One of the most primitive actions known is the consumption of lactose, (milk), from the mother after birth. Mammals have an innate predisposition towards this consumption, as it is their main source of energy. Most mammals lose the ability to digest lactose shortly after their birth. The ability to digest lactose is determined by the presence of an enzyme called lactase, which is found in the lining of the small intestine. An enzyme is a small molecule or group of molecules that act as a catalyst (catalyst being defined as a molecule that binds to the original reactant and lowers the amount of energy needed to break apart the original molecule to obtain energy) in breaking apart the lactose molecule. In mammals, the lactase enzyme is present …show more content…
at birth, and then the production of this enzyme is discontinued, creating a common condition known as lactose intolerance. Humans have evolved over time, and in certain populations from around the world there has been a change in the genetic makeup. This change eliminates the genetic marker that tells the body to discontinue the production of lactase. This deletion allows for the individual to continue consumption of lactose for the rest of his or her life. The study of lactose and lactase reaction is important in terms of biology, specifically human physiology, because of the variance in the presence of lactase.
For example, if a person had been able to consume lactose products for their life with no problems, but in an unfortunate event had to have a portion of his or her small intestine removed, there would be a change in the number of present lactase enzymes in the stomach. Because the lactase enzyme is stored in the small intestine, the person may now experience lactose intolerance due to the decrease in the presence of lactase. Knowing where the lactase enzyme is stored can aid physicians in understanding what will happen after a procedure or the introduction of a new medication. The experiment was conducted to determine the optimal ph of lactose required to produce the maximum amount of glucose. It was predicted that the optimal ph of lactose would be most efficient at lactose ph 6, and that the lower the ph, the amount of glucose produced would increase …show more content…
gradually. The materials required for the experiment include one pair of laboratory grade safety goggles, 8 mini-microfuge tubes, 2mL of lactose at ph 4, 2mL of ph 6 lactose, 2mL of ph 8 lactose, 2mL of ph9 lactose, 5 miniature pipets, 4mL of lactase enzyme suspension, one paper towel, one permanent marker, 8 glucose test strips, glucose color cart (should be found on side of container,) and one timer. The procedure began by obtaining a paper towel approximately 12 inches long. The Sharpie marker was then used to divide the paper towel into an 8X2 grid, and to label the paper towel as following Once this was completed, the individual mini-microfuge tubes were labeled as following: two labeled 4, labeled 6, two labeled 8, and two labeled 9.
These labels indicated the lactose solution that was be placed into the mini-microfuge tubes. The varying lactose ph solutions were obtained. The four miniature pipets were then used, (one per solution,) to add 1mL of the solution to the corresponding mini-microfuge tubes. When this step is completed there were two mini-microfuge tubes that matched the paper towel. Then, once all of the solutions contained their respective lactose solutions, 0.5mL of the lactase enzyme suspension was added to the first mini-microfuge tube labeled LPH4 on the paper towel, and 4 on the microfuge tube. As soon as the lactase enzyme suspension was added to the mini-microfuge tube, the timer was started in stopwatch mode (increasing.) When the timer reached 7 minutes and 30 seconds, the glucose test strip was dipped into the created solution in the mini-microfuge tube for 2 seconds (keep timer going, as the timer is also needed for the glucose strip. Once the two seconds had elapsed, the test strip was immediately removed, and the excess solution was wiped gently on the side of the mini-microfuge tube. The timer was continued for 30 addition seconds. Once the timer reached 7:32 (the extra two seconds accounting for the glucose dip), the test strip was then compared the glucose test strip color chart that is found on the side of the glucose test strip
container. The color that it most closely matched indicated how much glucose was created ( measured in mg/dL by the glucose test strip) when the varying lactose ph solutions reacted with the added lactase enzyme suspension. Experiment one aimed to determine the substance that produced the most amount of glucose. The table below shows that milk, formula, and lactose all produced at least 250 mg/dL of glucose when reacted with the lactase enzyme. The second column shows that every substance excluding the infant formula and glucose did not produce any glucose when reacted with water. It has to be taken into consideration that glucose test strips measured the total glucose, not just reaction produced glucose. The 100 mg/dL of glucose that appear in the second column are the result of added glucose into the formula to provide even more energy for the quickly growing infant. The same concept is applied to the glucose that is visible in the second column was used as a control. This was necessary because it acted as a reminder that the glucose test strips measure