y. The ordering of these base pairs are your genotype, when they are translated into protein you get your phenotype or basically the function purpose of that price of DNA, it does get really complicated with stuff like Exxon’s or introns and splicing regions and that the same dna can translate to different proteins because of splicing etc. but just keep it simple. DNA encodes proteins through its 4 molecules that I listed above. Each three bases encodes an amino acid, a chain of amino acid produces a peptide or a protein which is used for some cellular function, such an enzyme which metabolizes sugar.

How does this make us who we are?
Well everyone in the same species basically has basically indentical dna composition to keep it simple, there are slight difference causes certain differences, certain genes may have different alleles which are slight mutations in gene that perform the same function like with blood type or eye color.

How do we all share the same dna…
Well a current theory asserts we all derived from a common single felled ancestor so in many ways, every living thing in earth derived from a single organism with a single set of dna/rna and so we are all related. Obviously things have changed over time, thus is the theory of evolution.

Well for the second half of the question, I like to give analogies. A relatively simple explanation is to think of legos! With the same basic blocks, you can build pretty much any structure. The reason is because the blocks can combine in many ways in 3-dimensional space.

The same is true for DNA: despite being only 4 basic blocks (CGAT), they combine to create a set of amino acids. And those amino acids combine to create proteins. And those proteins are folded in different 3-dimensional structures that can perform different roles. It becomes very complicated as it keeps going until you get a full human versus a full seagull.

The reason for the complexity of these molecules is like chemistry/physics: even though hydrogen and aluminum are made of the same basic blocks (protons, neutrons, electrons), they behave very differently because of their structure and the physical laws that govern the universe.

Basicly, DNA acts like a blueprint for making things like protein, which in turn act as structures of cells or help the body do the chemical processes it needs to do to function.

Imagine DNA like a zipper. When it’s closed, it can’t be read, but it’s all twisted up which keeps it nice and small.

RNA Polymerase is a molecule that reads the DNA and translates it into information that other molecules can use to know how to make a protein and what protein to make.

Polymerase basicly is the thing that zips/unzips the zipper. But unlike a normal zipper, it takes in the 2 sides of DNA and has another outlet where new translations of the DNA come out, this way the DNA is saved so it can be read later.

The zipper goes up, opens the DNA as it goes and closes behind it as it moves up.

As it’s going, it matches 1 side of the DNA zipper with matching opposite nucleotides.

The extra strand this polymerase makes I RNA.

This RNA strand can be used for many things. It may be used to make proteins or it may be a transfer RNA molecule that helps build the protein using other structures like the ribosome to mediate them.

So after all the parts are made, you have some RNA strands that act as **instructions** and some small strands called *tRNA that act as carriers*. The tRNA carries peptides which is what proteins are made of.

These 2 parts enter the ribosome which connects the 2 in the right order by connectinf the sequence of instruction RNA to the matching tRNA, which then let’s go of it’s peptide to form a chain with the other peptides that other tRNA have left.

As you can see, the DNA contains the important information that other parts of your cells use to put together proteins and other building blocks of your body. It all gets put together to form larger and larger structures and to make the parts that do other things the cell needs to do.

Trying to really simplify here; this is some really big concepts at such a micro-level that most five year olds wouldn’t really ever get it.

So DNA is made up of a sort of code, and each combination of three “letters” of that code translate to a different building block. Your DNA is made of two halves that fit together kind of like a zipper. When it’s time to read that DNA, it gets unzipped, which reveals the code inside. Then those building blocks that go with each three-letter combo line up and fold together to make proteins or hormones or whatever is being made. Then the DNA gets zipped back up until the next time it’s being read.

Most DNA is code for things that a lot of living things share. That’s why a lot of DNA is the same throughout most animals. Every mammal on the planet has blood, for example, and a lot of the parts to make mammal blood cells are very similar, so it makes sense the DNA that codes for those parts is also similar.

To answer your last question… lots and lots and lots of our DNA is just to make each cell. Like, most of our DNA. In fact, single-celled life evolved for about *1 billion years* before the first multicellular… anything appeared. That’s 1 billion years of evolution just to get individual cells to function on a complex level. Once you have those cells, you can build them into any shape pretty easily.

