essence_of_cool Posted March 18, 2009 Share Posted March 18, 2009 Hi people... I had a SAC (student assessed coursework) yesterday and i have a test on it next week, and i was wondering if i could get some advice. Firstly if anyone has done anything similar to this before (below) heads up would be great (although admitedly, cheating... but anyway) The prac was this: We reacted equal amounts of hyddrogen peroxide into mixtures of detergent, and liver, where each of the three test tube used had fresh dice liveer smaples, boiled samples and crushed samples (with sand) respectively. The reesults were that the first andd last eruted in bubbles and the boild sample did nothig. My knowledge so far of this, is that with the fresh liver, moderate amounts of catalase were around, and with the crushed one (crushed with sand) the ceells were brroken open releasing the (intracellular) catalase into its surroundings, provivding much more to react with. The boiled sample had all its enzymes denatured so no reaction present. The bubbles were the reult of large amounts of O2 being formed as a I still however dont understand the role of the detergent, as reading online i find that the reaction, bubbling, would've occured regardless of detergent present. y friend claimed that the edetergent killed cells releasing more catalase,, giving moreevident relsuts, but i doubt this. The kind of questionss my assesers are going to be asking are the sort where they ask me to draw daigrams and make graphs. Note that im not doing this to cheat, im doing it because its a good way to do research, to learn from thoise more experienced than me, and also, my teacher suggested it too... Any help would be appreciated. thanks Link to comment Share on other sites More sharing options...
gonelli Posted March 18, 2009 Share Posted March 18, 2009 Ahhh... VCE. It wasn't so long ago that I did that experiment. By the way, I thought SAC stood for "School Assessed Coursework"? Anyway, you look to be pretty much on the right track. However, with the ground liver sample there may be another reason for increased reaction (it is a concept that the course wants you to link back to, so look through your notes). As for the detergent... when you blow bubbles into a glass of water, how long do they last for? Think about that. Link to comment Share on other sites More sharing options...
essence_of_cool Posted March 19, 2009 Author Share Posted March 19, 2009 In response to gonelli... cool thanks... but i heard from a tutor that the detergent emulsyfies the cell membranes, breaking open the cells releasing catalase... Also i heard that the grounding with sand breaks open the cells... The only other hing i can think of with regards to the crshing is that it increases surface area to volume ratio, but ultimately,i dont see how that would play a role as there is no transfer of material across a membrane relevant.., only release or unreleased catalase (catalas is protein = too big for diffussion, hence no trnasfer) and catalase would be released determined by whether the cells got crushed or not... anything here ring true.. replies appreicated... Link to comment Share on other sites More sharing options...
CharonY Posted March 19, 2009 Share Posted March 19, 2009 I am not sure where the problem is. Using sand is necessary to create enough friction force to effectively open the cells. And the detergent help (membranes essentially consist of a lipid double layer). Link to comment Share on other sites More sharing options...
essence_of_cool Posted March 20, 2009 Author Share Posted March 20, 2009 Hewy you know what... thanks guys... i think i have enough info for this small SAC. Thanks for the advice, it helped. thaks and cya Link to comment Share on other sites More sharing options...
Mr Rayon Posted March 22, 2009 Share Posted March 22, 2009 In response to gonelli...cool thanks... but i heard from a tutor that the detergent emulsyfies the cell membranes, breaking open the cells releasing catalase... Also i heard that the grounding with sand breaks open the cells... The only other hing i can think of with regards to the crshing is that it increases surface area to volume ratio, but ultimately,i dont see how that would play a role as there is no transfer of material across a membrane relevant.., only release or unreleased catalase (catalas is protein = too big for diffussion, hence no trnasfer) and catalase would be released determined by whether the cells got crushed or not... anything here ring true.. replies appreicated... Wow...I didn't mention the role of the detergent at all in my SAC. You are very lucky to have so much time to figure it out. As for the above, I'm not quite sure on what happened in that experiment. My teacher has not explained what sort of deductions we should have formulated based on observation. If you'd looked at one of my previous posts you will see that I wasn't sure exactly what happened to great detail also(thus the need for clarification). Incidentally, I know our practical was the same but for your written SAC, will you be doing a practical report? Merged post follows: Consecutive posts merged I still however dont understand the role of the detergent, as reading online i find that the reaction, bubbling, would've occured regardless of detergent present. y friend claimed that the edetergent killed cells releasing more catalase,, giving moreevident relsuts, but i doubt this. Hmmm...well interestingly my friend told me that the detergent allowed to reaction to start. But I don't believe him as I poured the detergent after the reaction began. Note that im not doing this to cheat, im doing it because its a good way to do research, to learn from thoise more experienced than me, and also, my teacher suggested it too... Your teacher eh? Well now I feel heaps better about asking help...lol Link to comment Share on other sites More sharing options...
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