Jonathan+D+sf

=Logged in to grade at 6:14pm - observed the history of the edits to page - showing project had been completed up until 1pm today (past the due date & time)= = = =UV Light, Bad or Good?=

Question/Problem: Can prolonged exposure to ultra-violet kill off groups of yeast colonies?
===Hypothesis: I hypothesize that prolonged exposure of UV light on the yeast colonies will cause them to die off, since prolonged exposure to UV light is generally harmful to any type of organic species. ===

__Materials Needed__

 * 1) One Vernier LabQuest PDA/Interface )
 * 2) One Dissolved Oxygen Probe
 * 3) One "Zilla" 50 UVB, 18" T8 Fluorescent Bulb (recommend getting a longer one, since the 18" didn't go across the plastic tub)
 * 4) One box of "CareOne" Disposable Gloves,
 * 5) At least 56 glass jars, each able to hold about 150 mL
 * 6) One 21½ in x 15 1/5 in, 8½ in deep plastic container
 * 7) A warm area, to store the yeast colonies so they will be able to grow, an incubator would work for this
 * 8) A dark/dim area to perform the experimentation. (A darkroom, that is/was used for old photo developments would probably be the most ideal area for an experiment such as this, the dark room needs to be at least at room temperature)
 * 9) One watch
 * 10) One ruler and one roll of measurement tape
 * 11) A notebook
 * 12) Pencil and a marker
 * 13) Seven 6 in x 6 in carton trays (They came with the glass jars that were purchased, the experimenter should be able to fit four glass jars in each)
 * 14) Two 16 13/16 x 5 6/16 in wooden boards (If the experimenter uses the 18" UVB)
 * 15) At least 60 rubber bands, being only 3in to 2½ in diameter.
 * 16) Plastic Wrap (Any brand will do), plastic wrap that clings will help with sealing the glass jars.
 * 17) Dissolved Oxygen Probe's D.O. electrode (Potassium Chloride) container full.
 * 18) One "Flinn Scientific" Inc. Sodium Sulfate solution container (Needed if the experimenter needs to recalibrate the Oxygen probe)
 * 19) Tin foil (Any brand will do), need only a few feet of it. (around 3 - 5 feet, the experimenter does not need a large amount of it anyway)
 * 20) One 5mL dipper, One 1mL dipper and one 15mL dipper
 * 21) 1 Gallon of distilled water
 * 22) Three pounds of sugar (depending on the amount of trials the experimenter needs to complete)
 * 23) One measurement cup, must at least be able to measure one cup of water.
 * 24) Four containers of "Fleischmann's BreadMachine Yeast", 113 g.
 * 25) One roll of paper towels. (Brand does not matter)
 * 26) One dropper

