Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together between the carboxyl atom of one amino acid and the amine nitrogen of another.

This bond is called a peptide bond.

The sequence of amino acids in a protein is defined by a gene and encoded in the genetic code.

Although this genetic code specifies 20 "standard" amino acids, the residues in a protein are often chemically altered in post-translational modification: either before the protein can function in the cell, or as part of control mechanisms.

Proteins can also work together to achieve a particular function, and they often associate to form stable complexes. Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of all living organisms and participate in every process within cells.

Many proteins are enzymes that catalyze biochemical reactions, and are vital to metabolism.

Other proteins have structural or mechanical functions, such as the proteins in the cytoskeleton, which forms a system of scaffolding that maintains cell shape.

Proteins are also important in cell signaling, immune responses, cell adhesion, and the cell cycle.

Protein is also a necessary component in our diet, since animals cannot synthesise all the amino acids and must obtain essential amino acids from food.

Through the process of digestion, animals break down ingested protein into free amino acids that can be used for protein synthesis..

For more information about the topic Protein, read the full article at Wikipedia.org, or see the following related articles:

Denaturation (biochemistry) — Denaturation is the alteration of a protein shape through some form of external stress (for example, by applying heat, acid or alkali), in such a way ...  > read more

Protein folding — Protein folding is the process by which a protein structure assumes its functional shape or conformation. All protein molecules are heterogeneous ...  > read more

Peptide bond — A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other ...  > read more

Protein biosynthesis — Protein biosynthesis (Synthesis) is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but ...  > read more

Related Stories

Conserved Amino Acids Play Both Structural And Mechanistic Roles In Sandwich-like Protein (March 17, 2005) — The question of whether amino acids in sandwich-like proteins are there to stabilize the structure or to speed up the protein-folding process is best answered by "all of the above," according ...  > read more

'Super Yeasts' Produce 300 Times More Protein Than Previously Possible (May 13, 2008) — Researchers in California report development of a new kind of genetically modified yeast cell that produces complex proteins up to 300 times more than possible in the past. These "super yeasts" could ...  > read more

Nature’s Origami: Protein Folding Is 'Hit And Miss' Process (March 11, 2009) — Sometimes known as "nature's origami", the way that proteins fold is vital to ensuring they function correctly. But researchers at the University of Leeds have discovered this is a 'hit and miss' ...  > read more

'Fishy' Clue Helps Establish How Proteins Evolve (January 29, 2009) — Three billion years ago, a "new" amino acid was added to the alphabet of 20 that commonly make up proteins in organisms today. Now researchers have demonstrated how this rare amino acid -- and, by ...  > read more

Quality Control System Ensures Genetic Instructions Are Ready To Go (December 16, 1998) — Cells pay even closer attention to quality control of genetic information than scientists previously thought, according to new findings by University of Wisconsin Medical School researchers. Before ...  > read more

Search ScienceDaily

Blood Test For Breast Cancer