Proteins are natural organic compounds, which have a high molecular weight structure.Molecule of these substances is nerazvetvlyayuschimsya polymer.Proteins are constructed from 20 amino acids.They represent the minimum structural unit of the molecule - monomer.All components are interconnected protein polypeptide, in other - urea, a link in the chain long enough.This molecular weight can range from a few thousand up to millions of atomic particles.
What may be a protein
to determine the main function of the protein, it is necessary to understand the structure of these substances.At the moment there are two varieties of this important human component: fibrous and globular.Distinguish them mainly due to the difference in the structure of the protein molecule.
perfectly globular substance is dissolved not only in water, but in the salt solutions.When such a protein molecule that has a spherical shape.This good solubility can be readily explained arrangement of charged amino acid residues, which are surrounded by a shell of hydration on the surface of the globule.This is what provides such good contacts with various solvents.It should be noted that the group includes all components of globular enzymes, as well as virtually all biologically active proteins.
Regarding fibrous substances, their molecules have a fibrous structure.The catalytic function of proteins is very important.Therefore, it is hard to perform without adjuvants.Fibrillar proteins do not dissolve either in saline or in ordinary water.These molecules are arranged in parallel polypeptide chains.These substances are involved in the formation of some of the structural elements of connective tissues.It elastin, keratin, collagen.
special group of complex proteins, which consist not only of the amino acids and nucleic acids, carbohydrates and other substances.All of these components play a special role.Of particular importance is the catalytic function of proteins.In addition, such substances are plan respiratory pigments, hormones, as well as protection for any organism.Protein biosynthesis is carried out on ribosomes.This process is determined by the broadcast source of nucleic acids.
catalytic function of proteins
catalysis of various chemical substances - is the most important function of proteins.These processes are carried out by enzymes.Are proteins that have specific catalytic properties.Each of these substances may carry one or several similar reactions.Enzymes catalyze the process of splitting of complex molecules and their synthesis.In another of these reactions is called catabolism and anabolism.The catalytic function of proteins and also involves repair of DNA replication and RNA synthesis matrix.
What catalysis
Already in 2013, scientists have identified a little over 5000 enzymes.These substances are able to influence the course of virtually all biochemical reactions.To become more clear catalytic function of proteins is necessary to understand what is catalysis.With Greek this term is translated as "cessation."Catalysis is a change in flow velocity of any chemical reaction.This occurs under the influence of certain compounds.The enzymes act as a catalyst proteins.Examples of this phenomenon is found in everyday life time.Just a man does not notice.
example catalytic function
To understand how the enzyme, it is worth considering a few examples.So, what is the catalytic function of proteins.Examples:
- During photosynthesis ribulezobifosfatkarboksilaza carries catalysis of CO2 fixation.
- Hydrogen peroxide is split into oxygen and water.
- DNA polymerase synthesizes DNA.
- amylase ability to break down starch to maltose.
- degradation of carbonic acid: CO2 + H2O + H + HCO 3.
catalytic function of proteins is to accelerate any chemical reactions.For such reactions include the synthesis, disintegration agents, the individual atoms or transfer electrons from one component to another.
Transport function
Vital activity of any cells should be maintained by various substances, which are for them not just a building material, but also a kind of energy.The biological function of proteins and include transport.These components deliver the cells all important matter, because the membrane constructed of several layers of lipids.It is here are different proteins.At the same time the hydrophilic regions all focused on the surface and tails - in the thickness of the membrane.Such a structure does not allow to penetrate into the cells is very important stuff - alkali metal ions, amino acids and sugars.Proteins carry all of these components into cells for their food.For example, hemoglobin transports oxygen.
Receptor
main function of the protein not only provide the power cells of living organisms, but also help to identify the signals that come from the external environment and neighboring cells.The most striking example of this phenomenon - acetylcholine receptors located on the membrane around interneuronal contacts.The process itself is very important.Proteins perform receptor function and their interaction with acetylcholine is shown in a specific way.As a result, the signal is transmitted into the cell.However, after some time, the neurotransmitter is required to be removed.Only in this case the cell can receive the new signal.It is this function is performed by one of the enzymes - atsetilholtnesteraza that performs the splitting up of choline and acetate gidrolizatsetilholina.
Protective
immune system of any living creature capable of responding to the emergence of foreign particles in the body.In this case, the protective function of the protein.The body is to develop a large number of lymphocytes, which are able to cause damage to pathogenic bacteria, macromolecules, and other cancer cells.One group of these substances carries out the production of specific proteins - immunoglobulin.It is an allocation of these substances in the bloodstream.Immunoglobulins recognize foreign particles and form a highly specific set of a certain stage of destruction.Since the protective function of the protein is carried out.
Structural
function of proteins in the cell goes unnoticed for a man.Certain substances have largely structural significance.These proteins provide mechanical strength to separate tissues in the body.First of all, it is collagen.It is the main component of the extracellular matrix of connective tissues in vivo.
worth noting that mammalian collagen is about 25% of the total weight of proteins.Synthesis of this component occurs in fibroblasts.These are the basic cells of any connective tissue.Originally formed procollagen.This material is a precursor and is chemically treated, which is oxidized to hydroxyproline, proline and lysine residues to gidrksilina.Collagen is produced in the form of three peptide chains, twisted into a spiral.
It's not all the functions of proteins.Biology - quite a complex science, which allows you to identify and recognize the variety of phenomena occurring in the human body.Each function of the protein plays a special role.Thus, in the elastic tissues, such as lung, blood vessel walls and skin there Elastin.This protein is able to stretch and then return to its original shape.
motor protein
muscular contractions - is the process by which the transformation of the energy stored in ATP molecules as a pyrophosphate-energy bonds, is in mechanical work.In this case, the function of the protein in a cell operate myosin and actin.Each of them has its own characteristics.
Myosin has an unusual structure.This protein consists of filamentary sufficiently long portion - tail and several globular heads.Myosin is released, usually in the form of a hexamer.This component is formed by several completely identical polypeptide chains, each of which has a molecular weight of 200 thousand and 4 chains having a molecular weight of only 20,000.
Actin is a globular protein which has the ability to polymerize.This material forms a sufficient length of the structure, which is called F-actin.Only in such a state component can normally interact with myosin.
Examples of the main functions of proteins
Every second in the cells of a living organism occur various processes that would have been impossible without the protein.An example of receptor function such substances can serve as a message cells adrenoceptor accession adrenaline.When exposed to light decomposition of rhodopsin.This phenomenon triggers a reaction and stick-ons.
With regard to the structural features, the best example in this case can serve as an action of collagen.This material gives the connective tissues more elastic.
example transport function of hemoglobin is to carry oxygen around the living body.
In conclusion
It's basic biological functions of proteins.Each of them is very important for the living organism.This particular function is performed corresponding protein.The lack of such components can cause a malfunction of certain organs and systems in the body.
