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Edexcel A2 Biology Unit 5 (6BIO5) - 22/06/2011- OFFICIAL THREAD !

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1 question for the article. How would the "long QT syndrome" be fatal??
Reply 2141
Guys is the whole paper synoptic or just the questions on the article?
Original post by sadbuttrue92
1 question for the article. How would the "long QT syndrome" be fatal??


Long QT syndrome is where the timing between the QRS complex and the T wave is so long that it delays repolarisation, this can lead to an irregular heart beat and sudden death due to ventricular fibrillation.
How many of you learn only what is in the specification and how many of you actually go through all the book (specification plus extra information and applications)? :eek:

How doomed am I, if I just "learn" what is in the specification and "go over/read" the whole book? :eek:
Original post by haydyb123
Long QT syndrome is where the timing between the QRS complex and the T wave is so long that it delays repolarisation, this can lead to an irregular heart beat and sudden death due to ventricular fibrillation.


Thanks:smile::smile:
Reply 2145
Original post by Parthenon93
How many of you learn only what is in the specification and how many of you actually go through all the book (specification plus extra information and applications)? :eek:

How doomed am I, if I just "learn" what is in the specification and "go over/read" the whole book? :eek:


I don't not even look at the learning outcomes, I just go through the whole book.
In fact, i do that for all of my exams.
Got a question,

In the context of the article.

What do we need to know about vectors and adenoviruses.

I'm a bit confused on how this fits into hormones and recombinant dna.

Thanks
it inhabits repolarisation of the heart which means cardiac and stroke volume falls.muscles do not receive enought bloood
Original post by sadbuttrue92
1 question for the article. How would the "long QT syndrome" be fatal??
Reply 2148
Original post by groovygramp
Got a question,

In the context of the article.

What do we need to know about vectors and adenoviruses.

I'm a bit confused on how this fits into hormones and recombinant dna.

Thanks


When inserting the new genes into human body, a vector is used; in the case of the article the vectors are the two viruses; adenoviruses and adenovirus associated viruses. The article basically goes on about how adenovirus associated virus are better that the other as they are smaller, therefore have a greater chance of evading the immune system. This increases the change of the new gene being inserted into the target cells.

What park of hormones are you confused about?
and do you mean recombinant bacteria not DNA
Reply 2149
Original post by Parthenon93
How many of you learn only what is in the specification and how many of you actually go through all the book (specification plus extra information and applications)? :eek:

How doomed am I, if I just "learn" what is in the specification and "go over/read" the whole book? :eek:


A lot of this test is about applying knowledge from the specification, personally all i do is learn the points on the spec and its worked so far
Biology has been my worst subject all through A level haha! I find the exam questions ridiculous. Hopefully we will get a decent paper on Wednesday and our efforts will not have been wasted! How is everyone finding the pre release material?
Original post by abuelzouz
hey guys,... i havent touched any unit5 material since so long... what do i have 2 do today nd tomorrow? except revising book nd notes :s




i dont know why in this forum i need to re-ask the question 3 times.. plus getting a minus rating... isnt it my right to ask questions regarding my exam!! isnt this forum's aim 1!!!
Reply 2152
Original post by sadbuttrue92
1 question for the article. How would the "long QT syndrome" be fatal??


This is a good question, if we think about what the QT part of the electrocardiogram stands for we can sort this question out.

The 3 main part of an ECG are as follows:

P wave - Time taken for atrial systole
QRS complex - Time taken for ventricular systole
T wave - Time taken for the repolarisation of the ventricles during diastole

So the long QT must mean that the time taken for the QRS complex and T wave to happen takes longer. Therefore, we normally say that Long QT increases the time taken for repolarisation.

This may lead to palpations of the heart, fainting or sudden death.

Hope that helped you :tongue:
Reply 2153
Can someone help with a question related to the article?

