biol+3+faq+(nsfaq)+aos2+part2



If you have any any questions or are uncertain about anything to do with the course, then this is the place to get help. It will be up to you (as a class) then to answer the issues raised. You can keep your input anonymous or include your initials, it's up to you.


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In the toolbar you will notice an 'A' with three colours under it. To change the colour of your text, you need to highlight the text first, then click on the 'A' button. Now click on rectangle next to 'colour' and type in the following: For a question type in **#750a56** to change to **dark magenta** For an answer type in **#17066a** to change to dark purple

Or you can use what ever colour you wish by click on the outside ring of colours and then on the inside square. biol 3 faq (nsfaq) aos2 part1
 * In case you want to jump to the other aos2 page the link is below. **


 * <span style="COLOR: rgb(117,10,86)">Q. I was just wondering if we will be getting any more notes before the exam? **

//<span style="COLOR: rgb(23,6,106)">A. Nope, that's it. I have now given you the notes for the whole course. //


 * <span style="COLOR: rgb(117,10,86)">Q. Are we expected to know about enzyms and diseases (textbook-page 33-34) **

//<span style="COLOR: rgb(23,6,106)">A. Absolutely, this was a part of the enzyme SAC. You do need to know the specifics of any disease but you should be able to understand how an abnormal enzyme (due to mutation) can result in a particular reaction not occurring as effeciently and thus affect some biochemical pathway which can then lead to a disease. VM // <span style="COLOR: rgb(117,10,86)">**Q. So we are not expected to know galactosaemia, lactose intolerance and phenylketonuria?** <span style="COLOR: rgb(23,6,106)"> //A. No you don't need to know the specific details of these and if you came across them in an exam question, I would think you would have no probelms identifying them as enzyme-based diseases, even though you wouldn't be expected to remember this. You should always be provided with information if a question is being specific about a disease, negative feedback system, signal transduction etc. VM//


 * <span style="COLOR: rgb(117,10,86)">Q. Hey voy.. can you please put up the answers to the summary table on the pathogenic agents?? thanks **

//<span style="COLOR: rgb(23,6,106)">A. Will do. You can go to the classroom stuff page or directly to the pathogen summary table page. VM //

but if a question asked how many carbon sugars does photosynthesis produce.. do we say 2x3-carbon compounds?? **
 * <span style="COLOR: rgb(117,10,86)">Q. how much detail do we need to no about C3-plants and C4-plants and rubisco??.. (just that C4-plants dont have their stomata open as long, so reducing their water loss, therefore are more efficient in hot and dry environments)??

//<span style="COLOR: rgb(23,6,106)">A. Good question. Yes, photosynthesis produces 2x3C-compounds which are converted to glucose. In terms of the inputs and outputs (which is what you need to know), glucose is the answer they would look for. But if you are unsure about a question, you could always write "2x3C compounds that are converted to 6C-glucose". VM // //<span style="COLOR: rgb(23,6,106)">A. In relation to C3 and C4, you should know that C4 plants have a more efficeint pathway that utilises CO2 better and therefore they don't have to keep stomata open for as long which is beneficial in a hot/dry environment. Its probably worthwhile knowing that rubisco is an enzyme involved in "fixing" CO2 during photosynthesis. VM //

<span style="COLOR: rgb(23,6,106)">**<span style="COLOR: rgb(117,10,86)">Q. Is there a difference between when a question is asking "is there a control present in the experiment" or "what factors have been controlled in this experiment"? **

//<span style="COLOR: rgb(23,6,106)">A. Yep absolutely! This is a very important question. You must all be clear on this, as understanding of experimental procedure will be somewhere on the exam. A "control" in an experiment is the set up that all other set ups are compared to (ie the one that is the "normal" situation"). Factors that are controlled in an experiment are all the variables that are being kept constant between the set ups because we don't want them to influence the results. I think it would be great if you could provide an example of your own (below) to show your understanding of this. VM //<span style="COLOR: rgb(23,6,106); BACKGROUND-COLOR: rgb(255,255,255)"> <span style="COLOR: rgb(23,6,106)"><span style="BACKGROUND-COLOR: rgb(23,6,106)">  <span style="COLOR: rgb(23,6,106)">//A. So let's say in the liver-catalase experiment, the control would be the test tube with the liver and distilled water (that is, not affected by the variable H2O2), whereas factors that are controlled would be the the size of the liver in each test tube, as well as the amount of time that passes up till which the oxygen bubbles can be recorded. AP// <span style="COLOR: rgb(19,22,241)">Yes, if the variable you are testing is H2O2 conentration, then a test tube with only liver and water would be the control set up. And you are spot on with the other factors being controlled. You will need to be able to apply this in understanding in any experimental-based question (which there are pretty much an infintie number of!) VM

<span style="COLOR: rgb(117,10,86)">**Q. One of the trial exams asks about CAM photosynthesis. Would you say we'd need to know about CAM plants as well?**

