Academic resource library
The free, trusted resources scientists and universities actually use, chosen and explained by VALREXA.
External sites are run by their own organizations. VALREXA is not affiliated with them and receives nothing for these links.
Free textbooks and courses
Rigorous, free learning material from universities and nonprofits.
OpenStax Biology 2e
Free, peer-reviewed college textbook from Rice University. Strong chapters on macromolecules and proteins.
Opens openstax.orgOpenStax Chemistry 2e
Free general chemistry text for the acid–base background behind pKa.
Opens openstax.orgLibreTexts Biochemistry
Open biochemistry textbooks written and adapted by university faculty.
Opens bio.libretexts.orgNCBI Bookshelf
Free online access to biomedical textbooks and reference books from the U.S. National Library of Medicine.
Opens ncbi.nlm.nih.govMIT OpenCourseWare
Free lecture notes, problem sets and exams from MIT biology and chemistry courses.
Opens ocw.mit.eduKhan Academy MCAT
Free videos and practice on biochemistry topics tested on the MCAT.
Opens khanacademy.orgFinding research
Where scientists search the literature.
PubMed
The U.S. National Library of Medicine’s search engine for more than 35 million biomedical citations.
Opens pubmed.ncbi.nlm.nih.govPubMed Central (PMC)
Free full-text archive of biomedical and life sciences articles.
Opens pmc.ncbi.nlm.nih.govGoogle Scholar
Broad academic search across disciplines, with “cited by” links to follow research forward.
Opens scholar.google.comCochrane Library
Systematic reviews that pool evidence on health interventions.
Opens cochranelibrary.comClinicalTrials.gov
Registry of clinical studies around the world, with status and posted results.
Opens clinicaltrials.govbioRxiv
Preprints: new research posted before peer review. Useful, but read with extra caution.
Opens biorxiv.orgMolecular databases
Authoritative data on molecules, proteins and structures.
PubChem
Chemical structures, formulas, properties and literature for millions of compounds (NIH).
Opens pubchem.ncbi.nlm.nih.govUniProt
The reference database of protein sequences and functions.
Opens uniprot.orgRCSB Protein Data Bank
Experimentally determined 3D structures of proteins and nucleic acids.
Opens rcsb.orgPDB-101 Molecule of the Month
Short, illustrated explainers of important molecules. Excellent for students.
Opens pdb101.rcsb.orgAlphaFold Protein Structure Database
AI-predicted structures for over 200 million proteins (Google DeepMind and EMBL-EBI).
Opens alphafold.ebi.ac.ukBRENDA
Comprehensive enzyme database with kinetic data such as Km and kcat.
Opens brenda-enzymes.orgAPD3 Antimicrobial Peptide Database
Curated database of natural antimicrobial peptides such as LL-37.
Opens aps.unmc.eduAnalysis tools
Free tools used in teaching and research labs.
VALREXA peptide calculator
Molecular weight, pI, charge curve and extinction coefficient for any sequence.
On VALREXAExPASy ProtParam
The long-standing SIB tool for computing protein parameters from sequence.
Opens web.expasy.orgNCBI BLAST
Find similar sequences across all known proteins and genes.
Opens blast.ncbi.nlm.nih.govClustal Omega
Align multiple sequences to compare related proteins (EMBL-EBI).
Opens ebi.ac.ukMol* Viewer
View and explore 3D structures from the PDB in your browser.
Opens molstar.orgResearch skills
How to read, judge and cite the literature.
How VALREXA grades evidence
The four evidence levels, from preclinical to approved use.
On VALREXAVideo: How to read the research
Our 55-second guide to evidence levels and red flags.
On VALREXAPubMed User Guide
Official tips for searching PubMed effectively, including filters and MeSH terms.
Opens pubmed.ncbi.nlm.nih.govZotero
Free, open-source reference manager for collecting and citing sources.
Opens zotero.orgBook: How to Read a Paper
Trisha Greenhalgh’s classic guide to judging medical research, on our reading list.
On VALREXAPut your understanding to work
Choose a next step, at your own pace.