...Introduction: The ability to isolate and quantify nucleic acids accurately and rapidly is a prerequisite for many of the methods used in biochemistry and molecular biology. The concentration of DNA or RNA in a sample, and its condition, are often estimated by running the sample on an agarose gel. Such concentration estimates are semiquantitative at best and are time-consuming. For a more accurate determination of the concentration of DNA or RNA in a sample, a UV spectrophotometer is commonly used. Spectrophotometry uses the fact that there is a relationship between the absorption of ultraviolet light by DNA/RNA and its concentration in a sample. The absorption maximum of DNA/RNA is approx 260nm. The purity of a solution of DNA can be determined using a comparison of the optical density values of the solution at various wavelengths. For pure DNA, the observed A260/A280 ratio will be near 1.8. Elevated ratios usually indicate the presence of RNA. The A260/A280 ratio is used to assess RNA purity. An A260/A280 ratio of 1.8-2.1 is indicative of highly purified RNA. The 260/280 ratio below 1.8 often signal the presence of a contaminating protein or phenol. Alternatively, protein or phenol contamination is indicated by 230/260 ratios greater than 0.5. Workflow Time 2 days before the lab session During lab session 1:30 pm Task Cell culture 2:00 pm RNA isolation 5:15 pm Spectrophotometric analysis of your sample Work done by Technician Briefing ...
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...BIOL 1F90 Experiment #5 - Archaea: Characterization of Halophiles Student Name: Brittany Barnes Student Number: 5408224 Lab Section: 35 Date Experiment Performed: January 13, 2014 Lab Partners: Kayla Hutchinson Fallon Fersaud Ashley Maulucci Abstract Halobacterium salinarum and Haloferax volcanii come from the domain called Archaea and are considered to be halophilic, because they thrive in extreme environments. In this lab experiment, several tasks took place. In order to be able to observe the colony morphology of both Archaea, they were grown on an agar surface that allowed them to form colonies of characteristic colour and appearance. In order to observe the physiology of both Archaea on the effect of salt concentration, pH, and temperature, they needed to be placed on agar plates and incubated for two weeks. Being incubated for two weeks, allowed the halophilic archaeal cultures to grow. The objective of this experiment was to determine the morphological and biochemical characteristics along with the growth requirements of the halophilic Archaeans; Halobacterium salinarum NRC-1 and Haloferax volcanii DS2. Introduction The domain, Archaea, possesses prokaryotic cells and has a cell wall that contains no peptidoglycan. Archaea contain rRNA that is unique to the Archaea as indicated by the presence of molecular regions. Archaea usually live in extreme environments and include methanogens, extreme halophiles, and hyperthermophiles...
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...Keva Harris 25 February 2016 Biology Lab 27-13 Survey of the Kingdom Fungi Question 1: a. Are hyphae apparent? Yes b. Are the cells motile? Yes Question 2: a. How many species of mold are on the bread? Five b. Is pigment distribution uniformly in each mycelium? If not, where is the pigment concentrated in each mold? No, because the species is not all one color. Concentrated in the sporangium c. What is the adaptive significance of spores forming on ends of apright filaments rather than closer to the protective substrate? It can spread and disperse easier. Question 3: a. Is what structure is the dark pigment of Rhizopus concentrated? zygosporangium b. Is Rhizopus reproducing sexually as well as asexually in the same petri dish? How can you tell? Yes. There were stalks of Rhizopus (asexual) as well as the thick fuzz (sexual). Question 4: What is the relative size of Penicillium hyphae compared with Rhizopus hyphae? The Penicillium hyphae are much smaller. Question 5: a. Do you see chains of yeast cells produced by budding? Yes b. How is the structure of yeast hyphae different from that of molds? Yeast hyphae are short, round, and unicellular. Molds are long and multicellular. Question 6: What is the difference between dikaryotic and diploid cells? In a dikaryotic cell, there are 2 separate nuclei. In a diploid cell, there is one nucleus with 2 sets of chromosomes. Question 7: How many spores would you estimate are...
