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    If your stuck on something for tomorrow's exam, feel free to ask me, I can help you and go through anything ☺
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    (Original post by doctordee)
    If your stuck on something for tomorrow's exam, feel free to ask me, I can help you and go through anything ☺
    Thanks!! Not really stuck but it's just soooo much to know I'm gonna do a few more past papers in a bit, so the questions i get wrong can I ask you if i don't understand it?

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    (Original post by cheetahs56)
    Thanks!! Not really stuck but it's just soooo much to know I'm gonna do a few more past papers in a bit, so the questions i get wrong can I ask you if i don't understand it?

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    Yes of course you can,
    Try not to stress out about it.
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    (Original post by doctordee)
    If your stuck on something for tomorrow's exam, feel free to ask me, I can help you and go through anything ☺
    hi doc,

    could you please explain about tb, the sorts of things we could get asked?
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    4th time doing....any tips?
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    (Original post by mufc_chica)
    4th time doing....any tips?
    What did you get the other times?
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    (Original post by omnom)
    hi doc,

    could you please explain about tb, the sorts of things we could get asked?
    Thanks for calling me doc, but I'm just a normal student like you

    TB.
    Let me tell you what you need to know, and then you can try and guess the questions.

    You need to know that TB is spread through droplets, it is a disease that can be passed on so easily i.e by speaking to someone who has it. It tends to be more common in areas that are overcrowded, it can be prevented with a BCG vaccination and can be treated with antibiotics which is is important that the individual takes the full course to prevent resistant bacteria forming. Common symptoms on TB include harsh coughing, tiredness and loss of appetite.

    You will need to know this part more than anything, the course, above I told you about the symptoms and transmission but the course can be a 5 mark question so here goes a perfect 5/5 mark answer.

    So when a person becomes infected with the TB bacterium the bacteria grows and divides in the upper region of a persons lungs in which there is a large supply of oxygen. The immune response begins and white blood cells accumulate at the site of infection and this causes inflammation and enlargement of the lymph nodes that drain that area of the lungs, this is more common in children.

    In a healthy person there are few symptoms if any but however years later the bacteria may re-emerge and this can be even worse. The TB can spread to the rest of the body and the TB can damage the lungs so fatally that they will be so heavily scarred and an individual may behin to cough up their own lung tissue (GROSS).

    That is all you will ever need to know about TB.
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    (Original post by doctordee)
    Yes of course you can,
    Try not to stress out about it.
    Thank you

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    I'm going to give you a 5/5 mark answer.
    You don't need to know too much about this so I'm not going to go crazy and in-depth.

    The mechanism in which glucose is absorbed through the small intestines is called co-transport because it involves two molecules. Due to active transport of sodium ions from the epithelial cells by the sodium-potassium pump, into the blood there is a higher concentration of Na+ in the lumen of the small intestine than the epithelial cells. The sodium ions will then diffuse into the epithelial cells DOWN a concentration gradient through a co-transport protein in the cell-surface membrane. As they flood through this carrier protein they couple up (awwww) with some lonely glucose molecules and carry them into the cell with them, the glucose passes into the blood plasma by facilitated diffusion after this. Sodium ions move DOWN their concentration gradient but glucose molecules move UP their concentration gradient and this is why they need the sodium ion to power their movement through the cell. This makes it an indirect form of active transport as it is Na+ not ATP directly aiding the movement of the glucose molecules.

    Okay so I may have gone on a bit there but if you really want full marks I would try and get all of that in and you will be sure to have full marks. A lot of people have been asking me for this so I thought I would post this on here.
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    (Original post by doctordee)
    I'm going to give you a 5/5 mark answer.
    You don't need to know too much about this so I'm not going to go crazy and in-depth.

    The mechanism in which glucose is absorbed through the small intestines is called co-transport because it involves two molecules. Due to active transport of sodium ions from the epithelial cells by the sodium-potassium pump, into the blood there is a higher concentration of Na+ in the lumen of the small intestine than the epithelial cells. The sodium ions will then diffuse into the epithelial cells DOWN a concentration gradient through a co-transport protein in the cell-surface membrane. As they flood through this carrier protein they couple up (awwww) with some lonely glucose molecules and carry them into the cell with them, the glucose passes into the blood plasma by facilitated diffusion after this. Sodium ions move DOWN their concentration gradient but glucose molecules move UP their concentration gradient and this is why they need the sodium ion to power their movement through the cell. This makes it an indirect form of active transport as it is Na+ not ATP directly aiding the movement of the glucose molecules.

    Okay so I may have gone on a bit there but if you really want full marks I would try and get all of that in and you will be sure to have full marks. A lot of people have been asking me for this so I thought I would post this on here.

    Thanks for the answers in the previous thread do you have any tips on how to tackle how science works questions and apply knowledge?

    Finally,could you please go through the process of phagocytosis,T-cells and B-cells please
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    (Original post by FutureMedic1009)
    Thanks for the answers in the previous thread do you have any tips on how to tackle how science works questions and apply knowledge?

