Cells must move materials through membranes and throughout cytoplasm in order to maintain homoeostasis. The movement is regulated because cellular membranes‚ including the plasma and organelle membranes‚ are selectively permeable[1]. The purpose of an automatic flow of molecules is to create equilibrium on each side of the membrane. In order for molecules to pass through the membranes‚ there must be pores. The size of the pore determines what molecules can cross. Due to the size and polarity‚ only
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Examining Diffusion and Osmosis Introduction: Purpose: 1. To simulate and observe the diffusion of solutes and the osmosis of water through a semipermeable membrane through color change and sugar tests. 2. To speculate osmosis occurring in dialysis bags and potato cores by comparing percentage change in masses. Background information: Molecules are always in random‚ constant movement due to their kinetic energy. This causes the molecules of a cell to move around and bump into each other
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2. Preparation Of 1 M Na2CO3 Molecular mass of Na2CO3 = 106g Mass of salt in 100 ml of 1M solution = 10.6g Weighing of salt using electrical balance * Mass of Na2CO3 + beaker = 78.64g * Mass of beaker = 68.04g * Mass of Na2CO3 = 10.6g 1. 10.6g of Na2CO3 was weighed in a dry beaker. Small amount of distilled water was added and the salt was dissolved. 2. The contents of the beaker were transferred to
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rates You’ll be studying various aspects of kinetics of three reactions. A. Reaction between lead nitrate (PbNO3) and potassium chromate (K2CrO4) solutions B. Reaction between potassium permanganate (KMnO4) and oxalate ion (C2O42-) C. Iodine clock reaction A. REACTION BETWEEN LEAD NITRATE AND POTASSIUM CHROMATE SOLUTIONS Lead nitrate reacts with potassium chromate to form yellow lead chromate precipitate and aqueous potassium nitrate. The formation of a yellow precipitate indicates
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The water was tested for each initial chemical test because it served as the controlled variable. Since water is pure oxygen and hydrogen unlike Glucose and Starch‚ one variable may be observed. 2. Biuret reagent will turn your skin brownish-purple. Explain why this occurs. Biuret reagent will turn your skin a brownish-purple because Iodine detects protein in a substance by changing the color to a brown or purple shade‚ and since your skin contains protein it will also change color. 3. When greasy
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and iodide‚ as described above. The reaction produces iodine‚ the change in concentration of which can be measured over a given length of time. However‚ any colour change in this reaction is very gradual‚ and so although it is possible to measure this colour change‚ it is subject to a high degree of inaccuracy. Therefore we also add 2 other chemicals to the reaction – sodium thiosulphate (Na2S2O3) and starch. The S2O32- ion reacts with any iodine produced in the first reaction according to the following
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Saliva Lab Since the amylase enzyme is present in saliva‚ starch digestion begins in the mouth. Salivary amylase changes the polysaccharide starch into many disaccharide molecules of maltase (a simple sugar) which are further broken down into glucose units by maltase enzyme in the As stated above‚ saliva contains the amylase enzyme which begins the breakdown of starches. The efficiency of starch digestion by amylase can be measured by how much simple sugar it produces under
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KI‚ starch‚ HCl‚ NaHSO3‚ Na2S2O3 3. Pipette for stirring chemicals in reaction 4. Pencil and paper 5. Safety goggles* Procedure: 1. Make a chart to record collected data from the experiment 2. Gather all necessary chemicals and other materials 3. Mix one drop of KI with one drop of NaOCl and observe if a reaction takes place 4. If no reaction is visible add one drop of starch to the mixture and once again observe if a reaction occurs. If a reaction occurs still add one drop of starch to the
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Enzymatic Activity of Salivary Amylase Abstract: Salivary amylase is an enzyme that can digest starch molecules and break them down to sugar molecules. In this experiment‚ the enzymatic activity and specificity of salivary amylase was examined depending on the changes in pH and temperature. In the first part of the experiment‚ the effect of temperature was determined‚ using constant temperature bath (4‚ room temp‚ 37‚ 50‚ 60‚ and 70°C). Having the room temp and 50°C as the highest and 37°C as infinite
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of any of these essential ingredients leads to many diseases. For example‚ calcium and phosphorus are required for the formation of bones and teeth deficiency of these causes the decay of teeth and bones. Deficiency of iron causes anemia. Lack of iodine causes goiter. So it is necessary that the food we eat be selected carefully. Besides wheat‚ rice and milk‚ fruits and vegetables form an important part of balanced diet. They contain minerals‚ carbohydrates and vitamins. We are advised by doctors
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