Paper 1 Biology - required practicles

Alternative transcript:

is the movement of water through a selectively permeable membrane from an area of high concentration of water to an area of lower concentration of water. Plant tissues, such as potato, can be used to investigate osmosis. 1 Draw a labelled diagram of an experiment to investigate the effect of a range of concentrations of sugar solutions on the mass of potato cylinders. ● ● Test tube rack 2 Describe how you could conduct the investigation of osmosis in potato tissue. ● Boiling tube ● Potato cylinder in solution 1 M 0.5M Water sugar sugar Gril • add one potato cylinder to a tube of 10 cm³ of 1 M sugar solution, one to a tube of 10 cm³ of 0.5 M sugar solution and a tube of 10 cm³ distilled water leave the potato cylinders in the boiling tubes overnight in the test tube rack cut three potato cylinders of the same diameter and length measure the length using a ruler determine the mass of each potato cylinder using scales re-measure the length and mass of each cylinder draw a graph of change in mass against concentration of sugar solution Biology 4.2 Organisation - RPA Enzymes The enzyme amylase controls the breakdown of starch in our digestive system. We are able to simulate digestion, using solutions of starch and amylase in test tubes, and find the optimum conditions required. State the equipment used and draw a labelled diagram of an experiment to investigate the effect of temperature on the enzyme amylase. ● ● spotting tiles pipettes • stop clock ● starch solution ● ● ● ● boiling tubes water bath ● amylase solution iodine solution 20 °C 40 °C 60 °C 80 °C 60 90 120 0 30 seconds seconds seconds seconds seconds Spotting tile 2 Describe how you could conduct the investigation of the effect of temperature on the enzyme amylase. Wells mix same volume of 1% starch solution 20°C with amylase solution 20°C after 30 seconds, add a drop of the starch and amylase mixture to a drop of iodine solution in one well of a spotting tile • repeat every 30 seconds until the iodine solution no longer changes colour repeat the experiment at 40 °C and at 60 °C and at 80 °C Biology 4.2 Organisation - RPA Food Tests We know that each dish is usually made up of one or more ingredients, called nutrients. Different food items contain different types of nutrients. State the equipment and chemicals used to tests different foods for carbohydrates, proteins and fat. • food to be tested ● ● ● ● . a pestle and mortar a stirring rod a filter funnel and filter paper test tubes Benedict's solution iodine solution Sudan III stain solution ♥ Biuret solution 2 Describe how you could use qualitative reagents to test for a range of carbohydrates, proteins and fat. grind up food samples and mix with water filter using a funnel with filter paper to obtain a clear solution use Benedict's solution in a hot water bath to test for sugar: if sugar is present, the solution will turn green, yellow or red after a few minutes use iodine solution to test for starch: if starch is present, a blue-black colour will appear use Sudan III stain solution to test for fat: if fat is present, a red-stained oil layer will separate out use Biuret solution to test for proteins: if proteins are present, the solution will turn pink or purple