    Finally,could you please go through the process of phagocytosis,T-cells and B-cells please
    I personally never read the passages and just answer the questions based on what I know unless it states that the answer is in the passage.

    Also,
    Okay, I used to hate it to but now I love these,
    Let me tell you all that you need to know on this.

    The order of immunity -
    1) Phagocytosis,
    2) T-Cells
    3) B-Cells.

    So it all starts with phagocytosis and this involves a white blood cell called a phagocyte. Pathogens produce chemicals and these attract a phagocyte, when a phagocyte approaches the pathogen it will engluf it and a phagosome will form, the lysosomes within the phagocyte will now release their lytic enzymes into the phagosome and this will break down the pathogen. The soluble products from the breakdown will be absorbed into the cell membrane and other parts will then be presented on the phagocytes surface to activate T-cells.

    T-Cells will kill the infected cells that took part in phagocytosis and divide into more T-cells and they will even stimulate B-cells.

    B-cells are grouped by plasma and memory cells.
    Plasma cells secrete antibodies and memory cells remember specific antigens and will recognise them a second time round in which the response will then be secondary if the antigen is seen again rather than primary.

    I answered that part previously on the other thread.
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    For the questions like work out heart rate or cardiac output
    How do you work it out?

    For example q6c June 11
    Thanks


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    Really confused about the Na+ K+ Pump and how it all works could you please explain?
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    (Original post by doctordee)
    If your stuck on something for tomorrow's exam, feel free to ask me, I can help you and go through anything ☺
    Test for starch and reducing sugars? Any tips for HSW questions too?

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    (Original post by dooobie_)
    Test for starch and reducing sugars? Any tips for HSW questions too?

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    Test for Starch
    Add Iodine dissolved in Potassium Iodide Solution and If there is starch it will turn from a almost Orange colour to a Dark Blue or Black

    Test For Reducing suars
    Benedicts reagent test. Crush up your sample, then add Benedicts reagent which is blue, heat the sample and if it forms a brick red precipitate then it contains reducing sugars.

    Hope this helped
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    (Original post by dooobie_)
    Test for starch and reducing sugars? Any tips for HSW questions too?

    Posted from TSR Mobile
    Test for starch -
    just add iodine dissolved in potassium iodide solution to the test sample.
    If there is start present then the sample will change from a orangey colour to a blue-black colour.

    Test for reducing sugars -
    Add 2cm(cubed) of the sample your testing into a beaker, if it is not already in liquid form them add water and mush mush mush!
    Then add an equal amount of Benedicts reagent to the test tube, boil it in a water bath for 5 minutes and then take it out, if a reducing sugar is present then the solution will turn a orangey-red colour.

    I always answer the HSW questions by not looking at the passage and just answering it based on what you know, I find the passages irrelevant unless it states the answer is there.
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    Many of you are asking me about heart disease so I have prepared this for you,
    Everything you will ever need to know!

    Okay so CHD affects the coronary arteries that supply the heart muscle itself with the nutrients it needs ie oxygen and glucose which is required for respiration. Atheromas form and these can lead into Thrombosis or an Aneurysm.

    But first I'm going to explain what a hear attack is, this is when a area of the hear suffers from deprivation of blood and the oxygen in the blood that it requires. This is due to a blockage in the artery called an atheroma. Atheromas are fatty deposits that build up in the wall and soon become accumulated with LDLs. The atheroma plagues can bulge into the lumen of the artery and then this will restrict blood flow through the artery and increase the pressure within the walls and they try to get the same volume of blood through a tighter space.

    1 - Thrombosis - this is when the atheroma breaks through the endothelium lining of the blood vessel and then this interrupts the smooth blood flow through the vessel and can result in a blood clot or a thrombus. The thrombus can interrupt the blood flow so much that it will be unable to supply blood to the tissues beyond it and so the tissues will die on starvation of oxygen and glucose they they very much need and a thrombus can even carry itself from its origin and lodge itself in another artery (annoying little thing).

    2- Aneurysm - atheromas can weaken the walls of a vessel and then make it swell to form a balloon like blood filled structure in the wall called an aneurysm. Aneurysms can burst leading to haemorrhage and therefore loss of blood to form the region of the body served by the artery. A brain aneurysm is known as a stroke.
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    (Original post by James_Prothero)
    Really confused about the Na+ K+ Pump and how it all works could you please explain?
    I'm going to give you a 5/5 mark answer.
    You don't need to know too much about this so I'm not going to go crazy and in-depth.

    The mechanism in which glucose is absorbed through the small intestines is called co-transport because it involves two molecules. Due to active transport of sodium ions from the epithelial cells by the sodium-potassium pump, into the blood there is a higher concentration of Na+ in the lumen of the small intestine than the epithelial cells. The sodium ions will then diffuse into the epithelial cells DOWN a concentration gradient through a co-transport protein in the cell-surface membrane. As they flood through this carrier protein they couple up (awwww) with some lonely glucose molecules and carry them into the cell with them, the glucose passes into the blood plasma by facilitated diffusion after this. Sodium ions move DOWN their concentration gradient but glucose molecules move UP their concentration gradient and this is why they need the sodium ion to power their movement through the cell. This makes it an indirect form of active transport as it is Na+ not ATP directly aiding the movement of the glucose molecules.

