What is metabolism?

Metabolism is the term for a set of chemical reactions that occur in the cells of living organisms to sustain life. The metabolic processes lead to growth and reproduction and allow living organisms to maintain their structures and respond to the surrounding environment. All chemical reactions that occur in living organisms, from digestion to the transport of substances from cell to cell, can be part of metabolism.

Intermediary or intermediate metabolism is the term for the transport of substances into and between different cells.

How it works

There are two categories of metabolism: catabolism and anabolism. Catabolism is the breakdown of organic matter, and anabolism uses energy to construct components of cells, such as proteins and nucleic acids.

The chemical reactions in the metabolic process are organized into metabolic pathways whereby one chemical is transformed through a series of steps into another chemical. Enzymes assist in this process by facilitating reactions and serving as catalysts for the reactions to occur. The reactions would not occur without enzymes, which respond to signals between cells and regulate the metabolic pathways. The speed of metabolism is called the metabolic rate.

The metabolism of a living organism allows it to determine which substances are nutritious and useful, and which are poisonous.

Some of the other chemicals and parts of an organism involved in the metabolic process are amino acids, proteins, lipids, carbohydrates, nucleotides, coenzymes and minerals and cofactors.

Metabolic syndrome

Metabolic syndrome describes a group of traits and habits that raise the risk for coronary heart disease, diabetes and stroke. Risk factors include excess fat in the stomach, a high triglyceride level, a low HDL cholesterol level — also known as “good cholesterol” — high blood pressure and high fasting blood sugar.

These factors commonly occur together. However, patients must have at least three of them to be diagnosed with metabolic syndrome.

A person with metabolic syndrome doubles their risk for developing heart disease, and is five times as likely to be diagnosed with diabetes as someone without metabolic syndrome. It is becoming increasingly common as a result of the rise in obesity rates among adults. It is possible to prevent or delay metabolic syndrome through a healthy diet and exercise.

Additional information may be found at these websites:

http://bloodjournal.hematologylibrary.org/cgi/collection/gene_expression

http://www.nlm.nih.gov/medlineplus/ency/article/003706.htm

http://www.mayoclinic.com/health/metabolism/WT00006/

http://www.nature.com/jcbfm/index.html

http://www.nutritionandmetabolism.com/

http://www.hormone.org/Public/endocrinologist.cfm

http://www.nlm.nih.gov/medlineplus/ency/article/002257.htm

http://www.ncbi.nlm.nih.gov/books/NBK22/?depth=10

http://endo.endojournals.org/

http://www.mayoclinic.org/medicalprofs/glucocorticoid-induced-diabetes.html

http://www.nlm.nih.gov/medlineplus/steroids.html