Chemical and Physical Processes of Digestion free essay sample

Review Sheet Exercise 8 Chemical and Physical Processes of Digestion NAMEDane Wilson LAB DATE/TIMEaugust 4th Carbohydrate Digestion The following questions refer to Activity 1: Assessing Starch Digestion by Salivary Amylase. 1. At what pH did you see the highest activity of salivary amylase? Why? 7. 0 because that is when the salivary is most effective and it breaks down carbohydrates. 2. How do you know that the amylase did not have any contaminating maltose? We used a negative control to see if there is any amylase in the maltose. . What effect did boiling have an enzyme activity? Why? Boiling denatured the enzyme because it destroys the structure of the protein. 4. Describe the substrate and the subunit product of amylase. The substrate is starch the subunit is reducing sugar. The following questions refer to Activity 2: Assessing Cellulose Digestion. 5. Does amylase use cellulose as a substrate? Explain. No because amylase only works on starch and wont digest cellulose. We will write a custom essay sample on Chemical and Physical Processes of Digestion or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 6. Did freezing have an effect on the activity of amylase? Explain. Freezing does not change the structure of the enzyme so it doesn’t have effect on the activity. 7. Do you think that the bacterial suspension contained the enzyme cellulose (an enzyme that digests cellulose)? Why or why not? Yes I think the bacteria contained cellulase because it specifically digests cellulose. Protein Digestion by Pepsin The following questions refer to Activity 3: Assessing Protein Digestion by Pepsin. 8. What is the substrate of peptidase? Explain, based upon your results. The substrate is a synthetic protein called APNA. . At which pH did you see the highest activity of pepsin? How does this correlate to the location of pepsin in the body? 2, it correlates well with the gastric environment. 10. What effect did boiling have on pepsin? Boiling the pepsin denatures the enzyme. 11. Was there any digested APNA contaminating the pepsin or deionized (DI) water? How can you tell? No there wasn’t any APNA contaminating either the pepsin or deionized water be cause negative spectrophotomer result. 12. What is the substrate in this experiment? What is the usual substrate for pepsin, and what subunits are formed with pepsin activity? APNA the usual is protein and the subunits are amino acids. 13. What was the effect of decreasing the incubation time on the optical density results? Decreasing incubation time causes decreased optical density. 14. What effect would decreased incubation temperature have on pepsin activity? Why? It would cause reduced optical density because the decreased rate of enzymatic. 15. What was the significance of using 37Â °C for the incubation? Because 37 C is body temperature. Fat Digestion by Pancreatic Lipase and the Action of Bile The following questions refer to Activity 4: Assessing Fat Digestion by Pancreatic Lipase and the Action of Bile. 16. Describe the activity of lipase with and without the addition of bile salts. Refer to Chart 4 for pH values. The lipase is more effective with the bile salts. 17. Is the activity of bile a chemical or physical process? Explain. Physical because it breaks up the fat. 18. What pH resulted in the maximum pancreatic lipase activity? 7. 0 How does this optimal pH correlate to the enzyme’s location in the body? It correlates with the duodenum. 19. Explain whether or not we can determine fat hydrolysis in tube 5. Why or why not? We can determine fat hydrolysis because we know the ph and there is no decrease. 20. What is the substrate in this experiment? What subunits does lipase form? The substrate are fats or vegetable oil the subunits formed fatty acids. Physical Process: Mechanisms of Food Propulsion and Mixing The following questions refer to Activity 5: Studying Mechanisms of Food Propulsion and Mixing: Deglutition (Swallowing). 1. Explain the significance of the movement of the tongue during swallowing. Because it prevents water from entering the airway 22. Describe three events that occur during the pharyngeal-esophageal phase of deglutition. The mouth nasopharynx and larynx are blocked the esophageal sphincter relaxes to open the esophagus and food moves through the esophagus by pressure gradients made by peristalsis. 23. What was the time interval that you recorded between the first and second sound?

