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The structure and function of proteins aqa biology
How the structure of proteins is related to their functions biology essay
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Proteins
Proteins are the macromolecules of life. Discovered in 1838, proteins are recognized as a large number of superior organic compounds that make up living organisms and are essential to their functioning. The term protein comes from the Greek word “proteies” or “primary”. Proteins have many different properties and function in a variety of ways.
They can function as a building material, in teeth, bones and muscles, and they can serve as enzymes, hormones, and neurotransmitters. Its functions are the most diverse of any family.
Whether found in humans, animals, plants or in single-celled bacteria, proteins are made of units of 20 different amino acids. Proteins consist of macromolecules called polypeptides, made from monomers called amino acids. Proteins have hundreds, thousands, or sometimes even millions of these amino acids. These amino acids are made up of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. Some proteins consist of only single polypeptides. In most cases it involves two or more combined polypeptides, sometimes with other small organic molecules or metal ions.
The most basic level of protein structure, called the primary structure, is the linear sequence of amino acids. Different sequences of the acids along a chain, however, affect the structure of a protein molecule in different ways. Protein’s secondary structure often contains long stretched out chains of amino acids called strands that line up together to make sheets. These are called beta strands and the sheets are called beta-pleated sheets. A protein may contain either or both alpha helices and beta pleated sheets. Alpha helices and beta pleated sheets are joined by less clear structures often grouped together under the name of coil. Some small proteins may be made of coil.
Shape is also important. Proteins are coiled and twisted, giving it a unique shape. The shape depends on the sequence of the amino acids, which can be hydrophilic or hydrophobic. Those that are hydrophilic want contact with water and will be twisted to maximize contact. Those that are hydrophobic are twisted in such a way to minimize contact. Changing one amino acid in the polypeptide sequence can destroy this shape and make the protein function improperly if not at all.
A very important function that proteins can serve are to act as catalysts. Enzymes are organic catalysts ma...
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... cells their shape and as well as parts of the linkages that stick cells together into tissues and organs. So, the sequence of amino acids in all proteins is genetically determined by the sequence of nucleotides in cellular DNA.
So basically Proteins are basic constituents in all living organisms. They are complex molecules composed of amino acid and necessary for the chemical processes that occur in living organisms. Proteins are sometimes referred to as macromolecular polypeptides because they are very large molecules and because the amino acids of which they are composed are joined by peptide bonds. The vast majority of the proteins found in living organisms are composed of only 20 different kinds of amino acids, repeated many times and strung together in a particular order. Each type of protein has its own unique sequence of amino acids. Also each protein makes every living organism different.
Bibliography:
1. Proteins, Lexicon Universal Encyclopedia, 1989 Volume 15, pg.576.
2. www.biotech.imcb.edu.com
3. http://www.faseb.org/protein.html
4. “Proteins”. SceinceDaily.þ2000 þwww.sceincedaily.com
5. “Proteins”. Britannica Online 2000 þwww.britanncia.com
The shape of the protein chains that produce the building blocks and other structures used in life is mostly determined by weak chemical bonds that are easily broken and remade. These chains can shorten, lengthen, and change shape in response to the input or withdrawal of energy. The changes in the chains alter the shape of the protein and can also alter its function or cause it to become either active or inactive. The ATP molecule can bond to one part of a... ... middle of paper ... ...
The primary structure is the sequence of amino acids that make up a polypeptide chain. 20 different amino acids are found in proteins. The exact order of the amino acids in a specific protein is the primary sequence for that protein. [IMAGE] [IMAGE]Protein secondary structure refers to regular, repeated patterns of folding of the protein backbone. The two most common folding patterns are the alpha helix and the beta sheet.
Proteins are one of the main building blocks of the body. They are required for the structure, function, and regulation of the body’s tissues and organs. Even smaller units create proteins; these are called amino acids. There are twenty different types of amino acids, and all twenty are configured in many different chains and sequences, producing differing protein structures and functions. An enzyme is a specialized protein that participates in chemical reactions where they serve as catalysts to speed up said reactions, or reduce the energy of activation, noted as Ea (Mader & Windelspecht).
