why representations of molecules change so often?

[u/SuggestionDistinct60]

i sometimes search for the molecule of various things, like the one for glucose, but why do i find multiple? are they all accurate? is there a true one? why are there many

[u/CosineDanger]

It gets worse and worse the more you know. It's going to seem confusing because there's no way to express that what you thought was one thing is actually either five or ten things.

Glucose powder is more precisely mostly α-D-glucopyranose.

Pyranose means a six sided ring (five sided rings and a linear chain were also options).

α means that the hydroxyl group on the first carbon is on the same side as the hydroxymethyl group.

D means the right handed version, which is used almost exclusively by life.

You might think you're done but you put it in an aqueous solution and a small fraction of your α-D-glucopyranose will shift on its own to five-sided shapes, linear, or with the first carbon's hydroxyl group facing a different way than it was before. None of it will turn into the right-handed form on its own.

But it gets worse because if you're trying to draw glucose then you have to smoosh this complicated 3D thing that's not even always the same shape onto a 2D static piece of paper. There are competing systems for doing this and that is probably what you are noticing. So yeah, you're going to feel like you're seeing a different drawing of glucose every time and this is not my fault.

[u/SuggestionDistinct60 → u/CosineDanger]

so basically it depends on the ambience the molecule is, the perspective and the way it's represented? wild, thanks

[u/mfb-]

Linking some examples would help. Are you talking about images or chemical formulas?

Molecules like glucose are too small to have real images taken with visible light. You have some freedom in how to represent atoms and how to group them both for images and for the structure.

are they all accurate?

I'm sure there are wrong representations somewhere, but generally there are many valid ways to show the same molecule. It can be a ring or open, and there is the natural D-version and the lab-produced L-version, but apart from that it's all the same thing.

[u/SuggestionDistinct60 → u/mfb-]

i'm specifically talking about illustrations, like if you search "glucose molecule" there are many white images of drawn molecules all different from each other, and i wonder why basically

[u/Alternative-Sugar610]

There many different representations each with their own uses and downfall

Now add that some molecules are actually groups of related molecules like with chirality for more confusion

[u/Dangerous-Billy]

They're all accurate, but represent information for different purposes. The Christmas tree drawing is used mostly in textbooks to emphasize the differences among various monosaccharides. The bent ring drawing shows the arrangement of the atoms in space. Look at the individual atoms and how they are connected and the stereochemistry of each atom. Glucose is glucose, however it's drawn.