the total amount of glucose found in the solution and not just the produced glucose. The lab did not test glucose and lactase because it is assumed that the person running the experiment knows that the lactase enzyme is used a catalyst to break down lactose molecules into glucose. Testing the reaction of a product and the reactant is not going to show any relevant information. The same is true for the water and water reaction. When a substance is added to itself, it is assumed that there is not going to be a reaction, thus the water + water reaction was not tested for glucose production. Experiment two was designed with the intent of finding the optimal ph for the reaction of lactose and the lactase enzyme. It was predicted that the optimal range for lactose would be around 6, and that a minute reaction would be visible at ph 4, ph 8, and ph 9. In the table below it is clear that there is an optimal range for lactose and lactase reactions to occur, as ph 6 was the only one that had a measurable glucose product. The different ph values were each tested twice to ensure that the data collected was accurate. The ph values that were picked were pre-determined by the available supplies on the day of the experiment, and the day prior, when the experiment was planned. The objective of the first experiment was to determine the substance that produced the most glucose when the lactase enzyme was added. The experiment showed that the infant formula and the lactose solution both produced glucose (both solutions created approximately 250 mg/dl of glucose during the reaction.) This is indicative of the enzyme aiding in the catalytic reaction, however, if one were to take the infant formula and look at the nutrition label, he or she would find that there is 100 mg/dL of glucose found in the formula to begin. This is important to note because the glucose test strips do not measure the produced glucose only, but the total amount of glucose found in the solution. Milk did also have a reaction, but the reaction was not as high as the pure lactose. This was due to the wide array of other substances that are found in the milk. There are other components like water and essential vitamins and minerals. This created a differential in the reaction because there was less of the reactants to begin with. One thing that could be changed about this experiment was the testing. To ensure that the data would have been accurate and not just a fluke would be to test each of the mini-microfuge tubes twice. This would ensure that the numbers that were observed on the first test were accurate and not mis-tests. This experiment was necessary for the development of the second experiment because the first experiment lead to the decision to use the lactase as the main test substance in the second. The second experiment aimed to determine the optimal ph of lactose (optimal meaning the one that would produce the most glucose when reacted with the lactase enzyme.) It was predicted that the lactose with a ph of 6 would have the most glucose production, and that the other lactose ph solutions would have increased or decreased results dependent on the ph level (the highest ph solutions having the lowest glucose production levels, and the lower ones having higher glucose production levels.) The hypothesis was proven to be correct and incorrect. The hypothesis was correct in the sense that lactose ph 6 solution did have the highest level of glucose production, but the hypothesis was incorrect because the lactose solutions with ph values of 4, 8, and 9, there was no glucose produced. This is incorrect because it was predicted that the solutions varying in ph would produce more glucose as the ph decreased. The results showed that the lactose solution of ph 6 was the only one to create any glucose when it reacted with the lactase enzyme. This was crucial to the understanding of the human digestive system because it lead to the discovery of the average ph of the human stomach. Without the ph at the level it is, the human body would not be able to effectively use the energy from lactose after birth and beyond because the enzyme does not work. This indicates that there is no effective way to break the bond of the lactose to form glucose. The experiment conducted had a two major flaws. One, the data collected should have been consistent in the lactose ph 6 column, but instead there was a 125 (mg/dL) difference in the glucose level. This could have easily been human error during the experiment. To eliminate this, a third trial should be conducted to confirm or negate the date found in trials one and two. The experiment only included four of the 15 ph values. To accurately test the overall glucose production of lactose at varying ph, it would be of ones best interest to conduct and experiment that measured the glucose production of lactose with ph values around the ph 6 where it is known that glucose production occurs (Ph levels of 5 and 7 would be the most beneficial because it would determine if any reaction would occur near ph 6.) This is beneficial because if a persons stomach acid is off by one point, or the acidity of a gallon of milk has changed, the reaction is going to be different. A different ph could determine how much energy an infant gets from their formula. All in the all the experiment did prove a portion of our hypothesis to be correct, as well as nullifying another part of the hypothesis.
