[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:04.57,Default,,0000,0000,0000,,Experiment OB3A, To test a variety of foods for the pressence of startch.
Dialogue: 0,0:00:04.70,0:00:09.98,Default,,0000,0000,0000,,The Experiment involves the use of chemicals. So wear safety goggles and gloves during the experiment.
Dialogue: 0,0:00:10.09,0:00:17.25,Default,,0000,0000,0000,,Today the chemical we will be using is Iodine solution. Which is Redish / Brown colour.
Dialogue: 0,0:00:17.25,0:00:20.84,Default,,0000,0000,0000,,And it will stain blue / black when startch is present.
Dialogue: 0,0:00:20.91,0:00:24.69,Default,,0000,0000,0000,,The foods we will be testing are Potatoe, Flour and Milk.
Dialogue: 0,0:00:24.74,0:00:33.07,Default,,0000,0000,0000,,The experiment simply involves adding a few drops of Iodine. To each food sample.
Dialogue: 0,0:00:33.09,0:00:38.75,Default,,0000,0000,0000,,When a few drops are added to the potatoe. It will stain Blue / Black in colour.
Dialogue: 0,0:00:38.75,0:00:44.09,Default,,0000,0000,0000,,Which indicates startch is present.
Dialogue: 0,0:00:44.09,0:00:53.08,Default,,0000,0000,0000,,When we add the chemical to flour. Again it will stain Blue / Black.
Dialogue: 0,0:00:53.08,0:00:59.08,Default,,0000,0000,0000,,And when we finally add the solution to the milk, there is no colour change...
Dialogue: 0,0:00:59.08,0:01:02.54,Default,,0000,0000,0000,,Indicating that there is no startch present in milk.
Dialogue: 0,0:01:02.54,0:01:06.13,Default,,0000,0000,0000,,That concludes Experiment OB3A...
Dialogue: 0,0:01:06.15,0:01:12.69,Default,,0000,0000,0000,,Experiment OB3B. Test a variety of foods for the pressence of reducing sugars.
Dialogue: 0,0:01:12.69,0:01:15.83,Default,,0000,0000,0000,,As with all experiments involving he use of chemicals.
Dialogue: 0,0:01:15.83,0:01:18.84,Default,,0000,0000,0000,,Safety glasses and gloves must be worn.
Dialogue: 0,0:01:18.84,0:01:26.20,Default,,0000,0000,0000,,3 Food samples we are going to use today are: Milk, Glucose Solution and Water. Which is acting as our control.
Dialogue: 0,0:01:26.20,0:01:36.84,Default,,0000,0000,0000,,The chemical involved is "Benedict's Solution." And it is added in equal volumes to each food sample.
Dialogue: 0,0:01:36.84,0:01:40.65,Default,,0000,0000,0000,,The food samples are then heated in a water bath.
Dialogue: 0,0:01:40.69,0:01:46.19,Default,,0000,0000,0000,,So, I'm going to add Benedict's Solution to each of the testubes...
Dialogue: 0,0:01:46.19,0:01:55.62,Default,,0000,0000,0000,,You add an equal amount of Benedict's to the amount of liquid in the testube.
Dialogue: 0,0:01:55.66,0:02:06.59,Default,,0000,0000,0000,,The testubes then need to be given a brief shake. To ensure that the liquids are fully mixed...
Dialogue: 0,0:02:12.22,0:02:17.93,Default,,0000,0000,0000,,Experiment - OB3C. To test a food sample for the presence of fat.
Dialogue: 0,0:02:18.02,0:02:21.15,Default,,0000,0000,0000,,Once again, we will need out Safety goggles and gloves.
Dialogue: 0,0:02:21.59,0:02:26.31,Default,,0000,0000,0000,,This experiment involves: Rubbing the food sample on Brown paper.
Dialogue: 0,0:02:26.40,0:02:32.17,Default,,0000,0000,0000,,I'm using butter, today. So, place a sample of butter onto the brown paper.
Dialogue: 0,0:02:32.17,0:02:42.18,Default,,0000,0000,0000,,And then, Rub the food sample on the brown paper. And take off the butter afterwards...
Dialogue: 0,0:02:42.18,0:02:49.18,Default,,0000,0000,0000,,And what we are looking for is, the presence of this spot. Which is known as a "Translucent" spot.
Dialogue: 0,0:02:49.78,0:02:55.30,Default,,0000,0000,0000,,It's similar to a grease spot. And it allows light to pass through it, but you can't actually see through
Dialogue: 0,0:02:55.30,0:03:03.30,Default,,0000,0000,0000,,the spot. And once you get that spot on the brown paper. That indicates the sample HAS fat in it.
Dialogue: 0,0:03:03.30,0:03:07.68,Default,,0000,0000,0000,,If you don't get that spot. Then the food sample does not contain fat...
Dialogue: 0,0:03:07.68,0:03:12.44,Default,,0000,0000,0000,,And that is the end of experiment OB3C...
Dialogue: 0,0:03:12.44,0:03:18.52,Default,,0000,0000,0000,,Experiment - OB3D. To test a variety of foods for the presence of Protein.
Dialogue: 0,0:03:18.52,0:03:23.67,Default,,0000,0000,0000,,Again, Safety goggles and gloves must be worn when handling chemicals in the lab.
Dialogue: 0,0:03:23.67,0:03:29.25,Default,,0000,0000,0000,,Today, we will use 2 food samples. Water and Milk. The chemicals involved in this test...
Dialogue: 0,0:03:29.25,0:03:36.59,Default,,0000,0000,0000,,Are "Sodium Hydroxide" and "Copper Sulfate."
