biol+3+membrane+SAC

The practical component will be done on Tuesday 17th February. The written report will be finished during class on Friday 20th February.

**SAC criteria**

[|biol 3 membrane sac intro 2009.doc]


 * How to prepare **


 * Concepts you need to know and understand (no pun intended!)**
 * membrane structure
 * passive movment of substances through membrane
 * active transport of substances through membrane
 * bulk transport (endocytosis and exocytosis)
 * relevant terminology to all the above, including the types of biomolecules
 * be able to explain why substances move through particular parts of the membrane and not others, be able to use a specific example


 * How to prepare for the SAC**
 * do a "compare and contrast" and a "terminology analysis", you can download templates from the activities page
 * go over the relevant questions on the quizzes and course notes
 * do relevant questions from the chapter review in the textbook
 * do relevant puzzles on membranes from the puzzle booklet
 * read the relevant sections from the course notes and the textbook
 * come up with questions and post them below to clarify concepts as well as the scientific method

**Post any specific questions below**

Q. In the criterion, what are the questions you are referring to? ('Q8, 9, 14....') Are they from the textbook chapter review, or are they the numbered report questions?? //A. The numbers refer to the actual questions on the written report. so you can see there will be 15 of them. You will be able to see the first 6 questions on Monday. The remainder you will see in Friday's lesson. VM//

Q. In the hypothesis, are we allowed to use 'I' as in "I predict that...". If not, how would you word a hypothesis in third person? Hendrix //A. Ok Jimi, first things first. If I can aspire to and achieve to be half as good as you, then i will be able to call myself an exceptional guitarist. Conversely, if you can aspire to and achieve to know and understand biology half as well as me then you are on your way to gettting a 50. Right, I'll define a hypothesis for you. It is a statement that proposes an explanation to some phenomenom. It must be testable, in other words an experiment is used to either support or disprove the statement. as such, it should be written in a certain way. Never use the word "I" and it should not be written as a prediction. A hypothesis should contain an independent and dependent variable as this allows it to be testable. eg. "If the temperature of the environment is increased then the rate of the reaction will also be increased." The independent variable is the temperature (that is the thing we will change) and the dependent variable is the reaction rate as we are suggesting that it depends on the temperature. Hopefully, you can see that if we conduct an experiment to test this it will either support (never prove) or disprove it. We also may get results that suggest a need to modify our understanding of temperature and reaction rate. So think about the experiment your group is doing (not the class experiment) and suggest a possible statement to explain what might happen. Let me know if you need more explanation of this. VM //

Q. As far as my understamding goes, this is what i extracted from your answer: The hypothesis is to be written as a statement not a prediction and in the statement i need to identify the independant variable and explain how i think it will affect the dependant variable. My experiment will then support or disprove this statement. An example could be "As the amount of solute concentration increases (in the beaker), the amount of water leaving a cell will increase and thus reduce the mass of the cell." //A. How good are you or how good am I at being such a fantastic teacher that you understood so well what I was trying to explain. Off course, I'm being sarcastic here, it must be the long day, I seem to be in a strange mood. Anyway, your reasoning is spot on, as is the hypothesis. Although I will add, include as much detail that is specific to the experiment you are doing. VM //

Q. For the graph in Question 5, are we graphing just our group results or the class results. //A. Without being too harsh here, if you read the first line of question 5 the answer is there. "for each of the four set ups" VM //

Q. a few things.. 1) the 40 degree group, had no negative mass changes.. is this due to incorrect procedure and faults? could this be an "optimum" temperature for the celery? 2) is 60 degrees "too hot" for the celery? LOVE: AK, SS, & MW. //A. you have noticed some interesting results that don't seem to fit in within the theory that you may have. So, coming up with possible explanations is what is needed. You have suggested some above. You need to explore wiidely using your understanding of membranes and factors that affect them. I am not going to tell you any, that is for you to do. The key is that you can logically support your idea with some theory. VM //

Q.VOJ, is the SAC based primarily on our own groups results or the class results? will we need to refer to the table we drew up in the SAC? loooooooooooooooooove, SS. //A. in relation to anaylsing and interpreting the results, questions will predominantly be about your own group's results. However, I have asked you to record the class results for different temperatures. So you can expect one or two questions to do with analysing and interpeting these results. VM //

Q. For question 6 at the end it states "explain your choices." Does this mean we are meant to explain why the results ended up this way or just why we choose that specific solution to identify? // A. Fair enough. The latter one. Explain why you chose that specific solution to identify. VM //

Q. still slightly confused about Q.6. (this is more of a confirmation...correct me if im wrong)....im assuming you mean "based on the __first__ table of results for Q.4" (ie. not the class results), because otherwise, the sucrose solutions we choose to identify differ (in gain or loss of mass) in the different tested temperatures, (eg. the same sucrose solution could increase OR decrease in mass, depending on its level of temperature)....true? does that make sense?!... // A. OK fair enough, I can see that there might be confusion with which table is relevant to question 6. The question refers to you own table on the observations you made describing the celery pieces. You do not refer to the class results or any other tables. So your first assumption is correct. VM //

Q. (Referring to the above question) One of the groups (40 degrees) did not have a 'loss in mass' (due to what I only expect was inaccurate testing/results). Based on all the class results, the greater the concentration, the greater the amount of mass lost. Basically what i'm trying to ask is; Even though our results were innacurate and somehow stuffed up, should we still use the results or simply state what our results were, why we found them, but the general gist should be what USUALLY would happen? // A. First of all, you must answer the question that is being asked. Therefore you must know the difference between making a statment about your results. Explaining what your results say. Comparing your results to theory (or what you expected) and making a conclusion based on your results. Don't put you own spin on the question and alter its meaning just so that you can write what you want to write. No matter what results you got, you will always be able to answer the question. VM //

**Class results**

** For the 40 degree group: The 10% Concentration answer should be +8.84 //__not__// +8.44. This is because 1.2/13.57 X 100 is 8.84. Sorry for the misunderstanding. maths rocks. //Thx for that I will not put up a new image, as I assume people can make the amendment to their own tables and the above explanation is very clear. One last thing, I only ever want to see BIOL ROCKS! VM// Q. If i happened to have already written in for question 6 examples taken from the class results of when there was a gain or loss in mass, would you want me to change me response. Also, if you wanted that response to be based on our observations and touching of the celery, isn't that objective? Shouldn't we be using the results that are black and white? (J. Page) // A. The question as I have written above does not relate to class results, you must write about your observational results from the table in question 4. It does say in BOLD **your table of results**. I think you mean subjective but I am getting your to anaylse results from two different perspectives, that is all. Science isn't always black and white, in fact far from it. VM //
 * Please make sure you check that these results are correct for your group. Also, double check your calculations as soon as you can and if you find an error, let everyone know by posting the message below this.

Q. the questions that we will be responding to tomorrow, are based only on our group experiments/results? or also on the class results? eg. the conclusions we make. // A. I have answered this question above. VM //