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
After conducting this experiment and collecting the data I would have to say that the optimal temperature for enzyme activity would have to be room temperature which in my experiment was thirty-four degrees Celsius. I came to this answer because the glucose test strip showed that at room temperature there was more glucose concentration that at either of the other temperatures. Due to temperature extremes in the boiling water the enzymes could no longer function because the breakdown of lactose stopped. The cold water also hindered the breakdown of the lactose but as the water warmed the enzymes were more active which can be seen in the results for the cold water at 20 minutes B. Describe the relationship between pH and the enzymatic activity of lactase.
Living organisms undergo chemical reactions with the help of unique proteins known as enzymes. Enzymes significantly assist in these processes by accelerating the rate of reaction in order to maintain life in the organism. Without enzymes, an organism would not be able to survive as long, because its chemical reactions would be too slow to prolong life. The properties and functions of enzymes during chemical reactions can help analyze the activity of the specific enzyme catalase, which can be found in bovine liver and yeast. Our hypothesis regarding enzyme activity is that the aspects of biology and environmental factors contribute to the different enzyme activities between bovine liver and yeast.
Lactase is an enzyme found in the digestive system. It is essential to the complete digestion of sugar in whole milk and milk products. Lactase specifically breaks down lactose, a complex sugar. Lactase cannot be absorbed by the body unless it is broken down by lactase into glucose and galactose. According to webMD, “Lacking lactase in their intestines, a person consuming dairy products may experience the symptoms of lactose intolerance…Abdominal cramping, flatulence (gas) and diarrhea can occur when a lactose intolerant person consumes milk products.” ("Lactase Enzyme oral : Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD", n.d.) Lactase is not recommended for use in CHILDREN younger than 4 years of age. Safety and effectiveness in this age group have not been confirmed. (Kluwer, 2014)
... determine lactose levels. Maybe a lactose quotient could be developed and printed on lactose based products to indicate their relative impact on lactose intolerant people. I think this would be a valuable service to lactose intolerant people in choosing products that contain considerable lactose but have different digestibility factors because of lactase or other additives. I believe study should focus on two major areas. First, alternate methods of processing milk products should be explored, such as making yogurts, cheeses and low-lactose products, and adding lactase to unadulterated milk products to help lactose digestion. Second, alternatives to foods containing lactose should be studied and promoted. This is especially important in food relief programs where our current efforts of sending high- milk diets to hungry people seem wasteful as well as dangerous.
Lipid metabolism is one source of energy for the human body. We eat food containing one form of lipids, triacylglycerols. Before starting lipid metyabolism, these fats get broken down into droplets by bile salts.Triacylglycerols can be broken into fatty acids plus glycerol via hydrolysis with the help of the pancreatic lipase enzymen and then get used by cells for energy by breaking down even further. Once the pancreas and cells have enough energy and don’t need to absorb anymore, fatty acids get synthesized back into triacylgleryols. The excess triacylglycerols get stored in adipose tissue. Excess storage leads to weight gain and obesity.
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).
According to the graph on amylase activity at various enzyme concentration (graph 1), the increase of enzyme dilution results in a slower decrease of amylose percentage. Looking at the graph, the amylose percentage decreases at a fast rate with the undiluted enzyme. However, the enzyme dilution with a concentration of 1:3 decreased at a slow rate over time. Additionally, the higher the enzyme dilution, the higher the amylose percentage. For example, in the graph it can be seen that the enzyme dilution with a 1:9 concentration increased over time. However, there is a drastic increase after four minutes, but this is most likely a result of the error that was encountered during the experiment. The undiluted enzyme and the enzyme dilution had a low amylose percentage because there was high enzyme activity. Also, there was an increase in amylose percentage with the enzyme dilution with a 1: 9 concentrations because there was low enzyme activity.
