a difference between the two sides of a cellular membrane. The gradient is made up of a difference in the concentration of a molecule (a chemical gradient) and/or a difference in electrical potential (an electrical gradient).
Driving force that causes an ion to move across a membrane due to the combined influence of a difference in its concentration on the two sides of the membrane and the electrical charge difference across the membrane.
The combination of the concen-tration gradient and the electrical gradient (voltage difference) of an ion distributed unequally across a biological membrane.
The diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential.
The sum of the combined forces of concentration gradient and electrical gradient acting on an ion
Determines the relative concentration of charged ions across a membrane. Distribution of ions depends on concentration and electrical gradient across the membrane - electrochemical gradient - and membrane permeability to the ions.
In cellular biology, an electrochemical gradient refers to the electrical and chemical properties across a membrane. These are often due to ion gradients, particularly proton gradients, and can represent a type of potential energy available for work in a cell. This can be calculated as a thermodynamic measure termed electrochemical potential that combines the concepts of energy stored in the form of chemical potential which accounts for an ion's concentration gradient across a cellular membrane and electrostatics which accounts for an ion's tendency to move relative to the membrane potential.
