Proteins

brought to you by: Jones M. and Justin W.


What is it?

A protein is an organic macromolecule composed of long chains of subunits called amino acids. All living things use the same kinds of amino acids to construct proteins. Proteins differ in the number of amino acids they contain and in the sequence in which the amino acids occur. As a consequence, there is an almost endless variety of possible proteins. For ferent proteins containing 100 amino acids could be made by cell. Since there are 20 amino acids that can potentially occupy each position in the chain, there are many trillions of possible of this length.

How does it work?

Once scientists understood the structure of DNA, they were able to study how a specific protein is built from information found the DNA of one gene. Scientists now know that DNA is used as a blueprint to make a similar molecule called ribonucleic acid, or RNA for short. This RNA molecule then directs the information of proteins. Gene expression is the use of the genetic information in the DNA to make proteins. Gene expression takes place in 2 stages. The first stage is called transcription. During this, an RNA copy of a gene is made. During translation, the second stage of gene expression, 3 kinds of RNA work together to assemble amino acids into a protein molecule.

What does it do?

Proteins often play structural roles in organisms. Cartilage and tendons are made of a protein called collagen, which also gives strength to your skin and bones. A protein called keratin forms the horns of a rhinoceros and features of birds as well as your own hair. Proteins play a second important role in organism-they act as enzymes. It increases the rate at which chemical reaction occur, such as those that take place during metabolism, the process in which energy get burned for doing work. Most of the chemical reactions necessary for growth, movement, and other activities could not take place without enzymes.


Links

Proteins

Proteins

Proteins

Proteins

Proteins

 

Return to the Beginning