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...BIOLOGY 10 Introduction to Biology Laboratory Manual Prepared by: KLLabrador Table of Contents |Exercise |Title |Page No. | |1 |Observation and Description |2 | |2 |Formulation, Testing of Hypothesis, |6 | | |and Experimental Design | | |3 |The Use of Models and Controls |9 | |4 |Plant and Animal Tissues |14 | |5 |Cellular Respiration |22 | |6 |Photosynthesis |27 | |7 |Phylogeny and Systematics: Survey of Plant and Animal Families |30 | | ...
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...Three different test tubes were used to test for the effect of alkalinity and temperature on the structure of DNA. The control of the experiment was test tube A because no variables were tested. This test tube was necessary in the experiment because it behaved as a baseline to compare with the results of the experimental variables. Test tube B was exposed to a high temperature (100°C) to observe the effect of high temperatures on DNA structure while test tube C was exposed to an alkaline pH through the use to sodium hydroxide to observe the effect of alkaline environments on DNA structure. To draw conclusions about the effects of these variables, spooling was utilized to observe how much DNA would adhere to a glass rod. DNA can be spooled because of its long structure and its insolubility in ice-cold ethanol; DNA precipitates to a thick, white mass due to the hydrogen bonds between the nucleotides forming. This causes DNA to become packed and easily collected. DNA that is intact will experience a great amount of spooling due to the tight double-helical structure; in contrast, DNA that is damaged will produce lesser amounts of spooling due to the double helix structure degrading. Test tube A experienced a lot of spooling (+++) because the double-helical structure of DNA is stable at room temperature. Test tube B experienced very little spooling (+) due to being exposed to a high temperature (100°C). This is because when DNA is exposed to high temperatures, denaturation occurs;...
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...1) Research is conducted in a lab with Biosafety Level of two. 2) Manage the Hydrochloric acid with extra precaution. 3) If the acid comes in contact with skin or eye, rinse that body area thoroughly with water for fifteen minutes. 4) Wear safety goggles, laboratory gloves, and appropriate clothes at all times in the lab. 5) Before commencing the experiment, make sure the eye wash and safety shower work properly in case of an accident. 6) Keep work area clean and clear of clutter to prevent accidents. 7) Cover the lab surface used with a newspaper to protect it. 8) Using a graduated cylinder, measure 3000 milliliters (mL) (three liters) of distilled water. 9) Form a concentrated solution of 0.01 molarity (M) by adding 4.95 mL of hydrochloric...
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...Sample Essays #2—“The Pupil” by Henry James Sample C In Henry James’ story, “The Pupil” James introduces three main characters, Mrs. Moreen, Morgan Moreen, and Pemberton. All three of these characters interact with each other and it is through this interaction that one can see the character of each. By closely examing “The Pupil” one can see that Henry James creates contrasting characters that work together to tell a story. By first comparing Pemberton to Mrs. Moreen, Henry James is able to compare different classes of society. Mrs. Moreen, who is very rich, as evident through the description of her “fat, jeweled hand” regards money in a offhand, careless way. One gets a sense of this carelessness through Pemberton’s opening thoughts regarding money. While he is focused on his salary, the reader gets the sense that money is of no concern for Mrs. Moreen since she never broaches the subject. Mrs. Moreen represents a class of high society, while Pemperton contrasts this by representing the lower society. Throughout the story, Pemberton’s main focus is about his salary. His worry about his salary represents his, and his societies, concern and appreciation for the value of money, contrast directly with that of Mrs. Moreen’s disregard and unconcerned attitude for money. Thus through these characters and the relationship between them, one gets an idea of the social structure of the time period. Henry James also contrasts Pemberton with Morgan Moreen. Pemberton...
