Thanks!
When you say ions always use facilitated diffusion, does that means that they never use active transport? (Because they require channel proteins... or because they aren't usually required to be moved against a concentration gradient?) Probably a silly question but just wanted to be sure.
As for the autoimmune diseases, I guess mentioning in an answer that immune response coordinated against the self cells could occur through humoral or cell mediated mechanisms, or both?
You mentioned MS, which is also mentioned in the study design. As it involves the myelin being destroyed which is a covering of nerve cells rather than a cell itself; are Tc cells mounting an attack on nerve cells? Or on the myelin which they treat like an infected cell?
I doubt that we'd need to know all that but now I'm confused (oops). Is it sufficient enough to say that in the case of MS; an adaptive immune response is mounted against body tissue which is incorrectly identified as non self, resulting in damage to the myelin of nerve cells. The immune response may involve the production of antibodies against self antigens by B cells or the activation of Cytotoxic t cells which directly destroy self cells.
Sorry for the confusion !!!
Mechanistically active transport and facilitated diffusion are pretty similar, to be honest, hence the reason I omitted active transport. You're right though, ions can be actively transported.
Yes you could say that both are involved. You wouldn't be expected to know the details of the variety of autoimmune disease out there.
I'm not sure what level of detail you need to know about MS (nobody really does). Our understanding of MS is actually quite poor, but if I remember correctly it's basically the T-helper cells directing an innate immune response against the myelin that causes the problem. There is also involvement from anti-myelin antibodies, which I think would be a more VCE-appropriate thing to say than the innate involvement.
MS is new to the course and it's really unclear what you actually need to know about it, so sorry about the half-arsed answer...I can only tell you what I know to be true about MS, not the VCE version of it!
This question keeps irritating me and i don't get a way through it. What is the mode of transport for neurotransmitters? I simply answered that they travel through synapse/synaptic gap but i knew this wasn't the answer. According to solutions, the answer was diffusion. Can anyone help me out? Anyways it was a NEAP 2017 SA question.
They're released by exocytosis and subsequently diffuse across the synaptic cleft to the post-synaptic neuron.