What are proteins? According to the dictionary , which basically sums up the true meaning of what they are, proteins are large biomolecules consisting of one or more long chains of amino acid residues. Which can serve the body in an array of positive ways. Proteins support growth and maintenance of the body and muscle structure. Proteins build new enzymes, hormones, and neurotransmitters. They refresh and replenish the structure and shape of your hair, as well as helping your skin color not dull. Proteins maintain acid-base balance which acts as a buffer, for clotting of blood in your veins and body. They provide your body and immune system with energy and can remove glucose from your liver and kidneys. Proteins prevent edema transportation across your cell membrane. They are also like machines that make all living things, whether viruses, bacteria, butterflies, jellyfish, plants, or humans function. They are a major part of your skin, nails , hair, muscle, bone , and internal organs. According to an article written by Harvard , they were first described by the Dutch chemist , Gerardus Johannes Mulder and named by the Swedish chemist , Jöns Jacob Berzelius in 1838. Recent studies showed , we hardly ever eat straight protein, but get it from foods like meats, fish, and soy, along with fats and carbohydrates in a protein package. Almost all reasonable diets provide enough protein for your body to break down into the building blocks known as amino acids. According to the U.S. Department of Agriculture, the amount of protein foods a person should eat depends on age, sex, and level of physical activity. Proteins can be categorized into two types: complete and incomplete proteins. Complete proteins contain all of the amino acids your body needs and include meat, fish, poultry, dairy, and soy products. Foods that are lacking or are very low in one or more essential amino acids are considered incomplete proteins and include beans, grains, nuts, and vegetable. Along with the two types of proteins, there are three important sub genres of proteins. The first sub genre of protein is Collagen. Collagen is a main structural protein that thrives in the extracellular space in the various connective tissues. There are 5 different types of Collagen Proteins. Type 1 forms skin, tendons vascular ligature, organs and bones. Type 2 forms and helps the cartilage found in bones. Type 3 forms reticular fibers in the body. Type 4 forms the Basal lamina , the epithelium-secreted layer of the basement membrane. And lastly, Type 5 forms cell surfaces, the hair, and placenta. Collagen protein helps and grows all the structural parts of the body. Hemoglobin proteins are globular proteins that carry iron and oxygen in your blood. Hemoglobin is the reason why our blood is red. It is comprised of four protein chains , two alpha chains, and two beta chains. Oxygen binds to these chains of proteins and is used to store oxygen in muscles and tissues of your body. Other than oxygen transport, Hemoglobin can bind and transport other molecules like nitric oxide and carbon monoxide. Hemoglobin contributes to the regulation of blood pressure by distributing nitric oxide through the body and blood stream.The next subgenre of proteins are probably the most important, Enzymes. Enzymes act as catalysts in chemical reactions throughout the entire body. They accelerate the chemical reactions that occur throughout your whole body. The molecules that enzymes act upon are called substrates and the enzymes change the substrates into different molecules known as products. Every single chemical and metabolic processes in the body need enzymes to speed the reactions up fast enough so they can sustain life. Enzymes increase the reaction rate by lowering its activation energy so they can complete the chemical processes. Each of these proteins are useful for life and the process of growing and maintaining a healthy body. The physical structure of the protein is a three dimensional arrangement of atoms in an amino acid-chain molecule. Protein structures range in size from tens to several thousand amino acids. By physical size, proteins are classified as nanoparticles, between 1–100 nm. Very large aggregates can be formed from protein subunits. For example, many thousands of actin molecules assemble into a microfilament.Proteins are polymers, specifically polypeptides formed from sequences of amino acids, the monomers of the polymer. A single amino acid monomer may also be called a residue indicating a repeating unit of a polymer. The amino acid sequence in a protein is determined by DNA. Even a slight change in the amino acid sequence can affect the proteins structure and function. Proteins form by amino acids undergo condensation reactions, in which the amino acids lose one water molecule per reaction in order to attach to one another with a peptide bond. By convention, a chain under 30 amino acids is often identified as a peptide, rather than a protein. A second structure of proteins is a folding along short sections of polypeptide. Described as a A-Helix or a B pleated sheet. To be able to perform their biological function, proteins fold into one or more specific spatial conformations driven by a number of non-covalent interactions such as hydrogen bonding, ionic interactions, Van der Waals forces, and hydrophobic packing. To understand the functions of proteins at a molecular level, it is often necessary to determine their three-dimensional structure. Protein synthesis is the process whereby biological cells generate new proteins; it is balanced by the loss of cellular proteins via degradation or export. Translation, the assembly of amino acids by ribosomes, is an essential part of the biosynthetic pathway, along with generation of messenger RNA, aminoacylation of transfer, co-translational transport, and post-translational modification. Protein biosynthesis is strictly regulated at multiple steps. They occur during transcription and translation. In protein synthesis, a succession of tRNA molecules charged with appropriate amino acids are brought together with an mRNA molecule and matched up by base-pairing through the anticodons of the tRNA with successive codons of the mRNA. The amino acids are then linked together to extend the growing protein chain, and the tRNAs, no longer carrying amino acids, are released. This whole complex of processes is carried out by the ribosome, formed of two main chains of RNA, called ribosomal RNA, and more than 50 different proteins. The ribosome latches onto the end of an mRNA molecule and moves along it, capturing loaded tRNA molecules and joining together their amino acids to form a new protein chain.So, we know how Proteins help our body, we know the different types of proteins and how they help and affect our body, we know the shape of proteins and we know how they are made. But how are proteins digested and put into our body. Protein digestion begins in the stomach with the action of an enzyme that we previously learned about called pepsin. Pepsin is the active protein-digesting enzyme of the stomach. When pepsin acts on the protein molecule, it breaks the bonds that hold the protein molecule together, called peptide bonds. When these bonds are broken, the chains of amino acids linked together form bonds called polypeptides. These polypeptides then move into your small intestine, where digestion will be completed by additional enzymes. In the small intestine, pancreatic enzymes that we previously learned about, called trypsin, chymotrypsin, and carboxypeptidase, really go to work breaking down the polypeptides. These enzymes enter the duodenum via the pancreatic duct. These pancreatic enzymes are helped by the brush border enzymes. brush border enzymes are special enzymes found on the microvilli of the small intestine that complete digestion. The peptide bonds holding the polypeptides together continue to be hydrolyzed, or broken down, and result in smaller units called peptides. Peptides are simply defined as two or more amino acids linked together. Enzymes continue to break down polypeptides and peptides into amino acids. The amino acids are very small, which allow them to be absorbed into the small intestine lining into your bloodstream. Protein is the building block for life. It helps sustain life and build it. Protein is used for almost everything in our body that needs energy. Proteins not only rebuild our muscles, keep our joints working, and fill our body with oxygen, but they keep us alive with energy and nutrients.. Therefore, the molecules are essential to us in an enormous variety of different ways. Much of the fabric of our body is constructed from protein molecules. Muscle, cartilage, ligaments, skin and hair – these are all mainly protein materials. Whether you are a vegetarian or a ‘ meat eater’ you must have protein in your diet. The protein in the food we eat is our main source of the chemical building blocks we need to build our own protein molecules. All around us, proteins show up everywhere we look. It is a complicated mass of amino acids, DNA and many other molecules, but this complicated molecule fuels life!