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...Your Full Name: UMUC Biology 102/103 Lab 4: Enzymes INSTRUCTIONS: * On your own and without assistance, complete this Lab 4 Answer Sheet electronically and submit it via the Assignments Folder by the date listed in the Course Schedule (under Syllabus). * To conduct your laboratory exercises, use the Laboratory Manual located under Course Content. Read the introduction and the directions for each exercise/experiment carefully before completing the exercises/experiments and answering the questions. * Save your Lab 4 Answer Sheet in the following format: LastName_Lab4 (e.g., Smith_Lab4). * You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility. Pre-Lab Questions 1. How could you test to see if an enzyme was completely saturated during an experiment? - Add more substrate and record the rate. If the rate of the reaction is constant, all the enzymes are saturated. 2. List three conditions that would alter the activity of an enzyme. Be specific with your explanation. * Temperature – Cold temperature will cause the enzyme to work slow, hot temperature will cause the enzyme to increase the movement making it less stable. * PH – Difference in range in the PH scale can alter the shape of the enzyme’s active site * Concentration Of Substrate – Less or more of enzymes to substrates ratio will affect the rate of collisions between the two affecting the number of reactions. ...
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...Introduction: The purpose of the experiment was to determine if a lighter concentration of salt would diffuse faster than a lower concentration in an equal amount of water. If the salt concentration is higher then it will diffuse faster because it should reach equilibrium faster. The salt bag dissolving into the waiter in an example of hypertonic osmosis. The water is moving into the membrane to dissolve the salt. Materials: • 2 beakers with 200ml of distilled water • 2 permeable membranes (bags) • 8 grams of salt • 1 graduated cylinder • 1funnel • 2 Total dissolved solids meter (TDS) • 1 pair of safety glasses • 1 digital scale • 1 timer • 4 strands of string Procedure: • Gather materials. • Place 200ml water in each beaker. • Prepair membrane. -soak in water. -blow in opening. -tie one end with string. • Add 20ml of water to each bag. • Weigh salt, add five grams to one bag and three to the other. • Tie the ends with string. • Record TDS of water in the beaker. • Start experiment: -Place salt bags into the beakers and start timer. • Record TDS every minute for five minutes Data/Observations: There were no visual observations of changes in the beakers. Discuss/Conclude: The hypothesis was correct. The beaker with I higher concentration of salt diffused faster as indicated by the higher TDS reading after five minutes, It was almost twice as much TDS than the other beaker. The TDS of the water before the salt was added should have been...
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...Comparing The Resting Heart Rate and Recovery Time Of Males And Females After Physical Activity Devyn Jones 26 September 2014 Biology 140 Section 38 Dr. Maria Gainey Abstract In this study we tested to see whether or not males have a lower resting pulse rate and if males have a faster pulse recovery time after engaging in physical activity. The experiment groups are the males and females of the class. The experiment involves walking up and down a flight of stair s and recoding your pulse rate for a period of time. The average resting pulse for the males was 72 beats/min, and the average resting rate for females was 80. The average percent change was 35.7%, and the mean pulse recovery time is 4 minutes. The experiment only partially supported my hypothesis. Males have a lower resting heart rate than females, however females have a faster pulse recovery time than males. Introduction Cardiovascular fitness is frequently considered the most important aspect of physical fitness. In lieu of this statement, we tested which group, males or females, have a better cardiovascular fitness. I believe that males have a lower resting heart rate than females, and a faster recovery time after a period of exercise. In the experiment two groups will be tested, males, and females, they will undergo the step test, take a series of pulses, and record their results. If my hypothesis is valid then the results will show that males have a lower resting heart rate, and display a faster recovery...
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...Design Lab: Respiration The Effect of Heavy-Duty Exercise on the respiration of Homo Sapiens (Humans) Research Question: What is the effect of heavy-duty exercise (cardiovascular and other activities) on the respiration of humans? Background Information: In this experiment, trials will be conducted consisting of humans run up a set of stairs up and down 3 times as fast as they possibly can in order to put pressure on oxygen need to increase respiration needs. This will test the effect of a set exercise on the respiratory needs of a human. After this, they will have to do a set of 10 push-ups and 15 jumping jacks. If 10 push-ups are not possible, a substitute of 15 curl-ups should be administered instead. Hypothesis: When exercise is complete, the respiratory needs of one human should be significantly higher than it was previous to the exercise. Independent Variable: Human fitness level, exercise set Dependent Variable: How fast the human goes Controlled Variable: Temperature, time for exercise, amount of oxygen in air Materials: * Piece of paper for general observations as well as data recording * 4-6 humans * Timer (ipod, clock, something) * Water (if needed for human) Procedure: 1. Use the stairs next to the Biology classroom, select one human to go first and rotate turns until all humans have gone or until necessary data is gathered 2. Record the rate of exhales of the human (normal breathing) for 30 seconds and any other general...