I have this question and the mark scheme answer below:

Suggest how erythropoietin (epo) might "command the body to manufacture new red blood cells" (5 marks)

MARK SCHEME ANSWER:
-protein;
-binds to receptors on;
-(multipotent) stem cells;
-triggers a series of biochemical reactions inside the cell;
-resulting in production of a substance that;
-attaches to operator region/interacts with or acts as a transcription factor
-switches on genes
-which trigger mitosis;
-or produce proteins which alter structure and or function of cells;
-so they become specialised/differentiated

I'm so confused about this :frown: I thought epo was produced by the kidneys and produces new red blood cells in the bone marrow... so why are they talking about stem cells? wouldn't epo bind to receptors in the bone marrow and cause it to produce more red blood cells? helppp :frown:
Reply 2154
Original post by abuelzouz
i dont know why in this forum i need to re-ask the question 3 times.. plus getting a minus rating... isnt it my right to ask questions regarding my exam!! isnt this forum's aim 1!!!


Make sure you do all the past papers including the specimen one, and make sure you've had a read of the article exexcel gave out.

:wink:
Original post by LibbyU
Can someone help with a question related to the article?

I have this question and the mark scheme answer below:

Suggest how erythropoietin (epo) might "command the body to manufacture new red blood cells" (5 marks)

MARK SCHEME ANSWER:
-protein;
-binds to receptors on;
-(multipotent) stem cells;
-triggers a series of biochemical reactions inside the cell;
-resulting in production of a substance that;
-attaches to operator region/interacts with or acts as a transcription factor
-switches on genes
-which trigger mitosis;
-or produce proteins which alter structure and or function of cells;
-so they become specialised/differentiated

I'm so confused about this :frown: I thought epo was produced by the kidneys and produces new red blood cells in the bone marrow... so why are they talking about stem cells? wouldn't epo bind to receptors in the bone marrow and cause it to produce more red blood cells? helppp :frown:


the bone marrow cells are the haemopoietic STEM CELLS... which epo causes to differentiate INTO reb blood cells.... it may activate and switch certain transcription factors that then go on and activate genes... a good example is the gene coding for the enzyme that produces Haemoglobin
does anyone have a link to some past papers (the only one i have is Jan 2011) or a specimen? they are all secure download only on the edexcel website :smile:
Also, going thru the mark scheme points:

-protein; it is a peptide hormone
-binds to receptors on; found on the cell surface membrane.. peptide hormones have polar groups and thus cant cross cell membrane directly
-(multipotent) stem cells; like i said above, about the Haemopoietic stem cells
-triggers a series of biochemical reactions inside the cell; this is the Protein Kinase Cascade ... signal transduction mechanism... we dont need to know about it...
-resulting in production of a substance that; it uses secondary messengers
-attaches to operator region/interacts with or acts as a transcription factor; self explanatory
-switches on genes; by binding to promoter and easily allowing the formation of the transcription initiation complex
-which trigger mitosis;
-or produce proteins which alter structure and or function of cells; like haemoglobin.... or enzymes that remove the nucleus (remember, red blood cells are enucleated)
-so they become specialised/differentiated
Covers the whole chapter. :eek:
Original post by LibbyU
Can someone help with a question related to the article?

I have this question and the mark scheme answer below:

Suggest how erythropoietin (epo) might "command the body to manufacture new red blood cells" (5 marks)

MARK SCHEME ANSWER:
-protein;
-binds to receptors on;
-(multipotent) stem cells;
-triggers a series of biochemical reactions inside the cell;
-resulting in production of a substance that;
-attaches to operator region/interacts with or acts as a transcription factor
-switches on genes
-which trigger mitosis;
-or produce proteins which alter structure and or function of cells;
-so they become specialised/differentiated

I'm so confused about this :frown: I thought epo was produced by the kidneys and produces new red blood cells in the bone marrow... so why are they talking about stem cells? wouldn't epo bind to receptors in the bone marrow and cause it to produce more red blood cells? helppp :frown:


If it's worth five marks I would just ignore the stem cell bit.
If I got this question I'd talk about epo is a protein which binds to a receptor on a particular cell which causes the activation of a second messenger causing a kinase protein cascade. Which acts as a transcription factor to switch on a gene which causes the structure of RNA to be different which changes the structure of proteins which causes more blood cells to be created.

Pretty much what it states in the book and the examiner's mark schemes are actually massive for alternative answers, markschemes we get are just condensed I believe :smile:. (also stem cells can be found in the bone marrow so maybe that's what it's talking about)

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