Protein Thermal Stability Essay

The protein molecules in many foods provide the amino acid building blocks required by our own cells to produce new proteins. To determine whether a sample contains protein, a reagent called Biuret solution is used. Biuret solution contains copper ions. However, the chemical state of the copper ions in Biuret solution causes them to form a chemical complex with the peptide bonds between amino acids (when present), changing the color of the solution. Biuret solution is normally blue, but changes to pink when short peptides are present and to violet when long polypeptides are present.

Temperature controls the speed the enzymes work at. Higher temperatures increase the kinetic energy which increases the chance of collision therefore speeding up the rate of

Proteins are important for the human body. Proteins play many important roles in the body including the structure of enzymes; these are important proteins that help reactions occur in the body, such as releasing from the food we eat. Proteins also function as transport proteins such as hemoglobin; an iron

Proteins are the metabolic workhorses of the cell; they engage in a variety of essential activities ranging from enzymatically catabolizing macromolecular food sources to serving as structural components that maintain cell stability. Maximizing protein function relies on intricate non-covalent interactions occurring on the secondary, tertiary, and quaternary levels that help determine the overall shape of the protein. In their native states, proteins will assume the most energetically favorable configuration. Occasionally however, cells are exposed to exogenous disruptions such as heat stress. Heat Stress can compromise protein three-dimensional structure. Hydrophobic residues tend to be buried in the interior of the protein but when

Hydrogen Bonds – These arise between the R-CO-R and the R-NH-R, and increase the boiling point of the structure of the enzyme as more energy is required to break the intermolecular bonds. This means that the enzyme can function at a higher than normal temperature.

Amino Acids are essential nutrients that are the primary building blocks of proteins found in meat, dairy products, and legumes. Proteins make up 20 percent of the human body, and the amino acids that make up these proteins play a critical

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.

The purpose of this lab experiment was to determine the relationship between temperature and the rate of enzymatic activity in yeast cells. In the lab, the temperature was the independent variable. The temperatures consisted of 6°C, 24°C, 34°C, 46°C. The dependent variable in the experiment was the rate of enzymatic activity in yeast cells. The temperatures were tested by using a LabQuest and pressure probe that tested pressure inside the plastic test tube. LabQuest graphed the data and created a line of best fit that was used to determine the slope of the graph. The slope of the graph represents the rate of enzymatic activity. The slope was found for each temperature in 2 different trials. Then, the rate of enzyme activity (kPa/sec) for each temperature in the 2 trials were averaged. These averages were used to develop a graph that shows the relationship between temperature and the rate of enzyme activity. According to the results of the experiment, as the temperature increases, the rate of enzymatic activity decreases. Each enzyme has its own optimal temperature in which it can function efficiently.

Proteins are molecules containing amino acids, which our body and cells need to keep our bodies functioning properly. Body structure, functions and regulates the body's cells, tissues

Proteins are essential nutrients made up of chains of amino acids that the body uses for energy as well as to function. The two kinds of proteins are animal, and plant proteins. Animal proteins include meat, eggs, poultry, seafood, and dairy products. Most animal proteins are rich in zinc, and heme iron. One of the widely known reasons that many people feel animal proteins are important is because they contain more of a complete set of amino acids.

Heat effects the enzyme activity by speeding up the reaction and/ or completely denatures the enzyme. When the yeast and hydrogen peroxide mixture was put into the 80 degree C, the amount of O2 mL evolved constantly stayed at 0 ml for the complete 10 minutes contrary to the room temperature water in which the amount of O2 evolved increased by about an average of 7 mL for about 6 minutes and then increase by about 1-2 mL. An enzyme denatures with high temperature because heat changes the shape of the active site permanently which causes the enzyme to cease function. On the other hand, a colder temperature will slow the down the enzyme reaction. In 2.4 degree C solution, the amount of 02 evolved by about 1-3 mL every 30 seconds and by 6 min

In this graph we can see, when the temperature is high, the rate of the reaction also increases, but when temperature is too high it denatures the enzyme. In this case enzyme’s activity is changing with increasing the temperature and by this the reacting molecules have more kinetic energy and they move faster and they have a better chance to collide. There is a specific temperature at which enzyme’s activity is the best, and this is known as (Optimum) and this temperature is 37 C (Human body temperature). After this point the temperature continue increasing, the rate of the reaction decrease and the enzyme denature (when the enzyme loses its original shape), this is the cause that enzyme stop working as it cannot bind to the substrate.

The bonds that link the amino acids are strong covalent bonds that endure the heat but the bonds that stabilize the 3D structure (like ovomucin and ovalbumin) are weak hydrogen bonds. When the hydrogen bonds break, the proteins are resolved. When two spread out proteins are in contact,

B) Proteins Proteins are made up of chains of amino acids. Each protein folds into a characteristic three dimensional shape that is essential to its function. They perform a variety of functions in cells and are probably the most diverse macromolecule in living systems. The Biuret test detects the presence of proteins and short peptides (short chains of amino acids). Biuret reagent contains a strong solution of sodium hydroxide (NaOH) and a very small amount of dilute copper sulfate solution. The reagent changes color in the presence of a protein because the amino groups in the amino acids react with the copper ions producing a violet color. A negative result is blue.

They are used in infant formulas, flour, protein isolates, cheeses, drinks, tofu and salami. Infant formulas made from soy proteins serve as an excellent alternative in cases where milk allergies prevent the use of other types of formula. These proteins are deficient in methionine, one of the essential amino acids required by man, and the content of lysine is lower than that of casein, a protein found in milk. In addition to nutritional value, studies have shown that soy protein may play a positive role in several human health concerns such as lowering cholesterol, they have anticarcinogenic effects, and they may help control conditions such as diabetes, digestive tract irritation, and bone and kidney disease (Mendel and Brandon 2001).