Proteins : A Major Molecular Constituent Of Cells

2. protein provide structure in every cell in our body- Proteins are present in all areas and processes of the cell. proteins hep maintain the cell keep its shape, and control the movement of particles in and out of the cell. It also help send signal and repair of damaged cells. Proteins control movement in the cell division.

A protein has multiple existing structures, these are the primary, secondary, tertiary and quaternary structures which occur progressively. A protein is essentially a sequence of amino acids which are bonded adjacently, and interact with one another in various ways depending on the R group that the amino acid contains. There are 20 different amino acids which are able to be arranged in any given order, thus giving rise to a potential 2.433x1018 (4.s.f) different combinations, and therefore interactions between the various amino acids.

The amino acids bond together in bonds called peptide bonds. A chain of amino acids is called a polypeptide chain. The structure in which the amino acids are bonded determines the function of the protein. There are about twenty different amino acids, but there is a wide variety of possible combinations that amino acids can bond, therefore proteins have quite a lot of functions. Some things proteins are used for are the building of the muscles, tendons, organs, glands, nails, and hair. There are many more different functions for proteins. To detect proteins in test materials, there is an identifying agent called Biuret Solution which when mixed with the test material. It turns purple if it contains a protein. The darker the violet color, the more concentrated it is with protein.

The structure of an enzyme as protein has a primary, secondary, tertiary, and sometimes quaternary structure. The primary structure of an enzyme, like any protein, is the order of its amino acids. The secondary structure involves alpha helices and beta pleated sheets. Alpha helices are a coil that is formed by hydrogen bonding between every fourth amino acid. Beta pleated sheets are formed by hydrogen bonding between two or more parts of the polypeptide chain that are side by side. The tertiary structure contains disulfide bridges, ionic bonds, hydrophobic interactions, and hydrogen bonds. Disulfide bridges are the result of two sulfhydryl groups interacting because the the folding of the protein. Ionic bonds can form between polar groups on amino acids. Hydrophobic interactions are the cluster of amino acids with nonpolar side chains that is commonly seen in proteins. Hydrogen bonds can also form. The quaternary structure of an enzyme is when multiple proteins are bonded together in one complex made of proteins subunits.

Proteins are biological macromolecules which consist of a chain of amino acids joined by peptide bonds, which can either be alpha-helix or beta-pleated secondary structures. Amino acids are the monomer of proteins formed of a carboxyl group and an amino group, which are coded for by DNA. Deoxyribose nucleic acid (DNA) is formed by nucleotides which form phosphodiester bonds between them and codes for protein. The DNA is transcribed by mRNA and then translated by tRNA when read in triplet anticodons, which then forms an amino acid, followed by forming proteins. This is simply background information about how proteins are formed, and what allows the monomers of it to exist.

Proteins consist of chains of smaller compounds called amino acids, they contain carbon, hydrogen, oxygen, nitrogen and usually sulfur atoms. Enzymes, antibodies, and the myoglobin are examples of proteins (American Heritage: Student Science Dictionary 272). Protein is a straight chain of amino acids. You need protein to survive (Rader).

Proteins are polymeric chains that are built from monomers called amino acids. All structural and functional properties of proteins derive from the chemical properties of the polypeptide chain. There are four levels of protein structural organization: primary, secondary, tertiary, and quaternary. Primary structure is defined as the linear sequence of amino acids in a polypeptide chain. The secondary structure refers to certain regular geometric figures of the chain. Tertiary structure results from long-range contacts within the chain. The quaternary structure is the organization of protein subunits, or two or more independent polypeptide chains.