Dialogue: 0,0:03:36.59,0:03:41.82,Default,,0000,0000,0000,,The first stage involves adding Sodium Hydroxide to the food samples. And you must add aprox. an equal
Dialogue: 0,0:03:41.82,0:03:53.91,Default,,0000,0000,0000,,volume of sodium hydroxide to the food sample being tested.
Dialogue: 0,0:03:53.91,0:04:07.66,Default,,0000,0000,0000,,The testubes must be briefly shaken to ensure the chemicals are mixed.
Dialogue: 0,0:04:07.66,0:04:12.65,Default,,0000,0000,0000,,And the last stage of this experiment involves adding a few drops of copper sulfate.
Dialogue: 0,0:04:12.65,0:04:17.76,Default,,0000,0000,0000,,As you can see copper sulfate is a Blue chemical. And if there is protein present in the sample, It will
Dialogue: 0,0:04:17.76,0:04:25.49,Default,,0000,0000,0000,,stain purple, when it meets the sample.
Dialogue: 0,0:04:25.49,0:04:28.41,Default,,0000,0000,0000,,As you can see, there is no colour change in the testube containing the water. Which indicates there
Dialogue: 0,0:04:28.41,0:04:35.32,Default,,0000,0000,0000,,is an Protein is absent in water. When added to the Milk...
Dialogue: 0,0:04:35.38,0:04:50.53,Default,,0000,0000,0000,,We should get a purple colour appearing at the top of the solution. This indicates protein is present
Dialogue: 0,0:04:50.54,0:04:57.08,Default,,0000,0000,0000,,in Milk. That is the end of experiment OB3D...
Dialogue: 0,0:04:57.08,0:05:05.17,Default,,0000,0000,0000,,Experiment - OB5. To investigate the conversion of chemical energy in food into heat energy.
Dialogue: 0,0:05:05.18,0:05:10.15,Default,,0000,0000,0000,,Safety goggles and gloves must be worn during this experiment.
Dialogue: 0,0:05:10.15,0:05:18.15,Default,,0000,0000,0000,,We are going to use a cream cracker as our food source. And we are going to ignite the cream cracker...
Dialogue: 0,0:05:18.15,0:05:22.32,Default,,0000,0000,0000,,And the chemical energy in the cream cracker, will be converted into heat energy. And will cause the
Dialogue: 0,0:05:22.32,0:05:25.57,Default,,0000,0000,0000,,temperature of the water to rise...
Dialogue: 0,0:05:25.57,0:05:52.78,Default,,0000,0000,0000,,Initally, the Temperature of the water is 23 oC. We will ignite the cream cracker using the bunsen burner.
Dialogue: 0,0:05:52.78,0:05:59.88,Default,,0000,0000,0000,,As the cream cracker burns, it emits chemical energy in the form of heat energy. This energy is being
Dialogue: 0,0:05:59.88,0:06:08.95,Default,,0000,0000,0000,,trapped by the water, and will cause the rise in temperature.
Dialogue: 0,0:06:08.95,0:06:32.11,Default,,0000,0000,0000,,We will allow the cream cracker to completely burn itself out...
Dialogue: 0,0:06:32.11,0:06:39.15,Default,,0000,0000,0000,,If we examine the temperature of the water in the testube, we will see it has risen from 23 oC to..
Dialogue: 0,0:06:39.15,0:06:50.65,Default,,0000,0000,0000,,50 oC. A rise of 27 oC. This shows the conversion of chemical energy in food into heat energy.
Dialogue: 0,0:06:50.68,0:06:56.60,Default,,0000,0000,0000,,Experiment - OB8. To investigate the action of the enzyme amylase on startch.
Dialogue: 0,0:06:56.60,0:07:01.76,Default,,0000,0000,0000,,Safety goggles and Gloves must be worn as chemicals are involved.
Dialogue: 0,0:07:01.78,0:07:07.50,Default,,0000,0000,0000,,Testube on the right contains startch and saliva. The one on the left contains startch and water.
Dialogue: 0,0:07:07.50,0:07:15.71,Default,,0000,0000,0000,,Saliva contains an enzyme called amylase. And that enzyme breaks down startch into a product called...
Dialogue: 0,0:07:15.71,0:07:31.53,Default,,0000,0000,0000,,Maltose. We will place the 2 testubes into a water bath at 37 oC for about 10 min.
Dialogue: 0,0:07:31.53,0:07:40.06,Default,,0000,0000,0000,,We now remove the 2 testubes from the water bath and test both testubes for the presence of startch...
Dialogue: 0,0:07:40.11,0:07:44.69,Default,,0000,0000,0000,,Using Iodine.
Dialogue: 0,0:07:44.69,0:07:53.70,Default,,0000,0000,0000,,We add a few drops of Iodine into each testube.
Dialogue: 0,0:07:53.70,0:08:02.41,Default,,0000,0000,0000,,The testube on the left, Iodine stays yellow / brown in colour. Indicating no startch present.
Dialogue: 0,0:08:02.41,0:08:09.16,Default,,0000,0000,0000,,The testube on the right stains blue / back. Indicating the presence of startch.
Dialogue: 0,0:08:09.16,0:08:17.90,Default,,0000,0000,0000,,From this experiment we can conclude that the amylase broke startch down into maltose.
Dialogue: 0,0:08:17.90,0:08:24.16,Default,,0000,0000,0000,,Where as the other testube, which was acting as a control. The iodine stained blue / back...
Dialogue: 0,0:08:24.18,9:59:59.99,Default,,0000,0000,0000,,indicating the presence of startch. That is the end of experiment OB8...