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Proteins in nutrition
Protein and its structure in short
Structure and function of a protein essay
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Recommended: Proteins in nutrition
Introduction
Foods are complex systems composed of different components, among which proteins play important roles in the structure, texture, and stability of many foods (Hemar and others 2001). Protein isolates and their concentrated products are commonly and widely used in the food industry for both their added functionality and their nutritive contributions. The functionality of ingredients is important in preparation, processing, storage, quality and sensory attributes of foods (Culbertson 2007). Aside from these functions, proteins also increase solubility, water-holding capacity, elasticity, gelation, emulsification and foaming (Smith 2003). Protein isolates are generally about 90-95% protein while protein concentrates are about 65 to 70% protein (Thompson and Dinh 2010). The protein concentrates or isolates are added to foodstuffs that lack the inherent properties mentioned above (solubility, gelation, emulsification and foaming). Such foodstuffs include: extruded foods, textured meat products, whipped toppings, and protein-rich drinks (Kinsella, 1994).
The use of a protein concentrate or isolate in a food source is dependent on its functional properties which are influenced by the biochemical nature of the protein and the method of extraction and purification used for its derivation. The structure of the protein is of extreme importance in its ability to function in food system. The amino acid sequence of a protein determines the protein folding and three dimensional (3D) appearances. Additionally, the quaternary structure, defined by the number of subunits and the formation of oligometric unit, along with the 3D structure is very important to the overall functionality of a protein concentrate or isolates (...
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Protein Structure and Molecular Enzymology 1547(2): 339-350.
Schokker EP, Singh H. Pinder DN, Creamer LK. 2000. Heat-induced aggregation of β-
lactoglobulin AB at pH 2.5 as influenced by ionic strength and protein concentration.
Intl Dairy Jour 10(12): 233-240.
Singh R, Singh G, Chanhan GS. 2000. Nutritional evaluation of soy-fortified biscuits. J
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The Effect of Temperature on an Enzyme's Ability to Break Down Fat Aim: To investigate the effect of temperature on an enzyme’s (lipase) ability to break down fat. Hypothesis: The graph below shows the rate increasing as the enzymes get closer to their optimum temperature (around 35 degrees Celsius) from room temperature. The enzyme particles are moving quicker because the temperature increases so more collisions and reactions occur between the enzymes and the substrate molecules. After this the graph shows the rate decreasing as the enzymes are past their optimum temperature (higher than). They are getting exposed to temperatures that are too hot and so the proteins are being destroyed.
Protein from whole food has been around since the creation of the world and the times of the hunter-gatherers. Those ages didn’t have whey protein isolate, powdered casein protein, or any of those variations. They just had meat, nuts, veggies, and fruits. The biggest advantage that whole foods have over protein powder is that they stimulate the body’s metabolism more and take more time to be digested and absorbed than shakes.
Abstract/Summary: “Proteins account for more than 50% of the dry weight of most cells, and they are instrumental in almost everything organisms do” (Campbell, 1999). The significance of proteins to the continuation of our biological systems is undeniable, and a study of how to quantify proteins seems an appropriate introduction to our studies of biology. In order to study proteins we must first know how to separate then quantify the amount using basic principles of experimental design such as a standard curve. In this experiment we wish to quantify the amount of previously extracted protein by measuring the absorbance of the unknown amount and determining its concentration by overlaying it against a standard curve of the absorbance of known concentrations of the protein. We used the dye agent Bradford Protein Assay to get an absorbance of 0.078, 0.143, 0.393, 0.473, and 0.527 at the protein’s respective concentrations of 0.28, 0.56, 0.84, 1.12, and 1.40 mg/mL. When a best-fit line was applied to the standard curve, and the absorbance of our unknown concentration (0.317 A) plotted, we estimated a concentration of around 0.84 mg/mL of protein. Our calculations indicated a quantity of 168 mg of protein, which was an approximately 8.96% yield of the projected 1875 mg that was expected. Errors that may have led to this small yield percentage may have stemmed from our previous lab and our initial attempts to extract the desired amount of protein.
By Molecular Approaches." Journal Of Dairy Science 96.8 (2013): 4928-4937. Academic Search Complete. Web. 12 Nov. 2013.
