It is difficult to describe in a simple sentence the role of proteins.
When there is something to do, it is a protein that does it.
Some examples of proteins
* Antibodies: they recognize molecules of invading organisms.
* Receptors: part of the cell membrane, they recognize other
proteins, or chemicals, and inform the cell.
* Enzymes: assemble or digest.
The role (or function) of a protein depends on its shape, and chemical
Proteins play a number of vital roles in all organisms. Unlike
carbohydrates and lipids they always contain nitrogen as well as
carbon, hydrogen and oxygen. Sulphuris often present.
The building blocks of the proteins are amino acids. Proteins are made
of a long chain of amino acids, sometimes modified by the addition of
sugars and phosphates. Amino acids unite to form proteins in much the
same manner the monosaccharides combine to form polysaccharides, and
fatty acids and glycerol combine to form fats and oils. This happens
when two amino acids reacts. The reaction occurs between the amino
group of one amino acid and the carboxyl group of another. To make
this happen a condensation reaction has to occur which involves the
removal of a molecule of water. Once this happens two amino acids
become joined by a peptide link to form a dipeptide. To form a
polypeptide a series of condensation reactions must happen which forms
a longer chain. The individuality of a particular protein is
determined by the sequence of amino acids comprising its polypeptide
chains, together with the pattern of folding and cross-linkages.
... middle of paper ...
...rs, nails, hooves and horns. Collagen
is another fibrous protein. It is the most abundant protein in
vertebrates, making up a third of their total protein mass. The human
body is mainly held together by collagen as it is found in bones,
cartilage, tendons, ligaments, connective tissue and skin. Collagen
fibres have a tensile strength greater than steel which makes it very
strong. Careful analysis of collagen had shown that they consist of
three polypeptide chains coiled round each other in a triple helix.
The resulting structure is like a plaited rope and has great strength.
In conclusion proteins are probably the most important class of
biochemical molecules, although of course lipids and carbohydrates are
also essential for life. Proteins are the basis for the major
structural components of animal and human tissue.
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- Proteins are considered to be the most versatile macromolecules in a living system. This is because they serve crucial functions in all biological processes. Proteins are linear polymers, and they are made up of monomer units that are called amino acids. The sequence of the amino acids linked together is referred to as the primary structure. A protein will spontaneously fold up into a 3D shape caused by the hydrogen bonding of amino acids near each other. This 3D structure is determined by the sequence of the amino acids.... [tags: Amino acid, Protein, Secondary structure]
1463 words (4.2 pages)
- Give an account of the structure and function of neurones’. Author- Casey Shaw 16003465 Neurones are highly specialised cells that are responsible for propagating electrical signals around the body. They are primarily responsible for receiving information about external or internal stimuli and communicating this information to the central nervous system to elicit an appropriate response in target organs. They have specific structures that are designed to help carry out this task. However, there are variations within these structures that are specific to certain neurones that give them their own specialised function.... [tags: Neuron, Action potential, Nervous system, Axon]
1931 words (5.5 pages)
- Hierarchical Structure of Proteins Molecular Cell Biology. 4th edition, Dec 18th, U.S. National Library of Medicine, This article intends to educate the reader on how exactly proteins function and their structure and how the various components of proteins work together to create one cohesive unit. This passage focuses on the spatial arrangement of proteins emphasizing its importance as key to understanding how exactly proteins work. In summary, this excerpt went over how proteins are a linear polymer of amino acids linked together by peptide bonds.... [tags: function, structure, cohesive, protein]
626 words (1.8 pages)
- Long essay 1 The structure of proteins, emphasising the forces that sustain their three dimensional structures. Protein is one of the basic complimentary of living organisms. Its function is highly associated with its chemical properties, which is the protein structure. Protein structures can be divided into 4 levels: primary, secondary, tertiary and quaternary. The basic unit of proteins is the 20 amino acids, which can be divided into 3 groups by the different characteristic of the side chain.... [tags: Amino acid, Protein, Protein structure]
1858 words (5.3 pages)
- Using appropriate examples and diagrams, describe the primary, secondary, tertiary and quaternary structure of proteins. What molecular forces hold these structures. Proteins are a fundamental macromolecule, playing an essential role in the creation of life, coded for by genes in DNA. Proteins have a wide range of functions in the body, with perhaps the most significant being their role as enzymes. It is these enzymes that are responsible for the biological catalysis of almost all essential cellular reactions that constitute basic life.... [tags: Protein, Amino acid, Protein structure]
2089 words (6 pages)
- ... This approach is known as rigid-body docking . It depends from case to case, whether this approximation is accurate enough or not. If there are significant conformational changes within the molecules during the complex formation, this approach is inadequate. However, generation and scoring of all possible conformations is prohibitively expensive in computer time. Flexible docking algorithms  must therefore take into consideration only a selected subset of possible conformational changes.... [tags: structure, ligand, algorithms]
935 words (2.7 pages)
- Proteins are fundamental components of all living cells that participate in some of the most important biological processes, including cell growth and maintenance, movement and defense. They are complex molecules that consist of one or more chains of amino-acids, have distinct three-dimensional shapes and whose structure and structural dynamics directly influence their specific function. Most proteins have a primary, secondary and tertiary structure, but some of them, like hemoglobin, also have a quaternary structure.... [tags: Proteins, Structures, Functions]
1004 words (2.9 pages)
- The Structure of Proteins Introduction 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).... [tags: Chemistry]
1526 words (4.4 pages)
- The primary structure of a protein consists of an amino acid sequence joined covalently in a peptide bond. Amino acids consist of an α amino group (H2N- ), connected to a chiral (with exception to glycine) α carbon bonded to a hydrogen and the unique R-group (-CHR- ), and a carboxyl group (-COOH). A peptide bond is formed through a condensation reaction between the α amino group and the carboxyl group carbon as follows: - NH – CHR – CO – NH – CHR – CO –. Peptide bonds are planar and always in the ‘trans’ formation to prevent steric clash between the amino and carboxyl terminal hydrogen atoms of separate residues in a polypeptide chain. Amino acids within a peptide possess two resonance... [tags: Amino acid, Protein, Protein structure]
1445 words (4.1 pages)
- The Three-Dimensional Structure of Proteins The covalent structure of a protein is composed of hundreds of individual bonds. Because free rotation is possible around a good portion of these bonds, there are a very high number of possible conformations the protein can assume. However, each protein is responsible for a particular chemical or structural function, signifying that each one has a distinctive three-dimensional configuration. By the early 1900’s, numerous proteins had been crystallized.... [tags: atoms, hydrogen bonds]
1261 words (3.6 pages)