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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: emmawatsonlover990 on April 25, 2019, 12:43:44 pm

Title: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 12:43:44 pm
Hi,

I was wondering if anyone knew the answer to this question. The question is about Signalling Molecules.

Question: Give an example of how a signalling molecule may be used in an immune response in an animal.

Thanks in Advance.

Bellatrix Lestrange :D
Title: Re: Signalling Molecules
Post by: darkz on April 25, 2019, 12:46:40 pm
Hi,

I was wondering if anyone knew the answer to this question. The question is about Signalling Molecules.

Question: Give an example of how a signalling molecule may be used in an immune response in an animal.

Thanks in Advance.  :D

When you think of the immune system, you should immediately think about cytokines (broadly, you can refer to them as being the signalling molecules of the immune system). Hence, think of interferons (combating viruses), or their use in inflammation (preventing the spread of infection), etc.
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 02:08:49 pm
Thank you so much. This helped so much. This is greatly appreciated.

Thanks,

Bellatrix Lestrange  ;) ;) ;)

Hi again,

Another Question

Question: Outline the difference in how the two main types of signalling molecules interact with cells.

Thanks in advance,

Bellatrix Lestrange  :D

Mod edit (PF): Merged posts
Title: Re: Signalling Molecules
Post by: darkz on April 25, 2019, 05:08:38 pm
Hi again,

Another Question

Question: Outline the difference in how the two main types of signalling molecules interact with cells.

Thanks in advance,

Bellatrix Lestrange  :D

For the VCE course, the main types are hydrophobic and hydrophilic signalling molecules
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 05:18:31 pm
Thank you so much. I should have known the answer. Hydrophilic and Hydrophobic. The differences in how they interact with cells.

Bellatrix Lestrange  ;) ;) ;)
Title: Re: Signalling Molecules
Post by: DBA-144 on April 25, 2019, 05:24:49 pm
darkz is certainly the better person to answer this question, but I though that I might also have a go at these, if that's ok.

For your first question, cytokines are the main signalling molecules in the immune system/responses. Examples of immune responses caused by cytokines involve interferons, activation of the inflammatory response, like darkz has said, as well as the release of cytokines (eg. interleukin) by T helper cells to activate and induce cytotoxic T cells and B cells to replicate, in the adaptive immune response, or the release of histamine and prostaglandins by mast cells, when they get damaged. All of these are examples of immune responses caused by specific signalling molecules.

As for your second question, you may also like to refer to the hydrophobic nature of signalling molecules and where the receptors for these molecules are i.e inside or on the surface of the cell.

I know that darkz answered your questions already, but still :P   

Edit: finished and then noticed there was already a reply from OP lol
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 05:35:42 pm
Sorry to annoy anyone, but I was wondering if anyone knew what second messengers are.

Thanks in advance,

Bellatrix Lestrange  ;) ;) ;)
Title: Re: Signalling Molecules
Post by: Owlbird83 on April 25, 2019, 06:20:28 pm
Sorry to annoy anyone, but I was wondering if anyone knew what second messengers are.

Thanks in advance,

Bellatrix Lestrange  ;) ;) ;)

When the signalling molecule is hydrophillic and can't cross the cell membrane so it binds to the outside of the target cell on a receptor in the cell membrane. This binding to it causes second messenger molecules to be released inside the cell which travel to the necessary parts inside the cell or cause a signal cascade. There are many second messenger molecules released inside the cell which amplifies the signal.
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 06:45:31 pm
Thank you for your help.

I have another question.

Question: (Screen Shot)

Thanks in advance.

Bellatrix Lestrange  :) ;) :D
Title: Re: Signalling Molecules
Post by: vox nihili on April 25, 2019, 06:49:31 pm
Thank you for your help.

I have another question.

Question: (Screen Shot)

Thanks in advance.

Bellatrix Lestrange  :) ;) :D

Please try to do the question yourself first! You won't learn anything if we just complete it for you
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 07:09:57 pm
Thanks. I just re-read some of my notes and also parts of the textbook and I have answered it.

Bellatrix Lestrange  :-[ :-[ :-[ :)

I am not sure about what signalling molecules are hydrophobic and which ones are hydrophilic.  :-\ :-\ :-\ :( ;)

Bellatrix Lestrange

Mod edit: Merged posts
Title: Re: Signalling Molecules
Post by: darkz on April 25, 2019, 08:17:13 pm
I am not sure about what signalling molecules are hydrophobic and which ones are hydrophilic.  :-\ :-\ :-\ :( ;)

Bellatrix Lestrange

You don't need to know specific examples of hydrophobic and hydrophilic molecules - if they're talking about the polarity of a molecule, then they should give it in the question stem, or at least, provide other information which you can use to deduce its polarity.

e.g. if a molecule can pass through the plasma membrane => conclude that it is a hydrophobic signalling molecule
       binds to an intracellular receptor => conclude that it is a hydrophobic signalling molecule

etc
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 08:27:57 pm
Thanks darkz

Bellatrix Lestrange
Title: Re: Signalling Molecules
Post by: emmawatsonlover990 on April 25, 2019, 09:56:42 pm
Why are some cancers resistant to the radiation and chemical treatments that would kill healthy cells.

Thanks in advance.

Bellatrix Lestrange  ;)  ;)  ;)
Title: Re: Signalling Molecules
Post by: Sine on April 25, 2019, 10:16:11 pm
Why are some cancers resistant to the radiation and chemical treatments that would kill healthy cells.

Thanks in advance.

Bellatrix Lestrange  ;)  ;)  ;)
As suggested by Vox earlier, please try to go through your own thinking first (and even research) and share this. This will greatly benefit you in the long term.

Title: Re: Signalling Molecules
Post by: Gianni Farfaglia on May 18, 2019, 10:44:44 am
Why are some cancers resistant to the radiation and chemical treatments that would kill healthy cells.

Thanks in advance.

Bellatrix Lestrange  ;)  ;)  ;)

Hi Bellatrix, there might be many reasons why some cancers are radiation resistant. I don't think at  a VCE level we really have to explore too much the specifics why this might be the case. However a way in VCE context you might think about it is there may be possible dysfunction of certain signalling molecules involved in the cells intrinsic apoptotic pathway and as a result DNA damaging radiation which otherwise may have triggered cell apoptosis may not cause apoptosis.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5914062/
here's a review paper exploring some of the ideas involved for interest but really from a VCE perspective just focus on my point above.