Connectivity map
Each node is a pathway. An edge means a molecule produced by one is consumed by the other. Common carriers are excluded, otherwise everything joins to everything.
Network
Circles — how connected a pathway is
- Hub Connects to a large share of the map. Disturb one of these and the effect travels widely.
- Connector Several links in and out. Typical of a pathway that both consumes and supplies intermediates.
- Peripheral A handful of links, usually to close relatives within the same category.
- Terminal One or two links. Either a short pathway or one the source documents describe in isolation.
Lines — what the connections mean
- Violet joins two different categories — for example carbohydrate metabolism feeding lipid metabolism. These are the interesting ones.
- Grey joins two pathways inside the same category.
- Thickness is the number of different molecules shared. A thick line means the two pathways trade several intermediates, not just one.
› How to read this map
Think of each circle as a factory and each line as a delivery route. A line is drawn from one pathway to another when the first one makes a molecule that the second one uses. So the map is not about which pathways look similar; it is about which ones hand material to each other.
Big violet circles are the busy junctions. They sit in the middle of many deliveries, which is usually why a defect in one of them shows up in several organ systems at once. Small grey circles at the edge either are short pathways or are described on their own in the source documents, so they have few recorded hand-offs.
Common carriers such as ATP, NAD+ and water are deliberately left out. They take part in almost every reaction, so including them would connect everything to everything and the picture would say nothing. What remains are the specific intermediates.
Two cautions. A line means a connection exists somewhere in this dataset, not that material actually flows that way in a given tissue at a given moment — check the compartment and tissue on each pathway page. And a missing line may only mean the source documents did not record that step, not that biology lacks it.
Hover any circle for its name and connection count, hover any line for the molecules it carries, and click either to open the pathway behind it.
Junction detail
Directed: produced in the first pathway, consumed in the second
Hydroxyethyl-TPP, Thiamine pyrophosphate (TPP)
Hydroxyethyl-TPP, Thiamine pyrophosphate (TPP)
Pyruvate
Pyruvate
Pyruvate
Pyruvate
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Acetyl-CoA
Pyruvate
Pyruvate
Showing all 18 junctions.