digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Glycogenesis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage. This process is activated during rest periods following the Cori cycle, in the liver, and also activated by insulin in response to high glucose levels, for example after a carbohydrate-containing meal.

Steps[edit]

Control and regulations[edit]

Glycogenesis responds to hormonal control.

One of the main forms of control is the varied phosphorylation of glycogen synthase and glycogen phosphorylase. This is regulated by enzymes under the control of hormonal activity, which is in turn regulated by many factors. As such, there are many different possible effectors when compared to allosteric systems of regulation.

Epinephrine (Adrenaline)[edit]

Glycogen phosphorylase is activated by phosphorylation, whereas glycogen synthase is inhibited.

Glycogen phosphorylase is converted from its less active "b" form to an active "a" form by the enzyme phosphorylase kinase. This latter enzyme is itself activated by protein kinase A and deactivated by phosphoprotein phosphatase-1.

Protein kinase A itself is activated by the hormone adrenaline. Epinephrine binds to a receptor protein that activates adenylate cyclase. The latter enzyme causes the formation of cyclic AMP from ATP; two molecules of cyclic AMP bind to the regulatory subunit of protein kinase A, which activates it allowing the catalytic subunit of protein kinase A to dissociate from the assembly and to phosphorylate other proteins.

Returning to glycogen phosphorylase, the less active "b" form can itself be activated without the conformational change. 5'AMP acts as an allosteric activator, whereas ATP is an inhibitor, as already seen with phosphofructokinase control, helping to change the rate of flux in response to energy demand.

Epinephrine not only activates glycogen phosphorylase but also inhibits glycogen synthase. This amplifies the effect of activating glycogen phosphorylase. This inhibition is achieved by a similar mechanism, as protein kinase A acts to phosphorylate the enzyme, which lowers activity. This is known as co-ordinate reciprocal control. Refer to glycolysis for further information of the regulation of glycogenesis.

Insulin[edit]

Insulin has an antagonistic effect to epinephrine signaling via the beta-adrenergic receptor (G-Protein coupled receptor). When insulin binds to its receptor (insulin receptor), it results in the activation (phosphorylation) of Akt which in turn activates Phosphodiesterase (PDE). PDE then will inhibit cyclic AMP (cAMP) action and cause inactivation of PKA which will cause Hormone Sensitive Lipase (HSL) to be dephosphorylated and inactive so that lipolysis and lipogenesis is not occurring simultaneously.

Calcium ions[edit]

Calcium ions or cyclic AMP (cAMP) act as secondary messengers. This is an example of negative control. The calcium ions activate phosphorylase kinase. This activates glycogen phosphorylase and inhibits glycogen synthase.

See also[edit]

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Glycogenesis — Please support Wikipedia.
A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
599 videos foundNext > 

Glycogenesis

www.SalmonellaPlace.com This is a tutorial/lecture on Glycogenesis. We cover some topics important for classes such as Biology, Biochemistry, Physiology, etc...

Glycogenesis

Human Metabolism Map II - Gluconeogenesis & Glycogenesis

http://www.facebook.com/ArmandoHasudungan Song: Angus & Julia Stone - Devil's Tears Image: https://docs.google.com/open?id=0B8Ss3-wJfHrpbTFkM3o0S3lSd1U.

Animation of Glycogenesis

In order to store glycogen, the cell can undergo glycogenesis. This leads to long chains of glycogen molecules. The process of glycogenesis is more thoroughl...

Glycogenesis

Dr. Pepper delivers the basics on the glycogenesis pathway.

glycogenesis glycogenolysis

Glycogen: Glycogenesis

Review Questions What type of enzymes catalyze the formation of complex carbs by catalysing the formation of glycosidic bonds? The sugar that's added to the ...

Glycogenolysis

www.SalmonellaPlace.com This is a tutorial/lecture on Glycogenolysis. We cover some topics important for classes such as Biology, Biochemistry, Physiology, e...

Glycogenesis and Glycogenolysis by Dr AA & Dr XX

glycogenesis

Created using PowToon -- Free sign up at http://www.powtoon.com/ . Make your own animated videos and animated presentations for free. PowToon is a free to...

599 videos foundNext > 

3 news items

 
STACK News
Thu, 10 Apr 2014 09:12:30 -0700

But don't stuff your face with every carb-heavy food in your cabinet. You need to carefully craft your carb consumption. Glycogenesis is the process of storing carbs as energy. This energy source (muscle glycogen) is important to athletic performance ...

BioNews Texas

BioNews Texas
Mon, 07 Apr 2014 05:47:47 -0700

Overactivity of beta cells in the pancreas produce excess insulin (neonatal hyperinsulinism) due to structural, functional, or genetic abnormalities in the glucose-sensing mechanisms in the body. This causes glycogenesis in high rates in hepatic and ...

LiveScience.com

LiveScience.com
Mon, 31 Mar 2014 13:22:44 -0700

As the small intestine absorbs glucose, the pancreas releases insulin, which stimulates body tissues and causes them to absorb this glucose and metabolize it (a process known as glycogenesis). This stored glucose (glycogen) is used to maintain healthy ...
Loading

Oops, we seem to be having trouble contacting Twitter

Talk About Glycogenesis

You can talk about Glycogenesis with people all over the world in our discussions.

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!