So, a human and a lizard both have muscles and bones and blood and neurons and nerves that are all very similar… every cell of every animal has the same set of organs, gets energy from fuel and oxygen in the same way, and has a cell wall made of the same stuff… even between you and a banana there’s a ton of shared DNA that’s all wrapped up in some basic functioning of individual cells.

DNA or Deoxyribonucleic Acid, is an extremely complex molecule made up of 4 proteins (often called nucleotides), Adenine, Thymine, Guanine, and Cytosine. When sequencing DNA we write it as a sequence of the first letter of these, for example:

DNA is stored in the nucleus of a cell and is used to encode for proteins our cells and the cells of other organisms need to function. It is sent as mRNA (Messenger RNA) which is basically one half of a chain of DNA to a ribosome which creates the proteins.

Depending on what proteins your specific DNA codes for, you may look different, these can effect skin tone, eye color, hair color, how much hair you have etc.

We share a lot of DNA with animals and plants because those encode for the proteins every living organism needs, like ATP, the protein cells burn for energy

>DNA. What is it made of?

The other commenters have answered this, but if you have any follow up questions, do not be afraid to ask!

>How does it makes us what we are?

For more information, this process is known as transcription and translation. If you do an internet search for “transcription and translation for students,” you will find tons of helpful results. [Here’s one video.](https://www.youtube.com/watch?v=bKIpDtJdK8Q) [Here is one page of text with pictures.](https://www.atdbio.com/content/14/Transcription-Translation-and-Replication)

Imagine DNA is like a recipe book, and the food made based on the recipe is you. The DNA doesn’t actually *do* anything, it is a template. Reading and carrying out the template/recipe is transcription and translation.

>How and why do we share the same DNA with animals, plants, fruits, etc. ?

Life on Earth is all made of the same types of molecules, broadly speaking. Not *exactly* the same, but we’re all made of similar enough stuff that, for example, you can eat animals, plants, and fruits, your body breaks down their molecules into smaller pieces, and then can stick those pieces together to make more molecules for your own body. So for instance, DNA gets broken down into [the individual nucleic acids.](https://www.genome.gov/sites/default/files/tg/en/illustration/nucleotide.jpg) Proteins get broken down into [individual amino acids.](https://beautiflworid.com/wp-content/uploads/2019/04/Protein-amino-acids-1024×376.png) Plant molecules and human molecules are both made of the same basic parts, just in a different order. Similar to a chapter book for children and a big boring textbook both using all the same letters.

Regarding the sharing DNA with animals and planta and fruits:

If we think of DNA as the building blocks of life; we can actually observe we share many characteristics with many living things.

Moves around with muscles and bones in a general shape of a torso with a back spine, has 2 legs and 2 arms.

Breathes oxygen from air and exhales CO2 through the nose.

Has blood, a heart, veins and arteries.

Has a brain in the head, feeds by the mouth and defecates through the tush, has eyes that adapt to different light conditions, and so on.

As you can see all of those things are shared with MANY species so all of those could be similarities in the gene code.

Even if you said “but giraffes have such a long neck”. Fair, difference. But it’s the length; aside from a few much needed adaptations regarding the operation of such a long neck, it’s “just” a really long beck.

In the end, we are not too different from what sone people refer to as “non-human” animals; and our DNA shows it.

We share most of our DNA with almost every living being for two main reasons.

First: We all living beings basically come from the same root. So, if all started for example from individual number 0, the resulting (evolving) descendents have the 0 on it.
Being for example 01, 02, 03

0 is a unicelular organism, and 1 is a animal, 2 is a fungus, and 3 is a plant (this is a very rough example)

So fast forward to the future.

013 is a human
011 is a Dolphin
034 is a Corn
027 is candida albicans
And so and so

So in that example you share 33 percent of your DNA with a dolphin an with a corn and with a fungus, just because at the very beginning we were the same.

The second reason of sharing a big amount of DNA with every living being is that most of the DNA is “Trash” DNA, that means that is DNA that doesn’t do anything.

For example, human may be: 01827491013828759274939

And just 013 is functional, the rest of the numbers are just that, and given that in DNA language there are just 4 letters the probability of having repeated patterns are bigger.

I hope this helps a little bit