//<span style="COLOR: rgb(23,6,106)">A. Adpatations that organisms possess to be able to respond to changes in the environment are part of the course. In the current course you only really need to know about PHYSIOLOGICAL adaptations. CAM (crassulacean acid metabolism) photosynthesis is an example that you should be familiar with but only to the extent I have mentioned in the course notes. It is different to C3 and C4 plants in that CO2 is taken up during night (so no water loss) and stored in another form within leaf. Then during day (when sunlight is available and 1st stage can occur) the stomata need not open as the stored carbon is converted back to CO2 to be used for 2nd stage. VM //

<span style="COLOR: rgb(19,22,241)">One other thing these sorts of questions which relate to a trial exam I would like posted on the trial exam analysis page please. I have copied the above one there. VM

** //<span style="COLOR: rgb(23,6,106)">A. An excellent question. First you must be careful in your wording. "communication across a synaptic cleft is NOT a signal transduction pathway" BUT yes, it results in a signal transduction pathway. This is because the neurotransmitter binding to membrane receptor (signal) is then converted into a cellular repsonse (action potential). The series of events leading up to the generation of the action potential would be referrred to as a signal transduction pathway. VM //
 * <span style="COLOR: rgb(117,10,86)">Q. So, what's an antigen again? Just kidding! What I really want to ask about is what signal transduction pathways refer to...I get the idea, but sometimes I'm confused. I know that steroid and protein hormones initiate signal transduction pathways, but does the communication across a synaptic cleft also get referred to as another signal transduction pathway?

Q. hey voj.. do we have period zero tomorrow? <span style="COLOR: rgb(19,22,241)">**There will be no period zero on Yom Ha'Atzmaut. I will put it on the homepage but may be if you can let others know. VM**


 * <span style="COLOR: rgb(117,10,86)">Q. In regards to the first level of non-specific defence, would mucus-secreting membranes be classed as a physical barrier of defence and mucus itself as a chemical barrier? Wasn't really sure about the distinction between the two. **

<span style="COLOR: rgb(23,6,106)">//A. OK, I suppose you could look at it like this. The presence of mucus could act as a physical barrier but it can also be chemical if it contains substances that affect possible pathogens in some way. VM//

<span style="COLOR: rgb(117,10,86)">**Q. how specific do we need to know neurotransmitters? you gave us examples in the course notes of common neurotransmitters - do we need to know these? or just understand generally what they are/what they do etc..????**

//<span style="FONT-SIZE: 110%; COLOR: rgb(23,6,106); BACKGROUND-COLOR: rgb(151,17,17)"><span style="COLOR: rgb(255,240,240)"><span style="COLOR: #17066a; FONT-FAMILY: Arial, Helvetica, sans-serif; BACKGROUND-COLOR: #ffffff">A. You certainly need to know in general their role in detecting and responding. Also, I think you should always be able to provide an example. So, I suggest that you are familiar with one or two neurotransmitters and their roles. For example acetylcholine is the main neurotansmitter so I would know that one. VM  //

<span style="COLOR: rgb(255,240,240)"><span style="COLOR: rgb(249,246,241)"> <span style="FONT-FAMILY: 'Times New Roman', Times, serif"> **<span style="COLOR: #750a56; FONT-FAMILY: Arial, Helvetica, sans-serif"><span style="FONT-FAMILY: Verdana, Geneva, sans-serif"><span style="FONT-FAMILY: 'Palatino Linotype', 'Book Antiqua', Palatino, serif"><span style="FONT-FAMILY: 'Courier New', Courier, monospace"><span style="FONT-FAMILY: Georgia, serif"><span style="FONT-FAMILY: Tahoma, Geneva, sans-serif"><span style="FONT-FAMILY: 'Trebuchet MS', Helvetica, sans-serif">Q. in the cell mediated response, you know how the T helper cell proliferates onces it binds with the macrophage, it says in the cause notes the T helper cell stimulates the production of T cytotoxins cells and B cells --> so do the T helper cells deferentiate into cytotocins; how are cytotoxins made and where do the B cells come from;<span style="FONT-FAMILY: Tahoma, Geneva, sans-serif">       ** **<span style="COLOR: #750a56; FONT-FAMILY: Arial, Helvetica, sans-serif"><span style="FONT-FAMILY: Verdana, Geneva, sans-serif"><span style="FONT-FAMILY: 'Palatino Linotype', 'Book Antiqua', Palatino, serif"><span style="FONT-FAMILY: 'Courier New', Courier, monospace"><span style="FONT-FAMILY: Georgia, serif"><span style="FONT-FAMILY: Impact, Charcoal, sans-serif"><span style="FONT-FAMILY: Tahoma, Geneva, sans-serif"><span style="FONT-FAMILY: 'Trebuchet MS', Helvetica, sans-serif">are they just attracted to that site and then proleferate and so on. Im a bit confused :( Sar       **<span style="FONT-FAMILY: Tahoma, Geneva, sans-serif"><span style="FONT-FAMILY: Verdana, Geneva, sans-serif"> // A. OK, first you need to be clear on the terminology. T-cells come in a variety of types. Helper T-cells and Cytotoxic (not cytotoxins) T-cells are two types that we already have floating around in our lymphatic tissue. Now, Helper T-cells do not become Cytotoxic T cells! Helper T-cells will clone themselves so that there are more of them but they also send out chemical signals to Cytoxic T-cells (that will have the same type of receptor on its surface as the Helper T-cell). They will also send out signals to B cells (that have a matching receptor on its surface) and this stimulates that particular B cell to reproduce and differentiate into plasma B cells and memory B cells. VM //


