After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid. Place another dry test tube in a 50mL beaker and weigh it. Find a bottle of barium iodide and record the name and molar mass. Then, weight out either anhydrous barium iodide or barium iodide dehydrate into this test tube and dissolve is it in 2 mL of deionized water. Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form.
Explain how the process of blanching is used in the food industry and why a specific temperature is required. -Blanching is used in the food industry to quickly heat products containing peroxidase to denature the proteins in an attempt to stop peroxidase from producing the foul-tasting hydrogen peroxide molecules. A specific temperature is required because the food needs to be heated, but not so much so that it gets cooked, or not so little so that the peroxidase remains
Do an initial Benedict's test on the 15% glucose/1% starch and the beaker solutions for glucose by putting some of the solution and a roughly equal amount of blue Benedict's solution in a test tube, placing the test tube in boiling water for 90 seconds, and observing whether or not the solution changes color from blue. 3. Form a bag out of dialysis tubing by tying off one end, putting in enough 15% glucose/1% starch solution to fill it halfway, and tying off the other end leaving the other half of the bag void of anything (even air). Write down the solution's color. 4.
3. A filtration setup should be used to separate the seaweed from the extract where the filtrate is collected in an evaporated dish. 4. After 2-3 mL of filtrate is collected, the extract should be poured into a beaker in which
Measure 50.0 mL of 2.0 M Sodium Hydroxide, NaOH, solution but DO NOT ADD YET. Click the Collect button to get the initial temperature of the HCl solution. After the first four readings have been recorded at the same temperature, add the NaOH solution. Make sure you have lowered the paper lid to keep from liquid coming out of the cup. Turn the Stirrer on, at a slow to medium speed.
Because Daphnia are ECTOTHERMS (cold-blooded), their body temperature changes with the surrounding environment. Since chemical reactions are speeded up in warmer temps, what would you predict the effect of temperature changes would be on their rate of metabolism (and heart rate)? Chemicals, which enter their bodies, can also change their heart rate by interfering with the chemicals that nerves use to transmit signals. Chemicals that speed up heart rate are known as stimulants, whereas chemicals that slow down the heart rate are known as depressants. HYPOTHESIS : What is the Dependent Variable measured: ______________________________________ What is the Independent Variable used: __________________________________________ Predict the effect of each situation/solution on the heartbeat: Make a Hypothesis for each Cold Water Hot Water 1% Ethanol Sugar Water MATERIALS • 4 Daphnia in culture liquid (per table) • Transfer pipette • a clean depression slide • Compound microscope • a small container for “used” Daphnia PROCEDURE – follow below or the modify to YOUR teacher’s instructions Keep the light for your microscope OFF as much as possible to avoid overheating your Daphnia!
Hydrogen peroxide is a poisonous chemical to all living things. Catalase converts H 2O 2into 2 separate harmless substances, water and oxygen. In this experiment we will be testing the effects of temperature, pH and substrate concentration on Catalase. The optimum pH of catalase is 7 and its optimum temperature is 37 degrees. Aim: To test the effect of change in pH, Temperature and substrate concentration on catalase in liver Hypothesis: we predict the enzyme will have its greatest reaction when it is in its optimum temperature, pH and substrate concentration Risk assessment: * Wear gloves when handling raw liver.
Add 5 mL of copper (II) sulphate solution to a test tube. Add 5 mL of sodium carbonate in another test tube. Record the appearance. 2. Write a hypothesis on what you think will happen when mixed.
This is important as everything in the body has a prime temperature it works at. Enzymes would denature if the body was to overheat and many other problems would occur. The Hypothalamus in the brain is the control centre where is acts as a receiver of messages when temperature changes. It detects the temperature from the blood running through it. The receptors used in negative feedback when it comes to temperature are called thermoreceptors.
Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder. (Take care when measuring this out and adding it to the beaker to avoid any drips and spills.) 2) Heat the mixture gently over a tripod and gauze, STIRRING CONSTANTLY with a glass rod (otherwise the mixture erupts). Allow to simmer (boil gently) for 5 minutes. Steady the beaker using