By Neil Osterweil From the WebMD Archives High-protein, low-carbohydrate diets are the hottest thing since sliced flank steak, and every food marketer in the known universe appears to want a piece of the protein pie. Body builders are snatching, grabbing, and gulping down protein shakes. Dieters are gobbling down protein bars and shunning pasta in hopes of quick weight loss. Protein is an important component of every cell in the body.
Many biologists regard proteins as being the fundamental compounds of living systems. Whether or not any one type of molecule may be singled out as "fundamental" is open to question, but proteins play many extremely important roles. Although they are structurally and functionally diverse, they exhibit certain characteristics which enable us to make some generalizations about them.
In terms of elementary chemical composition, proteins always contain carbon, hydrogen, oxygen, and nitrogen, and they usually contain sulfur as well.
The micro molecular units are called amino acids, and a given protein molecule may consist of several hundred or even thousands of these units. The feature shared by all amino acids is a carbon atom to which is attached a carboxyl group and an amino group. These compounds are called amino acids because of the amino and carboxyl groups.
A complete listing and illustration of their structure may be found in most textbooks concerned with organic chemistry.
When amino acids link together, they do so in such a way that the acid group of one is attached to the amino group of another. The bond thus formed between the carbon of the acid group and the nitrogen group if termed a Peptide Bond. This can be illustrated by showing how to amino acids are joined together.
In this particular example, the two simplest amino acids, glycogen and almandine, are subjected to dehydration. As shown, the carboxyl group of one molecule gives up its OH and the amino group of the other reacting molecule gives up one H. Water is thus formed, and the two molecules are linked from carbon to nitrogen.
By addition of any one of the twenty amino acids to this deceptive, a tripe tide would be formed. In similar fashion, continued addition to the chain would lead to the formation of a large polypeptide chain, or large protein molecule.
The specific amino acid sequence of any given protein molecule is called its primary structure. When we consider that there are twenty different amino acids which may be arranged in any order to form a sequence of hundreds of amino acids in the formation of a single protein molecule, it becomes apparent that a vast number of different protein molecules can exist.
This situation is analogous to having an alphabet of twenty letters with which to form words. If there is no prescribed sequence in which the letters must appear, then the number of words that can be formed becomes almost infinities.
As we shall see, this high degree of structural diversity if very important in the many and varied functional roles fulfilled by proteins in living systems.
For the most part, they are coiled or twisted in a number of ways, the most common of which is a spiral twisting called an alpha helix. The geometry of an alpha helix can be visualized by letting a pipe cleaner of certain length represent a straight chain of amino acids.
If the pipe cleaner is coiled around a pencil by proceeding from the tip of the pencil to the eraser in clockwise fashion; an alpha helix is formed. It shape can be seen more clearly if the pencil is then slipped out. Experimental evidence indicates that this alpha helix is produced from a straight chain molecule whenever weak hydrogen bonds pull adjacent parts of the molecule into a helical form.
Hydrogen bonding is thought to be an electrostatic attraction between the positively charged hydrogen end of polar molecule and an unshared electron pair of one atom of another molecule.The Benefits of Protein.
Protein is an important component of every cell in the body. The reasons why have to do with how high-protein/low-carb diets are thought to lead to weight loss. Lean proteins, such as chicken without the skin, fish, or turkey are th.
Eating protein is important to rebuild muscle and maintain cellular structure.
Lean proteins, such as chicken without the skin, fish, or turkey are th Why is eating protein important? Advertisement. Advertisement.
Jessica Crandall on behalf of Academy of Nutrition and. Proteins can easily be addressed as one of the most important molecules in animal cells. There are many varieties of protein molecules which allow a vast range of biological activities in the cell. Protein biosynthesis is an extremely important mechanism because the functions served by the proteins are numerous, ranging from catalysis of cellular .
Proteins are large macromolecules which consist of hydrogen, carbon and oxygen; proteins are polymeric chains that are built from monomers known as amino acids.
- G Proteins Proteins play various important roles in inter-neuronal communication. Receptor sites are made up of proteins and the ion channels in the cell membranes are proteins. The link between the receptor sites and the protein channels sometimes is the guanine nucleotide-binding protein, better known as G Protein.