Nano-Composites

Question: Describe about Nano-composites. Answer: Introduction to Nano-composites In the field of nanotechnology there are various things which are yet unknown or are still in the development phase. The NANCOMPOSITES is also a topic which is still under research and development phase. Nanocomposites are those composites which have the dimension in the nanometric range. Although the preparation process of nanocomposites is difficult to control, yet the importance of it cannot be overlooked. The nanocomposites have provided a great alternative to the monolithic and microcomposites. It is considered that when a particle is made into a size which is known as critical size of that material then it changes the parental properties. This is because as the size decreases the property of interaction at different phases changes and so does the property of the material. In the recent past, various nanocomposites such as carbon nanotubes and polyester have been discovered possessing excellent mechanical, thermal and electric properties which added a new dimension to the field of nanotechnology (Schmidt, 2012). The main advantage of the nanocomposites is that they are environment friendly beside it offers new technology and development day by day. The nano-composites are broadly classified into three groups, and they are as follows: Polymer Matrix Nanocomposites Metal Matrix Nanocomposites Ceramic Matrix Nanocomposites Properties The Nanocomposites possess some amazing properties which can be found in the larger sized or parental components. The properties which the nanocomposites possess are mechanical toughness, chemical stability, high thermal stability and good wear resistance (Gleiter, 2012). However, it also comes to the low toughness of ceramics which have been considered as a stumbling block when it comes to the wider use of nanocomposites in the industry. This limitation of nanocomposites have been overcome by the ceramic matrix nanocomposites which posses higher mechanical properties. The nanocomposites have high strength when we consider either the compressive force or the tension force. Furthermore, the more and more mixing of several materials, the wider the scope of the nano technology becomes (Roy, 2013). Different approaches are followed to find out a new composite which have some unique electrical, mechanical, magnetic, catalytic and optical properties. They have the potential to find out the applications in the field of aerospace and automobile industries. The metal matrix composites and the ceramic matrix nanocomposites shows great challenge to be used in the aerospace and automobile industry, but when it comes to real success, its brings some difficulties. The nanocomposites doesnt have only the advantages to be discussed about, rather it has some disadvantages too, which needs to be discussed. It has some fairly low strength of modulus when it is compared to the ceramic and the metal (Braun, 2011). Conclusion Considering the fact that as the year passes by, researcher are in a search of finding more and more newer technologies which could take over the conventional process of living. The nanocomposite shows the perfect promise to deliver the same and gives an edge to the scientists and researcher working on newer material which posses different properties from their parent. References Roy, R. (2013). Alternative perspectives on "quasi-crystallinity": non-uniformity and nanocomposites. New York, NY: Materials Letters. Schmidt ,D. (2012). New advances in polymer/layered silicate nanocomposites.NC, USA. Gleiter, S. (2012). Materials with ultrafine microstructures: retrospectives and perspectives.Nanostructured Materials., Vol. 1, pp. 1- 19. Braun, T. (2011). Nanoscience and nanotechnology on the balance.Scientometrics, Vol. 38, pp. 21-325.

Students Should Try to Use Sample Orders in Essays

Students Should Try to Use Sample Orders in EssaysStudents enter the world of student life prepared to take advantage of all that the sample orders essay writing society has to offer. They know that when they read about sample orders they will find many things to think about. What students are often unaware of, though, is that when they read a sample orders they are not actually being presented with a proposal for an essay.When a student uses a sample order, they are only receiving the idea for their essay. That is the true form of this writing assignment. They have chosen to read about the sample order and then they will be presented with the idea for their own written assignment.Students know that they will not need to pitch their ideas as essays. They also know that if they do the research necessary to turn their ideas into an essay, they will have to prepare it in some way. Using sample orders and turning those orders into real essays is something that students should do, but the y should also be aware that they will have to prepare those essays before they even begin.This can be done through writing about what ideas they are using in the essay. Students should see to it that their writing does not sound like the essay they are about to write. Even though students know they are writing an essay, they should not sound like an essay they are writing.Students should take the time to consider what they will be using their ideas for. If they are using the sample order to pitch their own ideas, they should make sure that they use proper academic language. They should try to do research on what this and other writing styles look like in the world of academe.They should also understand that when they are presenting themselves to an audience, they should show them that they are a serious writer. They should also understand that they are serious about their essay when they use examples from the public record. They should also understand that they are serious about the ir essays when they choose to submit the writing to professional organizations that specialize in these types of essays.When students see samples of these samples, they should consider the exact writing style they will be using to present themselves as experts in their field. They should take time to understand the use of personal pronouns in the language. They should know how to use the correct adjectives, adverbs, positions, and adverbial phrases.They should take the time to understand the use of formal and informal style. They should use grammar and syntax that they are familiar with. They should be able to use all of these elements when they present themselves as knowledgeable in their field, and they should do so by following the proper style.