Background information:. Enzyme Enzymes are protein molecules that act as the biological catalysts. A Catalyst is a molecule which can speed up chemical reactions but remains unchanged at the end of the reaction. Enzymes catalyze most of the metabolic reactions that take place within a living organism. They speed up the metabolic reactions by lowering the amount of energy.
There are nine amino acids that are considered “essential” for health, which we must obtain from our diets since our bodies cannot make them on their own. Some of the roles that amino acids/proteins have include helping to form and maintain muscle mass, providing energy for our cells and brain, helping store away energy for later use in fat stores, making your heart beat, and helping build the foundation of vital organs, including your heart, lungs and even your DNA, and supporting growth/development. Because of its ties to lean muscle mass and satiety in terms of controlling your appetite, protein is especially important as you age.
Protein have connection with amino acid to help in functions of: skin, muscle, hair and bones
n.d. - n.d. Peptides and Proteins. Proteins. Retrieved July 25, 2008, from http://www.cd http://www.cem.msu.edu/reusch/VirtualText/protein2.htm Ophardt, C. E. (2003).
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
When eaten, protein is broken down into amino acids. Proteins and amino acids are used for almost every metabolic process in the body, and are the building blocks for every tissue in your body.
Each protein is a large complex molecule; these molecules are made up of. of a string of amino acids. There are 20 different amino acids that occur naturally to form proteins and they all have the same basic structure. The. The 20 amino acids the body needs can be linked in.
Jim Clark. (2007). The effect of changing conditions in enzyme catalysis. Retrieved on March 6, 2001, from http://www.chemguide.co.uk/organicprops/aminoacids/enzymes2.html
A polypeptide chain is a series of amino acids that are joined by the peptide bonds. Each amino acid in a polypeptide chain is called a residue. It also has polarity because its ends are different. The backbone or main chain is the part of the polypeptide chain that is made up of a regularly repeating part and is rich with the potential for hydrogen-bonding. There is also a variable part, which comprises the distinct side chain. Each residue of the chain has a carbonyl group, which is good hydrogen-bond acceptor, and an NH group, which is a good hydrogen-bond donor. The groups interact with the functional groups of the side chains and each other to stabilize structures. Proteins are polypeptide chains that have 500 to 2,000 amino acid residues. Oligopeptides, or peptides, are made up of small numbers of amino acids. Each protein has a precisely defined, unique amino acid sequence, referred to as its primary structure. The amino acid sequences of proteins are determined by the nucleotide sequences of genes because nucleotides in DNA specify a complimentary sequence in RNA, which specifies the amino acid sequence. Amino acid sequences determine the 3D structures of proteins. An alteration in the amino acid sequence can produce disease and abnormal function. All of the different ways
Protein domains occur in large polypeptides, (proteins that have more than 200 residues). These proteins have two or more globular clusters which in turn have domains composed of 100-200 amino acids. Thus many domains are structurally independent units that have the characteristics of small globular proteins.
If proteins are the building blocks of life, then amino acids are the building blocks of proteins. Plant cells form amino acids from the compounds which the plant draws up from the ground, such as the nitrates and ammonia salts. Animals, however, cannot perform this conversion of simple inorganic substances to amino acids, so they must ingest them in the form of food-- with herbivorous animals consuming plant proteins in vegetables and carnivorous animals consuming animal proteins in the bodies of their prey.
Proteins (macronutrient), which are found in animal products, nuts and beans, they help to build new cells, maintain tissue and synthesis new proteins essential for performing basic bodily functions. Proteins are in abundance in the human body and are present in the outer and inner membranes of all living cells (Dummies, 2018). Proteins are essential for building new cells, maintaining tissue and helping new proteins needed for basic bodily function (