__Experimental Procedure__

 * 1) Set out all 56 glass containers, set out each of the measurement dippers, one of the four yeast containers, set out the gallon of distilled water, the measurement cup, and one pound of sugar.
 * 2) Take the 5mL dipper and scoop up 4g of sugar and dump it into one glass of the 56 glass containers, do this for all of them.
 * 3) Take the 1mL dipper and scoop up 1g of yeast and dump it into each of the glasses. (1g of yeast for each jar)
 * 4) Take the distilled water and pour about 1 cup of its contents into the measurement cup.
 * 5) Take the 15mL dipper and scoop up 10g of water (or just fill up the whole dipper with water) and dump it into each of the containers.
 * 6) Once you have added sugar, yeast, and water into each of the glass jars, you are to take about 6in's of the plastic wrap and wrap it around the top of the glass container and secure it with a rubber band.
 * 7) Once all of the 56 jars have been secured with the yeast growing inside of it, you are to place 28 of them into the plastic containers, then using the 6x6 carton trays make like a roof over them, then place the other 28 jars on top of the trays.
 * 8) Place the plastic container in a warm area for 24 hours. (If you use an incubator, skip step 7 and just place the jars inside of the incubator and set the temperature to 72 degrees)
 * 9) Repeat steps 1-8 for each two trials, since you require 28 jars per trial.
 * 10) Once 24 hours have passed, set out the T8 Florescent UVB, the vernier, and the oxygen probe in the area you wish to experiment. Along with moving the tub containing all of the glass jars to that area.
 * 11) Before beginning the each trial, take the Dissolved Oxygen probe's membrane cap off and use the dropper to drop one mL of the Potassium Chloride into the membrane cap, once dropped, screw the membrane cap back on and wipe off with a paper towel any excess that comes out.
 * 12) Turn on the Vernier, (you will need to plug it in) and plug the Dissolved Oxygen probe into one of its Channel slots.
 * 13) Take out all of the glass jars, separate them 28/28, and layout all of the carton trays.
 * 14) Label the carton trays with the marker, "Control", "1", "2", "3", "4", "5", and "6".
 * 15) Place four glass jars (Doesn't matter which ones) into the "Control" tray, do this for the remaining trays, only four jars will fit into each tray.
 * 16) Place trays 1 - 6 into the plastic container, do not put the "Control" tray into the tub.
 * 17) If using the 18" UVB, if not skip this step, place the two wooden boards on opposite sides of the plastic container, then rest the 18" UVB across them, push them out as far as you can without the UVB falling, take the tin foil and make a roof over the plastic container. (Plug in the UVB as well)
 * 18) Take the "Control" tray, and place it with in reach of the probe, make sure that you have a data table ready to fill in.
 * 19) Fit the disposable gloves over each of your hands.
 * 20) Take one of the jars from the tray, removing the rubber band and the plastic wrap, take the probe and stir it in the yeast solution for 45 seconds (use the watch).
 * 21) Record the reading on the Vernier PDA, if the reading is not staying on a number, pick the number that is in the middle. (i.e. 2.3, 2.4, 2.5 pick 2.4 if it is between only 2 numbers, just pick one of them)
 * 22) Repeat steps 20 - 21 for the remaining jars in the tray.
 * 23) Repeat steps 20 - 22 for every trial's control data.
 * 24) Turn on the UVB, making note of the time, for tray 1, wait 10 minutes, once 10 minutes have passed, remove a section of the tin foil and slowly pull out tray 1, place the tin foil back over the tub.
 * 25) Place the tray within reach of the probe.
 * 26) Repeat step 22
 * 27) For every 10 minute interval, take out the tray that corresponds to the amount of time that has passed. (i.e. tray "2" is for 20 minutes and tray "6" is for 60 minutes)
 * 28) Once another ten minutes have passed take out the next tray and repeat steps 25 - 26, do this until you have recorded all 28 jars.
 * 29) When you have finished the first trial, move onto the next trial, wipe the Probe clean of any yeast.
 * 30) Repeat this as many times as necessary, keep in mind that you require 24 hours for the yeast to grow.

__Logbook__
12/22/11 - Mrs. Wilson gave me the Vernier and the Dissolved Oxygen probe to use in my experiment.

12/26/11 - I going to have to scrap my first trial, since it's not enough data for one trial, along with that its not worth the wait of 1 hour for each trial.

12/31/11 - I bought an extra 28 glass jars, so I can do two trials a day, since I have a downtime of 24 hours for waiting the yeast colonies to fully grow.

1/7/11 - I was able to finish my last trial, clean up obviously won't be fun, since I drop 4 of the jars onto the floor, shattering them.

1/8/11 - Having to update the wikispaces now, probably would have been better to do this much earlier.__.__

__MSDS__

__Abstract__
The purpose of this experiment was to test the effects of Ultra-violets rays on yeast bacteria, bacteria that is commonly used in bread, wine, and beer making. Yeast bacteria produce ethanol alcohol (C2H5OH) and also give off CO2 as a bi-product. However, the oxygen level was measured in this experiment since, a regular CO2 probe was unavailable. The probe showed that there was a decrease in the oxygen level inside the yeast solution, the level kept decreasing as longer times were recorded. Ultra-Violet light exposure on yeast makes it produce CO2 at a faster rate, even though UV light is harmful to organics.

__Experimental Background__
Experimental Results - Pictures - Figure 1 - Depicts step 20, placing the probe into the yeast solution. Figure 2 - Shows that four of the glass jars are able to fit into one tray. Figure 3 - The plastic container that was used for this experiment was able to hold up to 6 of the carton trays. Figure 4 - Shows the membrane cap being filled with the Potassium Chloride solution. Figure 5 - When the container was being stored for 24 hours, it was placed next to a furnace, which melted a small section of the container.

Conclusion :
- In conclusion of this experiment, the hypothesis that I stated was wrong, since the Ultra-Violet light caused the yeast bacteria to almost quadruple its CO2 output (output was quadrupled in several of the jars that were recorded past the 60 minute mark). Looking at the averages for each trial, it is quite visible that there is a steady decrease in the amount of oxygen left in the yeast solution.

Application :
- In beer and wine making, the brewer relies on the yeast to produce ethanol alcohol to make their products have a stronger, more potent taste to them, however wine making relies more on the alcohol product in the yeast. This experiment however, increased the production of CO2, which is actually required in the making of non-alcoholic beverages, such as fountain drinks.