Protein Structure And Function Of A Protein

Different types of bonds/interactions in proteins lead to different kinds of structures. Three of the most commonly known chemical bonds in proteins include the hydrogen bond, the covalent bond, and the ionic bond. In hydrogen bonds, hydrogen interacts with oxygen, nitrogen, or fluorine to form either the alpha helix, or the beta sheet, which in turn determines its secondary, tertiary, or quaternary structure. Another type of bonds, the covalent bond, links amino acids together by sharing electrons;

Box on right illustrates the peptide bond resulting from the condensation of both the amino acids. The box on the left illustrates the separation of the hydroxide group from glycine and the hydrogen atom from valine.

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.

Proteins are complex structures made up of chains of amino acids. Each protein has a different function such as enzymes to catalyze reactions or protein hormones to trigger certain functions of a cell. First let’s start with the most basic component of a protein: an amino acid. An amino acid is made up of a central carbon atom attached to a hydrogen atom, a carboxyl group, an amino group, and an R group which varies

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.

They are made up of amino acids (consists of amino group, carboxyl group, hydrogen atom, and R group). Polypeptide bonds form between amino acids to form polypeptide chains. Amino acid sequence is primary protein structure. The secondary structure is the bonding pattern of the amino acids (e.g. helix, sheet, etc.). The tertiary structure consists of the domain, where the sheets or helixes fold on each other and become stable. The quaternary structure consists of several polypeptide chains that form advanced proteins such as human leukocyte

The basic building blocks of proteins are amino acids, the biuret reaction tests for protein. A solution of sodium hydroxide is added to a sample then a few drops of copper sulphate solution, if positive – the solution will turn mauve. There are 20 different amino acids and they can be joined in any order. Therefore there can be many different functions. A protein consists of one or more polypeptide chains (a polypeptide chain being multiple amino acids joined together via condensation, producing a peptide bond). Different proteins have different shapes as the shapes are determined by the sequence of amino acids.

The amino acid sequences derived from decoding the mRNA determines a protein's final conformation, helper proteins aid the newly formed polypeptide with its folding to achieve a proper functional shape. These molecular chaperones are essential as the cytoplasm is often filled with new polypeptide chains and thus these accumulation of polypeptide chain might accumulate together and fold into a non-function shape. Example of well studied chaperones from E.Coli are DnaK, DnaJ, GroEL and GroES. And GrpE.

Proteins are made of amino acids, which are compounds built around a central carbon atom. Amino acids then join together through dehydration reactions. These are called peptide bonds. Many amino acids joined together are called polypeptides. A polypeptide becomes a protein when it folds into a three dimensional structure. This is the primary structure of a protein. The next structure in the hierarchy is the secondary structure. Secondary structures can either form alpha helixes, where an amino acid sequence forces the polypeptide to twist into a helical shape; or beta sheets, where an amino acid sequence forces the polypeptide into a zigzag shape. In the tertiary structure, the polypeptide folds several times on itself to form a more complex three dimensional shape. A quaternary structure is when two tertiary structures interact with each other. This is when a protein becomes a functional

B. Original diagram of the different levels of protein structure (i.e., primary, secondary, tertiary, and quaternary).

These proteins differ depending on their function in the cell, but often prevent misfolding of nascent protein, and assist in refolding of the misfolded proteins. Protein folding is dependent on the amino acid sequence within the polypeptide chain that is synthesized from the DNA strand in the ribosome.2 Upon release from the ribosome, the polypeptide chain undergoes a series of conformational changes based on the amino acid sequence to produce a functional protein structure. The assembled native protein is directed to the ER via vesicle

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 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

Campbell and Farrell define proteins as polymers of amino acids that have been covalently joined through peptide bonds to form amino acid chains (61). A short amino acid chain comprising of thirty amino acids forms a peptide, and a longer chain of amino acids forms a polypeptide or a protein. Each of the amino acids making up a protein, has a fundamental design that comprises of a central carbon or alpha carbon that is bonded to a hydrogen element, an amino grouping, a carboxyl grouping, and a unique side chain or the R-group (Campbell and Farrell 61).