Living organisms need proteins in their diet to help the body repair cells and make new ones. The basic structure of protein is a chain of amino acids. When two amino acids join together a dipeptide is formed but when more than two amino acids are joined together a polypeptide is formed. Proteins are made up of one or more polypeptides. Proteins are large molecules made up of the elements hydrogen, oxygen, nitrogen and carbon. Types of proteins include, structural proteins, contractile proteins, hormones, enzymes, antibodies and transport proteins. Some functions of proteins are movement in muscles, tendons and ligaments. Enzymes make biological reactions possible and hormones regulate metabolism. The protein shape determines its function.Proteins

. The 3-D tertiary structure of polypeptide proteins globular and is the result of interactions that occur between R groups. Tertiary structure is a result of the bonds between sidechains of amino acids, the R groups. The structure and bonds involve alpha helices, beta pleated sheets, and also regions unique to each protein. Tertiary proteins are held together by four different types of forces; hydrogen bonds, hydrophobic interactions (including Van der Waals interactions), ionic bonding (electrostatic interactions), and disulfide bridges (strong covalent bonds). Hydrogen bonds occur within and between polypeptide chains and the aqueous environment. Hydrogen bonding forms between a highly electronegative oxygen atom or a nitrogen atom and a hydrogen atom attached to another oxygen atom or a nitrogen atom. This links the amino acid

They are known to be the workhorses of the body cell that carries out diverse catalytic and structural roles into building the structures of all living organisms [15]. The basic structure of protein is a chain of amino acids that supplies energy to a body. There are 20 different naturally occurring amino acids that make all types of protein. Proteins come in various sizes and shapes. Some comes in a thread-like shape known as fibrous proteins and they tend to have structural or mechanical roles. Others come in spherical shapes, known as the globular proteins [16]. These spherical proteins function as enzymes, transport proteins, or antibodies. The key function of protein is based on its ability to recognize and bind specific ally to molecules, it also need to be in the right shape in other to function properly [15]. The primary structure of proteins is a linear sequence of amino acids encoded by DNA. This sequence controls how protein folds into three dimensional structure, the stability of its resulting structure [17], and functions. It is important to add that protein is an important building block of bones, skin, blood and

Amino acids are the smaller building blocks which protein is made of. There are 20 different amino acids. Depending on length, sequence of amino acids and function; each protein has unique different from each other. These amino acids have unique 3D shapes by fold up in complex ways.

We know that proteins are basically just amino acids bonded by peptide bonds which form a chain. However the function of protein is determined by the structure of that protein itself, we can determine the structure of an amino acid by observing what sequence the amino are in, each protein or polypeptide as its own unique sequence of amino acids, we refer

a) The tertiary structure refers to the structural arrangement of amino acids that are found far away from one another along the polypeptide chain. The tertiary structure is overall a three dimensional shape of a protein molecule. It will bend and twist to achieve maximum stability. The shape of a tertiary structure is made when the secondary structure folds in on itself and is held in place by many bonds and interactions formed by the R groups in the amino acid chain. The bonds and interactions involved are hydrogen bonds, ionic bonds, hydrophobic interactions and disulphide bonds. These bonds and interactions are located in different areas of the tertiary structure, the hydrogen bonds are located inbetween polar R groups, ionic bonds are located between charged R groups, hydrophobic interactions are located between nonpolar R groups and disulphide bonds are formed generally in the endoplasmic reticulum by oxidation ."Hydrogen bonds may form between different side­chain groups." Hydrophobic interactions are brought about in an aqueous site. The tertiary structure is held together mainly by interactions that are located at the R groups.

Bettelheim, Brown, Campbell and Farrell assert that polypeptide chains do not extend in straight lines but rather they fold in various ways and give rise to a large number of three-dimensional structures (594). This folding or conformation of amino acids in the localized regions of the polypeptide chains defines the secondary structure of proteins. The main force responsible for the secondary structure is the non-covalent

Proteins play a role in almost every physiological process that takes place in our body and understanding protein functionality can lead to a better understanding human biology and life itself. The central dogma of biology describes the flow of genetic information from DNA to RNA to proteins. It has long been established that the structure of the protein determines the function, however this idea has been challenged in recent years by the discovery of intrinsically disordered proteins. Protein structure determines the key characteristics exhibited by the protein and can determine its role in biological processes. Proteins are comprised of amino acids; this sequence of amino acid residues describes the protein’s primary structure. The