Upstream and downstream (transduction)
Encyclopedia
In molecular biology, the terms upstream and downstream can refer to the temporal and mechanistic order of cellular and molecular events. For example, in signal transduction
, the second messenger acts downstream to activation of cell membrane
receptor
s. The other way around, activation of cell membrane
receptor
s occurs upstream of the production of second messengers.
Signal transduction
Signal transduction occurs when an extracellular signaling molecule activates a cell surface receptor. In turn, this receptor alters intracellular molecules creating a response...
, the second messenger acts downstream to activation of cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
receptor
Receptor (biochemistry)
In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...
s. The other way around, activation of cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
receptor
Receptor (biochemistry)
In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...
s occurs upstream of the production of second messengers.