A Guide to Masters and Doctoral Comprehensive Exams

A Guide to Masters and Doctoral Comprehensive Exams Graduate students take two sets of comprehensive exams, both masters and doctoral. Yes, it sounds scary. Comprehensive examinations, known as comps, are a source of anxiety for most graduate students. What Is a Comprehensive Examination? A comprehensive examination is just what it sounds like. It is a test that covers a broad base of material. It assesses the students knowledge and capacities to earn a given graduate degree. The exact content varies by graduate program and by degree: masters and doctoral comprehensive exams have similarities but differ in detail, depth, and expectations. Depending on the graduate program and degree, comps could test course knowledge, knowledge of your proposed research area, and general knowledge in the field. This is especially true of doctoral students, who must be prepared to discuss the field at a professional level, citing material from coursework but also classic and current references. When Do You Take Comps? Comps are generally given toward the end of coursework or afterward as a way to determine how well a student is able to synthesize the material, solve problems, and think like a professional. Passing a comprehensive exam lets you move to the next level of study. What Is the Format? Masters and doctoral exams often are written exams, sometimes oral, and sometimes both written and oral. Exams are usually administered in one or more long test periods. For example, in one program written doctoral comprehensive exams are given in two blocks that are each eight hours long on consecutive days. Another program administers a written comp exam to masters students in one period that lasts five hours. Oral exams are more common in doctoral comps, but there are no hard and fast rules. What Is the Masters Comp Exam? Not all masters programs offer or require that students complete comprehensive exams. Some programs require a passing score on a comprehensive exam for entry to the thesis. Other programs use comprehensive exams in place of a thesis. Some programs give students a choice of completing either a comprehensive exam or a thesis. In most cases, masters students are given guidance on what to study. It might be specific lists of readings or sample questions from previous exams. Masters comprehensive exams are generally given to an entire class at once. What Is the Doctoral Comp Exam? Virtually all doctoral programs require that students complete doctoral comps. The exam is the gateway to the dissertation. After passing the comprehensive exam a student can use the title doctoral candidate, which is a label for students who have entered the dissertation phase of doctoral work, the final hurdle to the doctoral degree. Doctoral students often receive much less guidance on how to prepare for comps as compared with masters students. They might get long reading lists, some sample questions from previous exams, and instructions to be familiar with articles published over the past few years in the prominent journals in their field. What If You Dont Pass Your Comps? Graduate students who are unable to pass a programs comprehensive exam are weeded from the graduate program and cannot complete the degree. Graduate programs often allow a student who fails the comprehensive exam another chance to pass. However, most programs send students packing after two failing grades.

Chlorophyll Definition and Role in Photosynthesis

Chlorophyll Definition and Role in Photosynthesis Chlorophyll is the name given to a group of green pigment molecules found in plants, algae, and cyanobacteria. The two most common types of chlorophyll are chlorophyll a, which is a blue-black ester with the chemical formula  C55H72MgN4O5, and chlorophyll b, which is a  dark green ester with the formula C55H70MgN4O6. Other forms of chlorophyll include chlorophyll c1, c2, d, and f. The forms of chlorophyll have different side chains and chemical bonds, but all are characterized by a chlorin pigment ring containing a magnesium ion at its center. Key Takeaways: Chlorophyll Chlorophyll is a green pigment molecule that collects solar energy for photosynthesis. Its actually a family of related molecules, not just one.Chlorophyll is found in plants, algae, cyanobacteria, protists, and a few animals.Although chlorophyll is the most common photosynthetic pigment, there are several others, including the anthocyanins. The word chlorophyll comes from the Greek words chloros, which means green, and phyllon, which means leaf.  Joseph Bienaimà © Caventou and Pierre Joseph Pelletier first isolated and named the molecule in 1817. Chlorophyll is an essential pigment molecule for photosynthesis, the chemical process plants use to absorb and use energy from light. Its also used as a food coloring (E140) and as a deodorizing agent. As a food coloring, chlorophyll is used to add a green color to pasta, the spirit absinthe, and other foods and beverages. As a waxy  organic compound, chlorophyll is not soluble in water. It is mixed with a small amount of oil when its used in food. Also Known As: The alternate spelling for chlorophyll is chlorophyl. Role of Chlorophyll in Photosynthesis The overall balanced equation for photosynthesis is: 6 CO2 6 H2O → C6H12O6 6 O2 where carbon dioxide and water react to produce glucose and oxygen. However, the overall reaction doesnt indicate the complexity of the chemical reactions or the molecules that are involved. Plants and other photosynthetic organisms use chlorophyll to absorb light (usually solar energy) and convert it into chemical energy. Chlorophyll strongly absorbs blue light and also some red light. It poorly absorbs green (reflects it), which is why chlorophyll-rich leaves and algae appear green. In plants, chlorophyll surrounds photosystems in the thylakoid membrane of organelles called chloroplasts, which are concentrated in the leaves of plants. Chlorophyll absorbs light and uses resonance energy transfer to energize reaction centers in photosystem I and photosystem II. This happens when energy from a photon (light) removes an electron from chlorophyll in reaction center P680 of photosystem II. The high energy electron enters an electron transport chain. P700 of photosystem I works with photosystem II, although the source of electrons in this chlorophyll molecule can vary. Electrons that enter the electron transport chain are used to pump hydrogen ions (H) across the thylakoid membrane of the chloroplast. The chemiosmotic potential is used to produce the energy molecule ATP and to reduce NADP to NADPH. NADPH, in turn, is used to reduce carbon dioxide (CO2) into sugars, such as glucose. Other Pigments and Photosynthesis Chlorophyll is the most widely recognized molecule used to collect light for photosynthesis, but its not the only pigment that serves this function. Chlorophyll belongs to a larger class of molecules called anthocyanins. Some anthocyanins function in conjunction with chlorophyll, while others absorb light independently or at a different point of an organisms life cycle. These molecules may protect plants by changing their coloring to make them less attractive as food and less visible to pests. Other anthocyanins absorb light in the green portion of the spectrum, extending the range of light a plant can use. Chlorophyll Biosynthesis Plants make chlorophyll from the molecules glycine and succinyl-CoA. There is an intermediate molecule called protochlorophyllide, which is converted into chlorophyll. In angiosperms, this chemical reaction is light-dependent. These plants are pale if they are grown in darkness because they cant complete the reaction to produce chlorophyll. Algae and non-vascular plants dont require light to synthesize chlorophyll. Protochlorophyllide forms toxic free radicals in plants, so chlorophyll biosynthesis is tightly regulated. If iron, magnesium, or iron are deficient, plants may be unable to synthesize enough chlorophyll, appearing pale or chlorotic. Chlorosis may also be caused by improper pH (acidity or alkalinity) or pathogens or insect attack.

