Difference Between Kinase and Phosphorylase


Main Difference

The main difference between the Kinase and Phosphorylase is that Kinase catalyzes the addition of phosphate from the ATP to acceptor, whereas Phosphorylase from inorganic phosphate (Pi).

Kinase vs. Phosphorylase

The kinase was first observed in the liver as protein kinase by the Gene Kennedy in 1954, whereas phosphorylase was observed by the Earl W. Sutherland Jr. in the late 1930s as glycogen phosphorylase.

When the donating agency is the high energy ATP molecule, the enzyme involved is a kinase, and when the donating agency is the inorganic phosphate as PO43- from H3PO4 (phosphoric acid) as a phosphorylation source then enzyme involved is phosphorylase. The kinase acceptors are organic molecules like carbohydrates, lipids, and proteins, etc. while the phosphorylase acceptors are specific substances or monomeric subunits like glycogen, starch, etc.


Kinases are not involved in the bond-breaking of a substrate during the transfer of the phosphate group, while the phosphorylase breaks the bonds of the substrate and specific substance by adding the phosphate group. The typical kind of kinase is protein kinase among the carbohydrates and lipids kinases, while the common type of phosphorylase is the glycogen phosphorylase.

Comparison Chart

Phosphorylation takes place by the addition of phosphate from the high energy ATP, is known as a kinase.Phosphorylation occurs from the transfer of phosphate from the inorganic phosphate, is known as phosphorylase.
In 1954sIn the late 1930s
Phosphate Source
ATP (organic chemical)Inorganic phosphate(Pi)
Bond Breaking
Don’t break bonds of the substrateBreak the bonds of the substrate
Organic molecules (glucose, proteins, lipids, etc.)Monomeric molecules as glucose, lactose
PH Range
About 7.4, also at 5.0From 6-7
Protein kinases, lipids kinases, carbs kinases, etc.Glycogen phosphorylases etc.

What is Kinase?

Kinase in the form of the biological catalyst is one of the kinds of phosphotransferase which catalyze the phosphorylation by the transfer of phosphate group from the inorganic phosphate (PO43-). The kinase acts in various enzymatic reactions, not involved in the bond-breaking of the substrate.

Kinases play the role as a phosphotransferase, which regulates the functions of cells by transfer of phosphate from the donor ATP to substrate molecules such as glucose, proteins, and lipids as well. Kinase doesn’t break the bonds of substrate molecules on which they act during the transfer of phosphate groups. Some of the substrates are riboflavin, creatine, etc. Kinase acts as transmitting signals source regulating the complex processes in cells.


Classification of Kinase

  • Protein Kinase: One of the diverse and most significant functional family of kinases is a protein kinase. They deal with the functions and activity of many proteins by adding the phosphates to amino acids such as tyrosine, threonine, serine, and also histidine. P13K combines phosphorus with oxygen.
  • Lipid Kinase: These acts the reactivity of substrate lipids by the addition of phosphate as phosphoinositide three kinases involved in causing cancer when this lipid kinase act over the catalytic subunit PIK3CA (provides instructions for making p110 alpha protein).
  • Carbohydrate Kinase: These kinases act over the substrate carbohydrates such as glucose and hexokinase (an enzyme used during the glycolysis) regulating various metabolic pathways.

What is Phosphorylase?

Phosphorylase is also one of the kinds of phosphotransferase catalyzing phosphorylation from inorganic phosphates (Pi) to acceptor molecules. Phosphorylase enzymes are involved in the breaking of bonds of substrate and monomer molecule, unlike kinase by phosphate (PO43- ). It is regulated by the phosphorylation and also the allosteric regulation (binding of the enzyme other than the enzyme’s active site on effector molecule).

Phosphorylase is the active form in the activation sense of enzymes than the phosphorylase b. In the process of phosphorylation, ATP is required by the process, whereas in dephosphorylation, free inorganic phosphates are released as Pi. Phosphorylases are different from the phosphatases which remove the phosphate group from the donor by water. Phosphorylases also include the allosteric enzymes (can change their shape on binding of the effector, which play the role of catalyst for the production of glucose-1-phosphate from the glucan such as glycogen, starch, etc.

They are named accordingly by the addition of a substrate name with the phosphorylase as glycogen/starch phosphorylase is named as when substrate starch is acted by phosphorylase during the addition of phosphate from an inorganic phosphate.

Examples of phosphorylase are trehalose phosphorylase, glycogen/starch phosphorylase ( In glycogenesis), polynucleotide phosphorylase. The enzymatic disorders caused by phosphorylase are Glycogen storage disease type V-muscle glycogen and Glycogen storage disease type VI-liver glycogen.

Classification of Phosphorylase

  • Glycosyl Phosphotransferase: Enzymes removing glucose from glucans, e.g., maltodextrin phosphorylase, starch phosphorylase. Enzymes are breaking nucleosides into subunits of bases and sugars, e.g., purine nucleosides phosphorylase.
  • Nucleotidyl Phosphotransferase: Having activity of exonuclease 3’ to 5’ position, e.g., polynucleotide phosphorylated.

Key Differences

  1. Kinases add the phosphate from ATP to the substrate, while phosphorylase adds phosphate from the inorganic phosphate to the substrate.
  2. Kinases do not involve the bond-breaking, whereas phosphorylase involved the bond breaking in the substrate molecules.
  3. Kinase adds the phosphate to the organic molecules such as carbohydrates, proteins, and lipids; phosphorylase adds phosphate to monomers like glycogen, starch, etc.
  4. Kinases are only regulated by phosphorylation; on the other hand, phosphorylases are regulated by both allosteric as well as phosphorylation.
  5. Kinase involves in the proteins, lipids kinases, whereas phosphorylase involves glycogen, starch phosphorylase.
  6. Kinase uses ATP; phosphorylase uses inorganic phosphate as a source of phosphate on a substrate.
  7. Kinases include the lipid kinases, protein kinases, and carbohydrates kinases; conversely, phosphorylases include the starch phosphorylase, glycogen phosphorylase, and polynucleotide phosphorylase.


Kinase is a kind of phosphotransferase that dominates phosphate from ATP, whereas phosphorylase donates phosphate from inorganic phosphate to substrate molecule.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White

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