Alkaline Phosphatase (APase) is an important enzyme in pre-diagnostic treatments making it an intensely studied enzyme. In order to fully understand the biochemical properties of enzymes, a kinetic explanation is essential. The kinetic assessment allows for a mechanism on how the enzyme functions. The experiment performed outlines the kinetic assessment for the purification of APase, which was purified in latter experiments through the lysis of E.coli’s bacterial cell wall. This kinetic experiment exploits the catalytic process of APase; APase catalyzes a hydrolysis reaction to produce an inorganic phosphate and alcohol via an intermediate complex.1 Using the Michaelis-Menton model for kinetic characteristics, the kinetic values of APase were found by evaluating the enzymatic rate using a paranitrophenyl phosphate (PNPP) substrate. This model uses an equation to describe enzymatic rates, by relating the
In biology class, we were learning about enzymes. Enzymes are proteins that help catalyze chemical reactions in our bodies. In the lab, we were testing the relationship between the enzyme catalase and the rate of a chemical reaction. We predicted that if there was a higher percentage of enzyme concentration, then the rate of chemical reaction would increase or it would take less time. We placed 1 ml of hydrogen peroxide into four depressions. Underneath the first depression, we place 1 ml of 100% catalase and make 50% dilution with 0.5 ml of water. We take 50% of that solution and dilute with 0.5 ml of water and we repeat it two more times. there were four depressions filled with catalase: 100%, 50%, 25% , 12.5 % with the last three diluted
In dairy products and in milk, there is a sugar known as lactose. In order to digest this sugar, you need the necessary enzyme. There are several different reasons for the inability to digest lactose: primary lactase deficiency, secondary lactase deficiency, congenital lactase deficiency, and developmental lactase deficiency. Cases dealing with primary lactase deficiency are most common. As babies, there are normally more lactase enzymes produced than needed in order to digest lactose. “Worldwide, most humans lose 90% to 95% of birth lactase levels by early childhood, followed by a continuing decline during the course of a lifetime,” (Thorn). By the time children reach about three years old, the production of lactase significantly drops. In some...
The tubes of E. coli in the phenol red lactose broth one with and the other without mineral oil on top were reddish pink, meaning that the pH was alkaline. That would then mean E. coli can not utilize lactose. However, it is know that E. coli can utilize lactose (BioCoach Activity). The E. coli in a phenol red glucose broth with mineral oil on top produced a yellow color meaning it had a low pH and thus created an acid. There was also gas in the tube which meant that it produced a gas. The E. coli in a phenol red glucose broth without mineral oil was red, that would indicate that an acid was not produced. There was also no gas that was produced.
The lac operon is a transcriptional control of lactose metabolism in bacteria. The operon contains three transcriptional genes, lac Z, lac Y and lac A, which encodes for β-galactosidase, permease and transacetylase respectively. Lac P and lac O copes for the lac promoter and the lac operator, essential to the functioning of this operon. β-galactosidase converts lactose to allolatose, while permease allow lactose to be transported into the cell. Transacetylase does not have a role in lactose usage. In the absence of lactose, there is no allolactose, converted from lactose by β-galactosidase, to the active regulatory repressor, and thus the repressor binds to the operator and transcription is inhibited, as the RNA polymerase bound to the promoter is blocked. In the presence of lactose, allolactose binds to the repressor, rendering it inactive and unable to bind to the operator, allowing the transcription of the three structural genes.
Without enzymes, reactions wouldn’t occur and living organisms would die. For instance, the enzyme in the stomach breaks down large molecules to smaller molecules to absorb nutrition faster. Researchers experimented with enzyme activity with a potato extract. Researchers will test enzyme activity by increasing and decreasing pH levels, lowering and increasing temperature, and substrate concentration effects. In the first experiment, researchers hypothesized whether different pH levels would change how much Benzoquinone are created and how will the enzymes function in neutral pH levels than higher and lower levels. Researchers used potato extract and different levels of pH to test their hypothesis. In addition, researchers questioned at what temperature does the greatest amount of potato extract enzyme activity take place in. Researchers then hypothesized that the results would indicate the greatest amount of potato enzyme activity level will take place in room temperature. In this experiment, researchers used potato extract and different temperature levels to test the hypothesis. Moreover, researchers wanted to test the color intensity scale and how specific catechol oxidase is for catechol. In this experiment, researchers used dH2O, catechol solution, hydroquinone, and potato extract. Lastly, researchers tested the substrate concentration and how it has an effect on enzyme activity. In this experiment researchers used different measurements of catechol and 1cm of potato extract. Researchers hypothesized that the increase o substrate would level out the enzyme activity
Undigested lactose accumulates in the lumen of the small intestine because there is no mechanism for its uptake. This results in osmosis of fluid into the lumen.