Version 1.0 · Coming to the App Store
Make a peptide bond.Then break it.
Glycine's carboxyl carbon meets alanine's amino nitrogen and a water leaves. Hydrolysis runs the same path backwards.
An offline quiz and reference for the 20 amino acids, in 2D and 3D, for MCAT and biochemistry students.
Coming to the App Store for iPhone, iPad and Mac.
Questions before launch: support@silkway.studio
Tap an atom. It lights in both views.
Each of the 20 has a 2D drawing and a 3D model side by side. Tap an atom in one and the same atom lights in the other. A toggle switches the neutral form to the zwitterion.
On every card
- Codes
- Three-letter and one-letter
- Side-chain class
- From Lehninger's classification
- Codons
- Every codon that encodes it
- Formula and mass
- Average mass in g/mol
- pKa and pI
- With their textbook source
Seven chapters and 21 kinds of question
Three chapters are free, with unlimited quizzes and no ads. Pro opens the other four and MCAT mode: timed, mixed questions with no hints until the end. The Suggested row points at your weakest unlocked chapter.
| Chapter | Questions | Tier |
|---|---|---|
| Names and structures | Name the structure, Find the structure, Codes and names, One-letter code | Free |
| Side-chain classes | Side-chain class | Free |
| Genetic code | Codon to amino acid | Free |
| Charge and pH | Net charge at a pH, Predominant form, Isoelectric point, Read the titration curve | Pro |
| Stereochemistry | R or S (2D), R or S (3D), D or L, Rank the groups | Pro |
| Side-chain chemistry | Tap the side-chain group, Name the side-chain group, Side-chain properties | Pro |
| Peptides | Read the sequence, Tap the peptide bonds, Peptide charge, Hydrolysis products | Pro |
Your weakest amino acids come first
Stats lays out all 20 as a grid, shaded by how well you know each one. Tap one to practise it, or press Practise weakest. Questions you missed come back in Review.
The grid, Stats and the review queue come with Pro.
Pro is $4.99, once.
| Feature | Free | Pro, $4.99 once |
|---|---|---|
| All 20 amino acids in 2D and 3D | Yes | Yes |
| Peptide bond and acid-base animations | Yes | Yes |
| Names, side-chain classes, genetic code | Yes, unlimited | Yes |
| Charge and pH, stereochemistry, side-chain chemistry, peptides | No | Yes |
| MCAT mode | No | Yes |
| Review queue and stats | No | Yes |
| Ads | None | None |
One purchase, no subscription. Restore it any time from Settings.
iPhone, iPad and Mac
The same screen on each, drawn here at one sixth of its real pixel size, so the sizes compare honestly.
Notebook notes
Privacy
No account, no ads, no tracking, no analytics. The app makes no network requests, and your progress stays on your device. On the App Store its label will read Data Not Collected. Report this question opens your own mail app, and nothing is sent unless you send it.
Sources
pKa and pI values and side-chain classes follow Lehninger, Principles of Biochemistry, 8th edition (Table 3-1 and Figure 3-5). The genetic code is NCBI table 1. Structure data comes from PubChem. The 2D and 3D drawings are made on the device by MoleculeKit, which is built on RDKit.
Who made it
Alpha Carbon is made by Silkway Studio. Its molecules are drawn by MoleculeKit, the studio's own kit, still in development.
I wanted to change the pH and see which proton leaves first, which no textbook table can show. In all 20 it's the α-carboxyl.
Version 1.0 · Coming to the App Store