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...Christian Rodriguez Mrs. Gentry AP Biology September 27, 2015 Lab Abstract Enzymes are proteins produced by living cells. In an enzyme, the substrates bind with the active site of an enzyme, breaking them down into other molecules. Enzymes acts as catalyst which lower the reaction energy and allows it to take place in less time and at lower temperatures. Enzymes can be used in a reaction without actually being used up; therefore, they can be used reversibly. Temperature, salt concentration, substrate concentration, enzyme concentration, and pH can affect enzyme reactions. If the pH is too basic, the enzyme gains (H+) and denaturalizes; likewise if the pH is too acidic, then the enzyme loses (H+) and becomes denaturalized. A major benefit...
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...now). Measure the pH just like in step 4 of the Control Variable Procedure. Try to achieve a pH level of 5 by adding more drops of lemon juice if needed. Test the pH after each drop is added. Step 2: Repeat step 1 for each test tube 3-5. The pH for each test tube should reduce in number and become more acidic. Test tube 3 should be a pH of 4, Test tube 4 should be a pH of 3, and Test tube 5 should be a pH of 2. This all can be achieved by increasing the amount of lemon juice in each test tube. Step 3: Once all the test tubes 2- 5 have the required pH level, add 10 drops of 0.66% catechol substrate to each test tube 1 through 5. Step 4: Once each tube is filled with the required amount of substrate, it is time to add the enzyme. Have one lab partner add 10 drops of catechol oxidase enzyme (potato juice) to each of the test tubes. As they add the enzyme, another partner must follow right behind and invert each tube just like before in step 2 of the Control Variable Procedure. Once the first tube is inverted start a timer for 6 minutes like...
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...Hypothesis: As a group predict that aerobic exercise will consume more glucose because of oxidation phosphorylation which produces more ATP. Thus more reps will be done under this condition. Or in other words stage 1 of the lab will have more reps than stage 2 because there is more energy available. During aerobic respiration the continuous break down of sugar will allow more activity to be done versus anaerobic respiration which will just be able to use the energy it currently has, it will not be able to create more. Could you tell when muscles went into anaerobic resp . what evidence? There was a tight feeling in the muscles along with tension and cramping. The oxygen could not be delivered to the cells quick enough to undergo oxidative phosphorylation and instead underwent anaerobic respiration in which oxygen is not needed. During anaerobic respiration, lactic acid fermentation occurred which causes the formation of lactase build up in the working muscles. This causes pain, stiffness, and fatigue which explains the symptoms experienced in the experiment. Panting was also experienced which occurs as a result of the body paying back the oxygen debt that was lost while lifting. When your muscles run out of oxygen, your muscle cells quickly try to produce ATP using lactic acid fermentation. The buildup of lactic acid causes a painful, burning sensation. Hot feeling after lifting. Explain using cellular respiration. Exercising increases the body’s heat production...
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...In our lab, we were able to witness the process of osmosis and diffusion through dialysis tubing, starch, glucose, iodine, and water. The reason we chose to use these materials is because the dialysis tubing could act as a selective permeable cell membrane to view which molecules are able to pass through and which weren’t. We used the starch, since it is a polymer, and found out that it could not pass though the membrane. We used the glucose, which is a monomer, and found that it was easily able to go into a state of equilibrium with the water. The monomer was able to pass through the dialysis tubing due to its small size and the polymer was not due to its large size. This was what we had predicted in our hypothesis except for the fact that although the glucose did pass through the membrane it did not completely pass through only some of it to create equilibrium. In the starch and iodine solution it was the iodine which was allowed to pass thought the starch was not able to due to its large size further explaining why the water had eventually turned almost clear again compared to its brown looking initial state and the inside of the membrane had turned almost completely blue compared to the clear color it was before. When measuring the glucose both inside and out of the membrane we found that they both had some glucose in it, and although we could not visibly see the changes, it was noticed that the diffusion had occurred and since there was some glucose in each it is safe to...
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