    Okay so I may have gone on a bit there but if you really want full marks I would try and get all of that in and you will be sure to have full marks. A lot of people have been asking me for this so I thought I would post this on here.
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    (I'm not trying to hijack your thread, it's just answering questions is good revision for me too and you never know, some people may not understand what you or I write individually.)

    (Original post by doctordee)
    Thanks for calling me doc, but I'm just a normal student like you

    TB.
    Let me tell you what you need to know, and then you can try and guess the questions.

    You need to know that TB is spread through droplets, it is a disease that can be passed on so easily i.e by speaking to someone who has it. It tends to be more common in areas that are overcrowded, it can be prevented with a BCG vaccination and can be treated with antibiotics which is is important that the individual takes the full course to prevent resistant bacteria forming. Common symptoms on TB include harsh coughing, tiredness and loss of appetite.

    You will need to know this part more than anything, the course, above I told you about the symptoms and transmission but the course can be a 5 mark question so here goes a perfect 5/5 mark answer.

    So when a person becomes infected with the TB bacterium the bacteria grows and divides in the upper region of a persons lungs in which there is a large supply of oxygen. The immune response begins and white blood cells accumulate at the site of infection and this causes inflammation and enlargement of the lymph nodes that drain that area of the lungs, this is more common in children.

    In a healthy person there are few symptoms if any but however years later the bacteria may re-emerge and this can be even worse. The TB can spread to the rest of the body and the TB can damage the lungs so fatally that they will be so heavily scarred and an individual may behin to cough up their own lung tissue (GROSS).

    That is all you will ever need to know about TB.
    There's no way you'd get 5 marks for that. Even though what you've said is true if you wrote all of that for whichever year they asked a 5 marker on TB you wouldn't have got more than 2/3 marks.

    You need to say:
    - TB is spread in droplets from people with TB coughing / sneezing
    - The bacteria then enters the lungs where it is enclosed in semi-solid tubercles by white blood cells, where the bacteria remains alive but inactive (dormant / non-replicating)
    - Then, when the person's immune system is suppressed the bacteria escape from the tubercles where they break down the alveoli, lowering the SA where gas exchange (diffusion) can occur and also cause scar tissue to form. The bacteria can then spread to other regions of the body

    (Original post by James_Prothero)
    Really confused about the Na+ K+ Pump and how it all works could you please explain?
    The NA/K pump is used in absorption of glucose. I think the important way with this is to find a constant starting point and always explain what's cracklackin from that point:

    - Na is actively transported out of the epithelial cell and into the blood via the Na/K pump and this lowers the concentration of NA in the cell. This is all you need to know about the NA / K pump in year 12. For AS you learn about it in depth, about how man NA / K ions it pumps in etc but for AS that is all you need to know.
    - This causes NA from the intestine to move by co transport into the epithelial cell. NA is coupled with glucose and so the two move into the epithelial cell together through the NA / glucose co transport protein (symport).
    - Glucose then leaves the epithelial cell and enters the blood via facilitated diffusion through a channel protein.
    - Circulation removes blood with high NA / glucose concentration and is replaced with blood lowering in concentration. This maintains a steep concentration gradient and the process repeats.
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    (Original post by Neon-Soldier32)
    (I'm not trying to hijack your thread, it's just answering questions is good revision for me too and you never know, some people may not understand what you or I write individually.)



    There's no way you'd get 5 marks for that. Even though what you've said is true if you wrote all of that for whichever year they asked a 5 marker on TB you wouldn't have got more than 2/3 marks.

    You need to say:
    - TB is spread in droplets from people with TB coughing / sneezing
    - The bacteria then enters the lungs where it is enclosed in semi-solid tubercles by white blood cells, where the bacteria remains alive but inactive (dormant / non-replicating)
    - Then, when the person's immune system is suppressed the bacteria escape from the tubercles where they break down the alveoli, lowering the SA where gas exchange (diffusion) can occur and also cause scar tissue to form. The bacteria can then spread to other regions of the body



    The NA/K pump is used in absorption of glucose. I think the important way with this is to find a constant starting point and always explain what's cracklackin from that point:

    - Na is actively transported out of the epithelial cell and into the blood via the Na/K pump and this lowers the concentration of NA in the cell. This is all you need to know about the NA / K pump in year 12. For AS you learn about it in depth, about how man NA / K ions it pumps in etc but for AS that is all you need to know.
    - This causes NA from the intestine to move by co transport into the epithelial cell. NA is coupled with glucose and so the two move into the epithelial cell together through the NA / glucose co transport protein (symport).
    - Glucose then leaves the epithelial cell and enters the blood via facilitated diffusion through a channel protein.
    - Circulation removes blood with high NA / glucose concentration and is replaced with blood lowering in concentration. This maintains a steep concentration gradient and the process repeats.
    Sorry but YOU WOULD get full marks for that, my Dad marks Biology exam papers and seeing as your just a candidate I am sure that he is right and you are wrong.
 
 
 
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