AQA AS Biology Unit 1

what do we need to know about monoclonal antibodies?

Reply 41

Original post by Ann1234

That's what i put too, the ribosomes look confusing because there's some small circles and then just some dots lol
Anyway, thank you for your help :smile:

I have another question i need help with
http://filestore.aqa.org.uk/subjects/AQA-BIOL1-W-QP-JAN11.PDF
Q5b -the answer is 4cm^3 and 16cm^3.. don't understand how though?

You can use the formula c1v1=c2v2 where c is conc. and v is volume.

C1 is 1.0
C2 is 2.0
and V2 is 20

All you do now is rearrange that formula to find V1 (0.2x20)/1 which gives you 4 cm3 of solution and the other 16 cm3 is water

Hope that helps! :smile:

Reply 42

katt123

1

Original post by frankiejayx

what do we need to know about monoclonal antibodies?

We need to be able to explain how they are produced:
1. A mouse is exposed to non self material against which an antibody is required
2. The Bcells in the mouse produce a mixture of antibodies(polyclonal) which are extracted from the mouse's spleen
3. To enable these Bcells to divide outside the body - they are mixed with cells that divide readily outside e.g. cells from a cancer tumour
4. Detergent is added to the mixture to break down the cell surface membrane of both the cells - so they can fuse together
5. These fused cells are separated under a microscope and each single cell is cultured to form a clone - each one is then tested on to see if the antibody is produced - if it does - grown on a large scale + antibodies extracted from the growth medium
6. Monoclonal: because these are antibodies come from cells cloned from a single Bcell

Need to be able to give the uses in medicine and science:
1. Immunoassay: Calculates the amount in a substance - e.g. in pregnancy tests
2. Cancer treatment: Monoclonal antibodies can be made so that they attach onto only cancer cells - activate a cytotoxic drug - which kills them
3. Transplant surgery: To prevent rejection - specific Tcells are knocked off

Reply 43

Maths_Freak123

6

Original post by Ann1234

That's what i put too, the ribosomes look confusing because there's some small circles and then just some dots lol
Anyway, thank you for your help :smile:

I have another question i need help with
http://filestore.aqa.org.uk/subjects/AQA-BIOL1-W-QP-JAN11.PDF
Q5b -the answer is 4cm^3 and 16cm^3.. don't understand how though?

this is a similar question i did in my ISA paper-we know from the question that it will add up to 20cm^3. 0.2moldm^3 of NaCl solution is 20% of 1moldm^3. so the volume will be 20% of 20cm^3 which is 4cm^3. To work out the remaining volume of distilled water is just 20 - 4 which is 16.

Reply 44

WannaGetAnA

11

Hey guys

im resitting bio unit 1 and 2 (and I did the ISA too). I got a C last year, and want to improve to at least a B.

I'm gonna join on the Q and A thing:

Explain how a vaccine can lead to a person developing immunity to a disease. (5)

Reply 45

Original post by WannaGetAnA

Hey guys

im resitting bio unit 1 and 2 (and I did the ISA too). I got a C last year, and want to improve to at least a B.

I'm gonna join on the Q and A thing:

Explain how a vaccine can lead to a person developing immunity to a disease. (5)

The vaccine consists of an antigen or an attenuated pathogen and when it enters the body it triggers the immune response. The T cells activate the B cells which undergo mitosis to form plasma cells. The B cells produce antibodies, and develop into memory cells. On the second exposure, more antibodies are produced and even rapidly which can destroy the pathogen by coating it making it easier to be engulfed by phagocytes. :smile:

Describe the transmission of the TB bacterium (5)

Reply 46

Original post by katt123

I'm in on this! Shall I start off - Describe how proteins are arranged in a plasma membrane and the part they play in transporting substances into and out of a cell?

Ooh I really don't like this question. Proteins are essentially scattered across the phospholipid bilayer that makes up the plasma membrane and vary in shape and size hence mosaic. There are two types: intrinsic proteins and extrinsic proteins. Intrinsic proteins completley span the phospholipid bilayer from one side to another forming water soluable protein channels and carrier proteins enabling faciliated diffusion and active transport to take place.(And then just essentially talk about how faciliated diffusion takes place and AT).Would that be correct?

Reply 47

Aysha97

Original post by taaaaahira

Immunity is horrible, I don't mind the other topics! I don't like lung diseases as well

Posted from TSR Mobile

I agree worst topic

Posted from TSR Mobile

Reply 48

Original post by PharmacyDoctor

Ooh I really don't like this question. Proteins are essentially scattered across the phospholipid bilayer that makes up the plasma membrane and vary in shape and size hence mosaic. There are two types: intrinsic proteins and extrinsic proteins. Intrinsic proteins completley span the phospholipid bilayer from one side to another forming water soluable protein channels and carrier proteins enabling faciliated diffusion and active transport to take place.(And then just essentially talk about how faciliated diffusion takes place and AT).Would that be correct?

