Difference Between Cyclic AMP and AMP

Key Difference – Cyclic AMP vs AMP
 

Adenosine monophosphate (AMP) is a nucleotide that contains a phosphate group, a ribose sugar, and a nucleobase adenine. Cyclic AMP is considered as a secondary messenger that mainly involves during intra-cellular signal transduction processes. The key difference between a cyclic AMP and AMP is with regards to the structure of both compounds; cyclic AMP is present in a cyclic structure while AMP is present in a non-cyclic structure.

Cellular metabolic processes are driven by different components present within the cells themselves. They could be sources of energy or regulatory molecules. All cellular metabolic pathways are regulated at different levels. AMP and cyclic AMP are such compounds that mainly involve cell metabolism.

CONTENTS

1. Overview and Key Difference
2. What is Cyclic AMP
3. What is AMP
4. Similarities Between Cyclic AMP and AMP
5. Side by Side Comparison – Cyclic AMP vs AMP in Tabular Form
6. Summary

What is Cyclic AMP?

Cyclic adenosine monophosphate (cAMP) is a second messenger, a derivative of ATP that is important in many biological processes such as intracellular signal transduction, etc. The most important role of cAMP is the regulation of metabolism. This could be further explained where cAMP performs a major role in the context of facilitation and mobilization promotion of glucose and fatty acid reserves.

In the liver, intracellular cAMP levels are increased due to the stimulation of adenyl cyclase by glucagon and . This condition, where the cAMP levels are high results in a net increment of hepatic glucose production. This increment occurs according to three different pathways; stimulation of phosphorylase activation, suppression of glycogen synthetase activity and stimulation of gluconeogenesis.

The major effects of cAMP in tissues are lipolysis and glycogenolysis in adipose tissue and muscle tissue respectively. cAMP also has the potential to enhance the release of insulin from beta cells of the pancreas. The released insulin is moved up along into liver and adipose tissue where it suppresses the accumulation of high levels of cAMP. cAMP has the ability in mediating actions of several hormones that are catabolic. Since cAMP has the potential to release insulin, its involvement in diabetes is currently being discussed.

What is AMP?

Adenosine monophosphate (AMP) is defined as a nucleotide that contains a phosphate group, a ribose sugar and a nucleobase; adenine. AMP is an ester of phosphoric acid and is also termed as 5-adenylic acid.  The most important role that is performed by AMP during most of the cellular metabolic processes is its ability to be inter-converted into ADP (adenosine diphosphate) and/or ATP (Adenosine triphosphate). AMP is also important during the synthesis of RNA.

With regards to the structure of AMP, it does not contain a high energy phophoanhydride bond in ADP or ATP. AMP could be synthesized using different pathways. It can be synthesized from ADP where two ADP molecules are converted to one ATP molecule and one AMP molecule (2ADP → ATP + AMP). In another pathway, AMP could be synthesized using the hydrolysis of the high energy phosphate bond of ADP (ADP + H₂O → AMP + Pi) or ATP (ATP + H₂O → AMP + PPi).

AMP also has the potential to be converted to ADP or ATP. Initially, AMP is converted to ADP and ADP is converted ATP in the presence of inorganic phosphate. The reaction could be summarized as follows.

AMP + ATP → 2 ADP

ADP + P_i → ATP

AMP can also be converted into IMP (Inosine monophosphate) in the presence of the enzyme myoadenylate deaminase. In this reaction, an ammonia group is released. In the context of a catabolic pathway, AMP could be converted into uric acid that is excreted from mammalian bodies.

What are the Similarities Between Cyclic AMP and AMP?

• Both contain an adenine base, a phosphate group and a ribose sugar.
• Both cAMP and AMP are derivatives of ATP.
• Both cAMP and AMP are nucleotides.

What is the Difference Between Cyclic AMP and AMP?

Summary – Cyclic AMP vs AMP

AMP and cyclic AMP are compounds that mainly involves cell metabolism. Cyclic AMP is considered as a secondary messenger that mainly involves intra-cellular signal transduction processes. cAMP performs a major role in facilitation and mobilization promotion of glucose and fatty acid reserves. cAMP in tissues results in lipolysis and glycogenolysis in adipose tissue and muscle tissue respectively. Since it influences the release of insulin, currently it is under research to investigate its link to diabetes. Adenosine monophosphate (AMP) is defined as a nucleotide that contains a phosphate group, a ribose sugar and a nucleobase adenine. The important role that is performed by AMP during cellular metabolic processes is its ability to be inter-converted into ADP or ATP that carry high energy bonds. This is the difference between cAMP and AMP.

Reference:

1.Sutherland, Earl W, and G Alan Robison. “The Role of Cyclic AMP in the Control of Carbohydrate Metabolism.” Diabetes, American Diabetes Association, 1 Dec. 1969. Available here 
2.“Adenosine Monophosphate.” Encyclopædia Britannica, Encyclopædia Britannica, Inc. Available here  

Image Courtesy:

1.’Cyclic-adenosine-monophosphate-2D-skeletal’By Benjah-bmm27 – Own work, (Public Domain) via Commons Wikimedia
2.’Adenosinmonophosphat protoniert’By NEUROtiker – Own work, (Public Domain) via Commons Wikimedia