Adenosine vs Caffeine: what is the difference?
Adenosine is the body's own sleepiness signal and caffeine blocks its receptors without switching them on, so the two are opponents rather than alternatives.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Drawn the same way round on the skeleton they share. Aligned; 15 atoms differ, too many to mark as one group.
Side by side
| Adenosine | Caffeine | |
|---|---|---|
| Molecular weightCalculated PubChem | 267.24 g/molC10H13N5O4 | 194.19 g/molC8H10N4O2 |
| Hydrogen-bond donorsCalculated PubChem | 4 | 0 |
| Half-life in the bodyEditorial MoleculeFinder curated | Not recorded | about 5 h |
| Where each turns upEditorial MoleculeFinder food and product lists | Not on our lists |
|
| FamilyEditorial MoleculeFinder curated | Nucleobases | Plant alkaloids, Stimulants |
| Everyday groupEditorial MoleculeFinder curated | Body | Food & flavor |
| Chemical groupsCalculated Found by rule (RDKit) | Alcohols, Amines, Ethers | Not recorded |
| Hazard labelReported ECHA via PubChem; ECHA, EU CLP Regulation, Safe Work Australia via PubChem | Warning | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| LD50Measured HSDB via PubChem | 500 mg/kgpure adenosine, mouse, another route | 192 mg/kgpure caffeine, rat, oral |
| A single acute animal measure, here in two different species. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Half-life in the bodyfrom sourceMoleculeFinder curatedIn a typical adult: the time the body takes to clear half of it.
- Where each turns upfrom sourceMoleculeFinder food and product listsEach amount is an editorial figure from our lists, not a measurement of any one product. Each mark is set by hand on the list, never inferred.
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Chemical groupscomputedFound by rule (RDKit)Each group is found in the structure by a chemical pattern.
- Hazard labelfrom sourceECHA via PubChem; ECHA, EU CLP Regulation, Safe Work Australia via PubChem
- LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- EU CLP Regulationfrom sourceAttributionSource: EUR-Lex, Regulation (EC) No 1272/2008, © European Union.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Identifiersfrom sourcePubChemPubChem CID 60961 (Adenosine) and 2519 (Caffeine).
In more detail
That opposition is the whole reason the pair is interesting. Adenosine is a molecule your body makes continuously while you are awake, and as it accumulates and settles onto its receptors, you feel more and more like sleeping. Caffeine happens to fit those same receptors closely enough to occupy them without switching them on, so the sleepiness signal keeps being sent and stops being heard. Nothing is added by the coffee: the alertness is the absence of a message. When the caffeine clears, the adenosine that piled up in the meantime is still there and lands all at once, which is what an afternoon crash actually is. Their structures show the family resemblance, both purines, adenosine carrying a whole ribose sugar that caffeine lacks.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Adenosine and Caffeine?
- Adenosine is the body's own sleepiness signal and caffeine blocks its receptors without switching them on, so the two are opponents rather than alternatives.
- Is Adenosine bigger than Caffeine?
- Adenosine is the heavier molecule, 267.24 g/mol against 194.19 g/mol for Caffeine. Adenosine is C10H13N5O4 and Caffeine is C8H10N4O2.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.