What are the differences between primary and secondary active transport?

Question

Accepted Answer

Basis of differentiation

Primary active transport

Secondary active transport

Definition

Primary active transport is the transport of molecules against a concentration gradient through the use of energy generated by ATP

Secondary active transport is the transport of two distinct molecules across a membrane using energy in other forms than ATP

Number of molecules transported

A single molecule is transported

Two types of molecules are transported simultaneously

Energy source

Uses energy generated from ATP

The concentration gradient of driving ion supplies energy for the transport of the driving ion/molecule against its concentration gradient

Number of substances transported

May transport one or more substances

Must transport more than one substance

Types of transmembrane proteins used

Transmembrane proteins are specific to the ion transported through them

Both antiporters and symporters are used in secondary active transport

Types of molecules transported

Ions like sodium, potassium, and calcium are transported across cell membrane

Ions like sodium act as the driving molecules

Examples

Sodium potassium pump, calcium pump in muscles

Glucose-sodium pump, sodium-potassium pump

Basis of differentiation	Primary active transport	Secondary active transport
Definition	Primary active transport is the transport of molecules against a concentration gradient through the use of energy generated by ATP	Secondary active transport is the transport of two distinct molecules across a membrane using energy in other forms than ATP
Number of molecules transported	A single molecule is transported	Two types of molecules are transported simultaneously
Energy source	Uses energy generated from ATP	The concentration gradient of driving ion supplies energy for the transport of the driving ion/molecule against its concentration gradient
Number of substances transported	May transport one or more substances	Must transport more than one substance
Types of transmembrane proteins used	Transmembrane proteins are specific to the ion transported through them	Both antiporters and symporters are used in secondary active transport
Types of molecules transported	Ions like sodium, potassium, and calcium are transported across cell membrane	Ions like sodium act as the driving molecules
Examples	Sodium potassium pump, calcium pump in muscles	Glucose-sodium pump, sodium-potassium pump