Specifically looking for DNA, Testosterone(Other Steroids...), THC(Drugs...), Protein(...), and Sugar(!!!.) I've found a few search engines I was even hoping would produce meshes, but not even any static images yet. Doing a report for Science Class!

Attached Link: http://www.chem.sunysb.edu/msl/chemray/alpha/

There is a DNA short strand at Runtime DNA, in the freebies. A for the others, you may have a hard time finding something for "protein", since it is a generic name that ecompasses billions of molecules. Testosterone is not that complicated to model, but beware of "other steroids" : there are suite a few variations ! Here is a link to spatial representation of some molecules. Hope this helps.

The page in the above link is about a program which can design the molecule in 3D view.

I don't remember who made them but there was a library of Bryce models in www.3dcommune.com of various amino acids, compounds like nicotine and simple atoms...

I was a chem major and am a forensic science grad so I can emphasize. Do the structures need to be 3d? If you need to just draw structures, then try downloading ISIS draw. Maybe there is a version of chemsketch freeware at acdlabs.com that is 3d. If you need 3d structures, see if your chem dept has Chem 3d Pro. I think there is a makemol program in the freestuff here, but I've never used it. What is the assignment? Do you need meshes or just images? Also, I did my seminar last semester on anabolic steroids so if you want my powerpoint I can send it to you.

I used to have a freeware molecular modeling program that would output .obj files I could use in Poser but I lost it and don't remember the name. If you can live with 2D images, here is a link to BioDesigner which is overkill but easy enough to use. It will open a number of formats, including .pdb (protein data bank). There are loads of sites on the web to download .pdb files (NIH is one). Try typing the molecule you're looking for and pdb in Google. That's how I found this model of Cholesterol. Be warned, there are tons of analogues and variations so you better have a bit of knowledge about what you're looking for - way too many years since I studied biology :-) http://www.pirx.com/biodesigner/index.shtml

The assignment is to correctly 5 molecules, with as much detail as possible. Those are the ones I picked. If this comes out nice I may print and hang some around my apartment.

Attached Link: http://molvis.sdsc.edu/visres/index.html#pdb

Some sources for pdb files.