Vitamin C and Scurvy PDF

Starter- True or False T or F 1 Iron is needed in the diet to make haemoglobin that carries carbon dioxide around the body. 2 Water is needed in the diet for metabolic (chemical)...

Starter- True or False T or F 1 Iron is needed in the diet to make haemoglobin that carries carbon dioxide around the body. 2 Water is needed in the diet for metabolic (chemical) reactions in cells 3 Fibre can help to prevent stomach cancer 4 To test for starch, you use iodine solution 5 To test for proteins, you use Benedict’s solution 6 To test for reducing sugars, you simply add Benedict’s solution and wait for a colour change. 7 The presence of proteins can be shown when Biuret solution turns from blue to brick red. 8 A positive result for starch is when iodine turns from orange to blue black. 9 A positive result for fats is when ethanol turns purple. 10 To test for reducing sugars you must heat up Benedict’s solution. 11 A little bit (trace) of reducing sugar will be shown if the Benedict’s solution turns dark orange/red. 12 Glucose is an example of a reducing sugar.  True or False Statement T or F 1 Iron is needed in the diet to make haemoglobin that carries carbon dioxide around the body. F 2 Water is needed in the diet for metabolic (chemical) reactions in cells T 3 Fibre can help to prevent stomach cancer F 4 To test for starch, you use iodine solution T 5 To test for proteins, you use Benedict’s solution F 6 To test for reducing sugars, you simply add Benedict’s solution and wait for a colour change. HEAT F 7 The presence of proteins can be shown when Biuret solution turns from blue to brick red. F 8 A positive result for starch is when iodine (solution) turns from orange to blue black. T 9 A positive result for fats is when ethanol turns purple. F 10 To test for reducing sugars you must heat up Benedict’s solution. T 11 A little bit (trace) of reducing sugar will be shown if the Benedict’s solution turns dark orange/red. F 12 Glucose is an example of a reducing sugar. T L6- Vitamin C and Scurvy Learning Objectives Testing for the presence of Vitamin C Developing practical skills in Biology Syllabus statements The 7 food groups Our bodies require 7 different food groups to stay healthy. We must make sure our diet contains the correct amount of each of the following: - Carbohydrates - Proteins - Fats - Vitamins - Minerals - Fibre - Water Food tests Food group Reagent Colour Sugar (carbohydrates) Benedicts Blue → yellow, green, orange, brick red Starch (Carbohydrates) Iodine Orange brown → Blue/black Protein Biurets Blue → Lilac Lipids Ethanol Clear→ Milky white emulsion Vitamin C Deficiency of Vitamin C Vitamin C (ascorbic acid) is needed to help heal wounds and maintain healthy connective tissue (which gives support to other tissues and organs). Oranges are a good source of vitamin C Good sources of vitamin C include: citrus fruits (such as oranges, lemons and limes) leafy green vegetables (such as sprouts and broccoli) Vitamin C deficiency leads to scurvy. The symptoms of scurvy include bleeding and swelling of the gums, loss of teeth, tiredness and muscle and joint pain. Testing for the presence of Vitamin C If Vitamin C is NOT present, DCPIP will stay dark blue DCPIP is dark blue to start If Vitamin C is present, DCPIP will turn colourless The fewer drops needed = the more Vitamin C is present The Method 1. Using a pipette, add drops of each fruit juice and shake quickly afterwards. 2. Continue until the DCPIP turns colourless. 3. Carry out the experiment TWICE for each fruit juice Independent variable Dependent variable Control variables Independent variable The type of fruit juice Dependent variable The amount of Vitamin C by counting the number of drops needed for DCPIP to turn colourless Control variables The volume of the drops The volume of DCPIP in the test tube The concentration (strength) of the DCPIP The amount of shaking The Results Fruit Juice Number of drops added before DCPIP turns colourless Attempt 1 Attempt 2 Mean A- Grapefruit juice B- Lime juice C- Orange juice D- Orange squash E- Lemon juice The Results Fruit Juice 1 2 Mean The Results Fruit Juice Number of drops added before DCPIP turns colourless Attempt 1 Attempt 2 Mean Orange juice 21 25 23 Lemon juice 43 49 46 Carrot juice 82 96 89 Grapefruit juice 40 44 42 Orange squash 76 84 80 Task 1- Plot graphs Pit stop In this investigation, what is the: Independent variable Control variable Dependent variable How did we ensure that the results are reliable Task 2 Use this checklist when drawing your graph Review the keywords so far using the quizlet. Some of the statements are ‘challenge’ statements.