 * Q. What's the difference between surface markers and MHC markers and self-antigens? All the different names are just sort of confusing. **

// A. First of all surface markers is just a general term used to refer to the molecular characterstic of a plasma membrane, this will, off course, include the protein bits that we refer to as self-antigens and non-self antigens. MHC markers or MHC proteins refers to those markers displayed on our own cells as a result of the group of genes called the MHC. Now, these MHC markers could be self-antigens or non-self antigens depending on the situation. I can understand the confusion, there are just so many variations to the terms. Fire away with another query if you need more clarification. VM //


 * Q. The R group in a protein structure, can this be any element (C,H,O,N,S) or does it have to be a sulphur element? **

// A. OK, the R-group will usually contain some combination of C, O, N and H, although not all 20 will necessarily have N and/or oxygen. It varies! BUT only 2 of the 20 amino acids actually have S in their R-group. Do a google search (images) for amino acids and you will be able to see how the R-group varies. Important- you do not need to know the R-group structures of each amino acid, just that they are the variable region between the different amino acids and that a couple also contain the element S. VM //


 * Q. Is it the proteins R group that bind together to from the tertiary stage? **

// A. Yes, pretty much. The tertiary structure is due to a number of different interactions between the R-groups of the amino acids in the polypeptide. So it includes, H-bonding but also it includes the distinctive S-S bonding (sulphur bridges) that will occur between those two amino acids that have S in the R-group. VM //


 * Q. what is the role of glycoproteins, it is cell communication like glycolipids (self marker)? :) **

// A. Yep, they are part of the cell recognition process, ie they act as self markers. As in the MHC molecules on the plasma membranes of white blood cells. Also, antibodies themselves are glycoproteins. VM //

**Q. im just doing a question on the movement of molecules and its asked me why do root cells expell energy when taking up certain substances from the soil, it it because they take up certain minerals and ions (even though they have a larger concentration of them inside the cell) against their concentrated gradient, dont know what they want me to say?**

// A. What you have said sounds pretty good to me. if energy is being used (ie active transport) to move substances it will be against their concentration gradient. This is definitely the case when root hair cells take up minerals and ions from the soil (lower concentration in the soil). Remember by doing this it results in a high solute concentration in the root hair cell (low free water) thus it allows plants to take up water by osmosis.VM //


 * Q. can B cells be stimulated two ways. 1 they 'bump' into them in lymph whencauses them to differentiate and 2 they are stimulated by T helper cells (via cytokine)? :) **

// A. Ok, this is a bit of a confusing one. Bcells can come across an antigen that they match with but it seems this is not necessarily enough for them to be stimulated to divide and differentiate into plasma and memory Bcell. So, the role of the Thelper cell (that has come into contact with the same type of antigen) is crucial in stimulating that particular Bcell (via release of cytokine, ie interleukin-2) to actually clone itself and differentiate. VM //


 * Q. hi Voj i was just writting notes for the blood type topic and on page 42 of the course notes the table 12 says genotype, do we need to understand this. I was going through it with my sister and she was explaining alleles, but im not sure if we need to know this? :) thanx **

// A. no you do not need to know about genotypes, this is unit 4. VM //


 * Q. is chlorophyll found on the thylakoid membrane sac? **

// A. yep. VM //


 * Q. When will the uber cool amazing really really special good looking Dani Robinson come and talk to the year 12s? Anonymous **

// A. hmm do we need help from oustide the class. why not! I will email her for you. VM //


 * Q. I came across the term exocrine gland, what is the difference between that and endocrine glands? Are they the same thing? **

// A1. No they are not. Exocrine glands release/secrete substances and contain ducts. eg sweat glands are exocrine glands. the difference is that exocrine glands contain ducts/tubes and generally do not release hormones. therefore they are not relevant to the endocrine system and the role of hormones, so do not worry about them. VM //


 * Q2. I also found a text that stated that hormones are USUALLY produced in endocrine glands, but can be produced in neurons..is this correct? Confused because we have always talked about hormones being released from endocrine glands. **

// A2. you need to be familiar with neurohormones as a type of signalling molecule. these are released by neurons in the brain tissue (hypothalamus). these neurons are also referred to as neurosecretory cells. the neurohormones travel to nearby target cells such as in the pituitary. it is one way that the nervous system links with the endocrine system. VM //