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tags ยป Biology (2266)

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Hi, I'm currently studying the AQA Human Biology syllabus and was asked to write up my results for the above experiment. This is the instructions for what we had to do: 1. Use a cork borer to cut out a cylinder of beetroot, then use a ruler and scalpel to cut the cylinder into a series of discs with uniform thickness (5mm is probably best) you will need at least 24 discs. 2. Rinse the beetroot discs by placing water in a Petri dish. This gets rid of any pigment which has spilled out of the cut cells. 3. Measure a fixed volume of distilled water (I suggest 10cm^3) into each of 6 test tubes. Add 2 beetroot discs to each tube. 4. Leave one at room temperature and place the other tubes in baths at other temperatures (use a good range). Note the thermometer reading in each bath do not assume that the temperature is that shown on the thermostat dial or the label. 5. Leave the tubes at your chosen temperatures for about 40 minutes (make sure the time is the same for each tube). This ensures that the contents of the tube have reached the temperature of the bath and been held at that temperature long enough to affect the cell membranes. 6. Remove all tubes at the end of the time alloted and separate the liquid from the beetroot discs. This can probably be done by decanting the liquid into another tube, leaving the beetroot disc behind. 7. Ensure that the liquid in each tube is thoroughly mixed, then use a colormeter to measure the absorbance of green light for each tube relative to the absorbance of a distilled water blank. Now I have to analyse the results and describe the trend or pattern and explain what the results say about the effect of heat on cell membranes and explain how it occured and which molecules were effected and how. I also have to identify which results I think is wrong or unreliable and consider how the errors may have occured and state whether there was anything I could have done to improve accuracy/reliability. Please could you tell me how to go about this as I do not have any idea and this counts toward my final grade. I don't really have a clue how to do it. Thanx!
can you give me a brief introduction to osmosis in potatoes for a piece of coursework. is it any different to other osmosis?
I have been asked to investigate why the colour leaks out of cooked beetroot! please give me some information i could include in write up! thanks!

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According to the AQA syllabus, to gain the E.6b mark on my evaluation i need to, "describe, in detail, further work to provide additional relevant evidence". What further investigation should i talk about to gain this mark and could you please explain how this is relevant . The investigation you suggest must be linked to Osmosis. THANKS FOR READING THIS! :)
My coursework exp was to cut pieces of beetroot of the same size, wash them under running water -to remove pigment released from the cells damaged by cutting and sizing then place the pieces into test tubes of water at pre heated temps of 20, 30,40, 50, 55, 60 and 70 degrees. the betroot were added to these water temps for 15 mins,the now, red coloured liquid drained and kept to be analysed using a colorimeter. This was to determine at which temp the most pigment was released, as expected the hottest temps were coloured the deepest red colour. I understand that this is due to the damage and denaturing of the cell membranes at high temps allowing the pigment to be released from the vacuole, but in my write up i want to comment on the reason for there being any pigment release at the lower temps, why is there any pigment released from what should be intact cell membranes at temps upto 40 degrees, is it to do with diffusion? however i thought the reason the pigment was held in by the membranes is because its molecules are too large to pass through the membrane? so how does this pigment leak out at the lower temps if all pigment from broken cells was washed off before heating? Are there any key points you advise i mention in the write up? Thanks in advance, Alison
I did an investigation on the absorbtion of pigment from a beetroot in distilled water, and i set up 5 diffrernt tepertauere water baths for the beetroot to sit in.( 0, 20, 30, 40 and 55 degrees c ) And to explain what is happeningm i know it has something to do with the plasma membrane, and i think it has something to do with protiens, but i'm not sure- can you help?
i have just received my c/w for OSMOSIS with potatoes. i haven't got a clue of what to do, since i have started new to Double Science therefore i need help on this topic. How can i find information on the net? what websites? have you got any information that you can provide me with? thank you, Abdullah
I am doin an experiment at school with osmosis and we have to use a visking tube. The visking tubing is placed in a beaker and tested for starch and glucose to see if osmosis had taken place. But i Don't really understand. Please help.
"experiment to investigate osmosis in potato tissue using water and different sucrose solution" how will osmosis be affected using different sucrose solution.
I need to research information on osmosis, plasmolysis, incipient plasmolysis and solute potential. I would like, if possible, as much information on this as possible so that I can construct my plan. I need to find out what red onions are made of and if this affects the rate of osmosis compared to potato cells. I also need to find out about incipient plasmolysis in red onion cells and the effect of soute potential. Is there anything else that I should include in the plan of my coursework to do with osmosis and plasmolysis in red onion cells? How could I conduct the experiment?
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