Sequence and structural proteomics involve the large scale analysis of protein structure. Comparison among the sequence and structure of the protein enable the identification on the function of newly discovered genes (Proteoconsult, n.d.). It consists of two parallel goals which one of the goals is to determine three-dimensional structures of proteins. Determine the structure of the protein help to modeled many other structures by using computational techniques (Christendat et al., 2000). This approach is useful in phylogenetic distribution of folds and structural features of proteins (Christendat et al., 2000). Nuclear magnetic resonance (NMR) spectroscopy is one of the techniques that provide experimental data for those initiatives. It is best applied to proteins which are smaller than 250 amino acids (Yee et al., 2001). Although it is limited by size constraints and also lengthy data collection and analysis time, it is still recommended as it can deliver strong results. There are two types of NMR which are one-dimensional NMR and two-dimensional NMR. One-dimensional NMR provides enough information for assessing the folding properties of proteins (Rehm, Huber & Holak, 2002). It also helps to identify a mixture of folded and unfolded protein by observing both signal dispersion and prominent peak. Observation in one-dimensional spectrum also obtains information on molecular weight and aggregation of molecule under investigation. In spite of this, two-dimensional NMR are used for screening that reveal structural include binding, properties of proteins. It also provides important information for optimizing conditions for protein constructs that are amenable to structural studies (Rehm et al., 2002). NMR is a powerful tool which it w...
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).
About 20% of the human body is made up of protein. Because your body doesn’t store protein, it’s important to get enough from your diet each day.
Ice structuring proteins are natural products that form part of a normal diet through their occurrence at high concentration in fish and vegetables. Their diversity and various activities show that the proteins are intriguing parts for use in preserving the quality of foods during chilling frozen storage. Large ice crystals destroy the texture and taste of ice cream. So, use of ice structuring protein is suggested as natural ice crystal growth inhibitor in such products. However, selection of ice structuring protein is based on its easy availability, its changes in certain chemical properties during processing of products, its taste and its related impact on food and food properties, safety and cost.
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. Because the ordered collection of molecules in a crystal can only form if all of the molecular units are the same, the discovery that proteins could be crystallized proved that even large proteins have distinct chemical structures. This deduction completely transformed the understanding of proteins and their respective functions. It is important to investigate how a series of amino acids in a polypeptide chain is translated into a three-dimensional protein structure. There are five general topics related to this process: the structure of a protein is determined by its amino acid sequence, the role of a protein is dependent on its unique structure, an isolated protein typically exists in a small number of stable forms, non-covalent interactions are the most important stabilizing forces in a protein structure, and there are structural patterns that aid in explaining and understanding protein architecture.
Since prehistory, food additives have been added to food. Food additives are substance, other than a basic foodstuff, that are added to the product to serve a technological or sensory function. Although basic food does not include food additives, a number of additives are generally added to process the food. For example to maintain taste, to enhance the appearance or prevent food perishability, and bacterial degradation. Today, more than 2500 additives are used to process the food (A.L. Branen, Davidson, Salminen, & Thorngate, 2001). Some customers regard the use of food additives, especially chemical produced ones. Food additives are unnatural, unhealthy or even a public risk according to those customers (Bearth, Cousin, & Siegrist, 2014). This article will explained the risk, and benefits of food additives.
with growth. Protein are found in animals, products like red meat, fish, cheese, milk, and eggs.
Skim milk is obtained as a by-product of cream separation from whole milk. Due to its negligible fat content (0.02%, compared to 4.0% in whole milk) and hence unpalatability, skim milk was previously considered unsuitable for human consumption and hence used as an animal feed, the advent of spray drying led to its wide utilization as skim milk powder; the process allows for shelf life extension and economical transportation due to the reduction in weight and volume. Skim milk powder has been incorporated into many processed food products such as soups, sauces, bakery and confectionery products, and recombined evaporated milk. A wide range of milk protein products can also be produced from skim milk by varying the processing conditio...
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. The 3D structure is referred to as the secondary structure. There is also a tertiary structure, which is formed by the long-range interactions of the amino acids. Protein function is directly dependent on this 3D structure.
There are four main levels of a protein, which make up its native conformation. The first level, primary structure, is just the basic order of all the amino acids. The amino acids are held together by strong peptide bonds. The next level of protein organization is the secondary structure. This is where the primary structure is repeated folded so that it takes up less space. There are two types of folding, the first of which is beta-pleated sheets, where the primary structure would resemble continuous spikes forming a horizontal strip. The seco...
Food manufacturers use chemical in food processing because of huge economical profit. It is always cheaper to make low quality food rather than healthy food. Food manufacturers’ objectives are to find cheap methods to gain higher profit. The application of techniques such as pasteurization, fermenting and pickling are often use in food companies to prevent food from spoiling ahead of time. Their intention is to stock the food for a long period of time without worrying about early deterioration that can lead to major financial loss. Food companies use antibiotics in chicken, and steroids in cow to stimulate their growth. In an experiment, it was shown that injection of growth hormone in cow improves and stimulates milk production (Baldwin, 1995). Companies’...