Yep, don't forget to mention the receptor proteins that help cells to respond to certain chemicals i.e hormones etc

Reply 49

Original post by HannahRudd-19

Er, there's intrinsic proteins which span the length of cell-surface member and extrinsic proteins which are only partly embedded in the membraneThey allow the facilitated diffusion of water molecules and lipid-souble substances through the membrane. Glycoproteins and glycolipids also act as receptor sites to allow hormones across the membrane too, for exampleIs this rught?Describe the heart cycle...

Are you sure glycoproteins and glycolipids ALLOW for hormones ACROSS the plasma membrane? My understanding of glycoproteins is they act as a rechognition site for specific chemicals i.e. hormones by identifiying cells and the glycolipids was to act as a rechognition site e.g. for cholera toxins by identifiying cells. When the glycolipids work in CONJUNCTION with extinsic proteins then its acts as cell receptors for specific molecules/chemichals i.e. the hormones. But even then it does not transport hormones across the membrane.

Reply 50

kkboyk

21

Original post by Gully97

I hope that the data based questions are straightforward for once

Haha, it's AQA of course it won't :tongue:

Reply 51

kkboyk

21

I'm too busy dreading over unit 2... the mark scheme is just horrible -.-

Reply 52

Original post by ThatMadClown

The vaccine consists of an antigen or an attenuated pathogen and when it enters the body it triggers the immune response. The T cells activate the B cells which undergo mitosis to form plasma cells. The B cells produce antibodies, and develop into memory cells. On the second exposure, more antibodies are produced and even rapidly which can destroy the pathogen by coating it making it easier to be engulfed by phagocytes. :smile:

)

So when the dead pathogens are injected into the body does it result in a cell mediated response first or a humoral respoal? I would have though humoral right? Because the pathogen is not in any of the body cells?

Reply 53

Original post by PharmacyDoctor

So when the dead pathogens are injected into the body does it result in a cell mediated response first or a humoral respoal? I would have though humoral right? Because the pathogen is not in any of the body cells?

You could say humoral because of the involvement of antibodies, but I don't think you need to say that, as long as you talk about the activation of B and T cells and how that leads to a rapid secondary response, you should be fine. :smile:

Reply 54

Original post by ThatMadClown

You could say humoral because of the involvement of antibodies, but I don't think you need to say that, as long as you talk about the activation of B and T cells and how that leads to a rapid secondary response, you should be fine. :smile:

Cheers

. Would you mind checking out question 7(c) of this paper for me: http://filestore.aqa.org.uk/subjects/AQA-BIOL1-QP-JUN13.PDF I just can't understand how they come to the answer!

Reply 55

The mark scheme is as follows for that question: 1. (Vaccine contains) antigen/attenuated/dead pathogen;2. Microfold cells take up/bind and present/transport antigen (to immune system/lymphocytes/T-cells);3. T-cells activate B-cells;4. B-cells divide/form clone/undergo mitosis;5. B-cells produce antibodies;6. Memory cells produced;7. More antibodies/antibodies produced faster in secondary response/on reinfectionI can't undertstand BULLET POINT 2. Why are the microvilli cells taken to T-cells instead of the B-cells? Thought it was a humoral response not a cell mediated...

Reply 56

sure, basically they're testing out microfold cells. The antigens bind to the microfold cells, so when the antigen is placed in a vaccine, they end up binding with the cell itself (which is also in the vaccine). From then on its just like any other immune response process, the T cells are activated first, the B cells second, which then divide by mitosis to produce plasma cells, and then the antibodies etc..

Its best if you learn the process of immunity, how it starts from phagocytosis all the way to the production of memory cells and then antibodies, if you learn the process you can apply it to anything :smile:

Reply 57

Original post by ThatMadClown

sure, basically they're testing out microfold cells. The antigens bind to the microfold cells, so when the antigen is placed in a vaccine, they end up binding with the cell itself (which is also in the vaccine). From then on its just like any other immune response process, the T cells are activated first, the B cells second, which then divide by mitosis to produce plasma cells, and then the antibodies etc.. Its best if you learn the process of immunity, how it starts from phagocytosis all the way to the production of memory cells and then antibodies, if you learn the process you can apply it to anything :smile:

That's kind of what I dont understand!. I know the exact process for; Phargocytosis, Cell Mediated Immunity, and Humoral immunity but just can't see the way in which they are interlinked. Would you care to explain?

Reply 58