Rhetorical Analysis Essay Example | Topics and Well Written Essays - 1000 words - 4

Rhetorical Analysis - Essay Example There are always the breathless promos ("Nude man found at mall: Film at 11!"). There are always the two amiable chatting anchors, usually a middle-aged man and a somewhat younger woman. There are the younger roving reporters, featured live at various points around the community or nation, where they chat up the anchors. ("Do you know why the man was wearing no clothes, Jim?" "We're working on that, Susan") There's the joking weatherman, the jock sportscaster, and more recently, the health editor and the lifestyle reporter. In a nation of enormous diversity, there's something both comforting and appalling in knowing that no matter where you are, the local news--like the local McDonalds--is always the same. What makes most of these newscasts pernicious is that they are at the same time so influential and so awful--at least in journalistic terms. In recent years, the local newscast has replaced the network evening news and the newspaper alike as the average American's main source of ne ws: A study by the Pew Research Center for the People and the Press in 1996 found that 65 percent of all adults said they regularly watched the local TV news; only 42 percent reported that they did the same with a network newscast. In about two-thirds of all markets, according to another study, the early-evening local news shows attracted better ratings than the network newscasts that followed them--and the local news is on for a longer time. Though local newscasts have been studied far less systematically than the national news, nearly everyone who has examined their content has come away with the same conclusion. For example: A 1995 study of the local news in 50 major markets by the Rocky Mountain Media Watch found that crime and disaster news make up about 53 percent of the news on local newscasts--the grislier the crime, the better. ("Son shoots mother five times with bow and arrow") Fluff--deemed by the study as 'soft news, anchor chatter, teases, and celebrity items"--takes up about 31 percent of the whole newscast, on average (items such as "Girl reunited with dog" or "How to tango"). An informal 1993 survey by The Washington Post of local newscasts on stations in five big cities found the percentage of stories involving crime, sex, disasters, accidents, or public fears running at anywhere from 46 to 74. In its survey, the Post found local newscast obsessed with murders, serial killers, snakebites, spider bites, tornadoes, mudslides, explosions, and satanic activity. A 1990 study published by the Columbia Journalism Review found that 18 of the 32 stories analyzed on local newscasts were inaccurate or misleading, and the station usually made no attempt to correct the mistakes. A report published the same year in the L.A. Reader, following examination of a week's worth of stories in that market, found stations routinely airing PR footage provided by companies with no acknowledgment that this was what was going on. In a 1991 book examining the local news, Making Local News, Phyllis Kaniss found, among other things, that local TV news reporters are more likely to accept their sources' viewpoints than are print reporters. A Chicago reporter looking at "sweeps week" on Los Angeles television found heavily promoted news stories on lesbian nuns, Geraldo Rivera's love life, and sex after 60. As a critic once put it: The worst scandal the local news could ever uncover is itself. Local news didn't start out this way. Until about 1970, local news--with its

Artist Statement (Describe all the photos with the following Essay

Artist Statement (Describe all the photos with the following sugestion) - Essay Example Natural or not, they still share the same colors. The imagery conveys the themes quite clearly since when the images are laid next to one another the colors can easily be seen and compared. Blues and silvers are similar throughout each photo. The framing and composition does not have any affects on the work. Each photo regardless of how the photo is framed contains similar theme since each photo represents life in some way. The photos are very straight forward and do not have too much going on. Each photo is simple and easily portrays the photographed object without having to guess what the object is. The photos are clear and easy to see, which makes the themes easy to figure out. The colors in the photos have many cool earth tones. There are few hot colors. The color creates a soothing affect in the imagery that makes the viewer feel relaxed. Some of the images are very sharp. The images that are taken from a further distance are sharper then images taken close up. The photographer can adjust the lens according to distance to improve the sharpness of the