Greippi

I don't know for definite, but I would just assume that the genes are different sizes depending on the species. It's the same gene, but I assume the genes/gene products are slightly different sizes. The "S" refers to the Svedburg unit of molecular size, referring to the weight at which molecules sediment in centrifuges.

Yes, I was speaking about T-helper cell dependent, although I did mention the independent activation as well. Yes, there are quite a few more subtypes (at present I know of of 4 others, but I wouldn't be surprised if more will be discovered) of T cell (and indeed, B cell). They bind different sorts of antigen presented in different ways. For example, natural killer T-cells are a bridge between the innate and the adaptive immune responses. T memory cells persist after infection as part of the memory component of the immune system.

Is a cofactor technically part of an enzyme though?

Do you want to find the RATE of the reaction, or do you want to pick a time and be able to make a guess at the substrate concentration at that time? Would it not just be the standard M-M equation? i.e. plot substrate conc verses time, from which you can find Vmax and Km (maybe easier to do a Lineweaver-burke plot here), then plug the values in to the M-M equation to get v?

Well, defining pH would be a good start to getting you on the right track. What is pH a measure of?...although mr wombel's done that for you.

One idea I came up with was make it sneeze fluorescent protein. Maybe give it elevated levels of IgE so it's sensitive to allergens and prone to sneezing!

You could use thermostable proteins from bacteria that live by deep sea vents. Or how about some sort of mucous that contains xanthan gum, which is reasonably flame resistant.

What sort of catalyst? Where would the methane come from?

There.

"Utilising your experience and knowledge of biochemistry/genetics/molecular biology, describe how you would go about designing a fire-breathing dragon?" (One of the final exams for third year biochemistry is a 2 hour essay question that's meant to cover everything you've ever learnt on the degree course. We got the specimen paper for it today, this was one of the option questions. So we just spent a merry afternoon discussing how we would go about answering this question.) I'll post what I came up with later.

The electrolysis of sodium chloride. A reaction that would produce chlorine gas, it's not difficult (not particularly safe though).

While amusing, that won't get you any marks. They're looking for you to give them an example of a basic residue. A nucleus isn't a functional group. Not in biochemistry anyway.

Making it yourself is a lot more effort than just buying some. There are various reactions that will produce HCl as a gas, which you could collect and bubble through water to dissolve it. However, unless you have proper equipment and do it right that could get pretty dangerous. I wouldn't recommend attempting any electrolysis methods though that's just asking for disaster. EDIT: I just did a quick search of these forums, there are plenty of threads on this topic actually.

That would work! Make sure you drink lots of water though - we want to get thin, not desiccated.

If this isn't a joke then I apologise for laughing my face off: the "hot" that is used to describe a spice is a different sort of hot that a fire produces. Fat cells aren't burnt by combustion any way - they're a chemical store of energy and the fat is broken down by chemical reactions involving enzymes. Although as the previous post said there may be some merit to some spices, but I don't know anything about that.

There are two types of T cell - T helper cells and cytotoxic T cells. B cells recognise free native antigen, stuff that's wandering around e.g. in the blood. The B cells then differentiate in to plasma cells to produce loads of soluble antibody to "get" the antigen. However, B cells often need T cell help to differentiate. In this case, The B cell presents the antigen to the T helper cell - so in this case the T helper cell recognises the same antigen as the B cell, with the condition that the antigen is presented by the B cell. The T helper cell then activates other immune cells to do their job in getting rid of the infection. There are circumstances where B cells can differentiate on their own, for example when they encounter really common stuff - like the repeating carbohydrate units on a bacterial cell. Cytotoxic T cells recognise and kill infected host cells. When a cell of the body gets infected by something like a virus, often the molecules on the cell surface change to indicate to the T cells that there's an infection. So, you see here there's a major difference in the types of antigen that are recognised by the different cell types. And THAT is how it works in a nutshell. Hope that helped.

Oooh enzymes. Okay, well first: what does a base do? Although, it's even simpler than that: What makes up the functional groups in an enzyme? An enzyme is basically a long protein strand folded up. So what are the units that make up this protein strand? Once you've found out these basic building blocks, you'll find that practically anywhere you look for a list of them, it will be divided up by type (i.e. basic, acidic...)

I have some of those. I stick stuff to the fridge with them then my housemates get baffled as to why they can't get them OFF the fridge.

Okay, this is just speculation and half-asleep musing BUT: isn't it useful that the bacteria get some of their energy from something that we can't digest on our own? Otherwise they would be 'taking energy away from us', thus making the system less efficient.

I worked in this lab last semester: No fancy equipment, each bit of exciting equipment gets its own room. For example, our X-ray machine: Hopefully I'll work with the NMR lab sometime

I suppose you could loosely describe it as such. Really? The diversity created by evolution is surely an increase in entropy. The processes within a living cell are all thermodynamically viable, satisfying the laws related to entropy.

Put very simply, it slows the function of the brain by inhibiting the activity of glutamate on certain receptors in the brain. Usually glutamate would increase or excite brain activity. There are other mechanisms as well, but that's the most basic.

A major area of research right now is the actual architecture of photosynthetic membranes. Turns out the arrangement of the photosynthetic complexes in the membrane plays a vital role in the efficiency of the system. The more we know about this, the more effectively we can create an artificial system. If anyone's interested I have quite a few references on the topic.

Or maybe it was covered by glass, or some sort of clear substance. Maybe people in that age weren't familiar with a material THAT clear so to them it looked like nothing. Having said that, I think it's unlikely that intelligent life lurks out there, or at least that it's got anywhere close to Earth.

I don't know about that. I thought pitchblende was mainly UO2 (uranium (IV) oxide)and UO3 (uranium (VI) oxide) (with other oxides in there too).