AQA BIOL1 ~ 14 May 2012 ~ AS Biology

Thank you that was the question i was looking at

'that specific?' Bro, this was in one of the old mark schemes for years ago - for an AS exam. How do you know if you don't have to be that specific?

Use it if you want, I don't care. If you think you have a better answer (lol), then put that.



That's a bit of a contradiction. He asks about the cardiac (heart) cycle, and you say 'nothing, you just need to know about the heart.' Nice work.




You should know about how the cardiac cycle is controlled, valves in the control of blood flow, systole & diastole. Also how to calculate cardiac output.

But then why does the other curve keep rising? It's to do with temperature denaturing the enzyme but what I don't understand is why it isn't denatured at the start?

Yes you're right. The graph talks about the mass of product formed. The graph plateaus because of the denaturisation of the enzyme but the mass of product does not decrease-it stays the same. If the graph depicted enzyme substrate complexes formed then the graph would increase then decrease.

hey what points do i need to know about lactose intolerance?

Because at 50˚C the enzyme and substrate have more kinetic energy. Thus there are more successful collisions between enzyme and substrate. Therefore, enzyme-substrate complexes form more quickly and thus the products are formed more quickly. Thus, the graph plateaus before the 30˚C one.

I'm not saying they don't exist haha I'm saying in terms of the specification.

Molybdenum for example is a nutrient which reduces nitrates during the synthesis of amino acids, but we don't need to know about it yet.

Wait I think percentage increase you do change/ old value x 100 and to find out how many times something has increased you just do the new value divided by the old value.. am I right? Just want to check!

The enzyme isn't denatured. If it was denatured, no product would form.

To work out percentage increase use this formulae:

(Initial value - final value) / initial value = your result, times that value by 100 to get a percentage

NOTE: as this is percentage increase when you take your initial value from the final value you should most likely get a minus value, but that's fine in the answer just write down the positive value

Just incase you don't understand i'll give an example, say for example my initial value was 5, and my final value was 10, you would do this:

5 - 10 = -5

- 5 / 5 = -1

-1 x 100 = -100

ignore the minus sign and just put 100%

(as we can easily tell 5 to 10 is obviously a 100% increase anyways but lets hope you understand it.)

Essentially, macrophages are phagocytes. However, phagocyte is a broad generic that could be for many other cells. Specifically, according to a set of notes my teacher gave me, it mentions macrophages involved in antigen-presenting cells (B-cells/humoral response). You could probably mention phagocytes, but if the mark scheme/notes say macrophage, I'll put that. Up to you.

It is. One of the questions is 'Explain the shape of the curve between 20 and 60 minutes and 50 degrees' and the answer is

-denaturation/ alteration in tertiary structure
-breaking of bonds
-change in active site, substrate cannot bind

And if it wasn't denatured then why is less mass of product formed.
Silly.

What I want to know is why is it not denatured to start with? Does it take time to denature it.

ok...
an old paper, and the spec has changed since, you dont need to be that specific.

yes it does take time to denature the enzyme hence why it lows down slowly and doesn't abruptly stop

Or you can just do 10-5 then 5/5 x 100..

cause.

symptoms

reason for symptoms

Lol, what was so 'specific' about what I said? Macrophages are the phagocyte. I don't see why it's difficult to put macrophage as opposed to 'phagocyte', which is the correct type used, and more likely to give you the marks (depending on how specific the mark scheme is).

If one paper mentions 'describe how b cells are involved in humoral immunity', and then, a few years later, another paper asks the same question, what will the difference be? >_> Ugh, not gonna contine arguing with someone who's been neg repped as much as you, lol.

water potential

Or you can just do 10-5 then 5/5 x 100..

maybe, but i always do initial - final / initial x 100, if it works then go for it, but if a method works don't change it as they say.
the reason for this is that in these question you automatically get both marks if you get the correct percentage