Random Chem questions.

[Hutchoo]

Are we supposed to know the structual isomers for gluclose? i.e  Fructose/galactose.
Do we have to be able to write equations based on those two monosaccherides [Fructose/galactose] ?

[pi]

Nope, don't memorise them. Maybe know that fructose in particular looks quite different and that it's found in plants. For galactose, similar structure to glucose and it's found in random stuff (dairy products, certain gums etc.).

As for equations, yes. But seeing as though all three of them have the same molecular formula (C6H12O6) it shouldn't be an issue

[Hutchoo]

Haha, I meant like drawing equations XD?

[Lasercookie]

If you want the structures of Glucose and Fructose, derive them from the Sucrose given in the data booklet (hydrolysis of sucrose will give these two). For Galactose, just remember the difference between Glucose and Galactose (the OH's and H's on the left and right are flipped - take a look at the diagrams of them).

[pi]

Haha, I meant like drawing equations XD?

Nah, not all three. Only for glucose as it's the only one in the data book (I think). The reactions you'd get might be respiration or something like the formation of a disaccharide.

[charmanderp]

If you want the structures of Glucose and Fructose, derive them from the Sucrose given in the data booklet (hydrolysis of sucrose will give these two). For Galactose, just remember the difference between Glucose and Galactose (the OH's and H's on the left and right are flipped - take a look at the diagrams of them).

With regards to Galactose, it's the OH and H on the fourth carbon of glucose which are flipped, to be specific.

[Hutchoo]

Just did a prac exam (2010 TSFX -- really shit exam tbh, wouldn't bother doing it//waste of time) and I'm looking at the suggested solutions and I'm confused with one of their explanations.

They say that m(ester) = m(acid) + m(carboxylic acid) - m(water)..
Shouldn't it be m(ester) = m(alcohol) + m(carboxylic acid) - m(water).. ??

[jadams]

yeah it's just a typo man.

[Hutchoo]

Are we supposed to remember complex molecules molecular mass/formula (e.g. styrene) off by heart?!

[pi]

Are we supposed to remember complex molecules molecular mass/formula (e.g. styrene) off by heart?!

Nah

[Hutchoo]

How about salicylic acid?

[pi]

How about salicylic acid?

Worth knowing that one. More the structure rather than the molecular formula though

[Aurelian]

Worth knowing that one. More the structure rather than the molecular formula though

I'd throw in the structure too for good measure - it's not particularly complicated. Just remember the IUPAC name and it's sawheet; 2-hydroxybenzoic acid

[Hutchoo]

Ty guys ! I'll remember it.

[Hutchoo]

Question 20
Correct functioning of an enzyme is dependent on its three-dimensional structure. If this
structure is disrupted the protein will denature.
Which of the following changes could result in denaturation?
I  The addition of a strong base.
II An increase in temperature.
III A decrease in temperature.
 
A. I only
B. II and III only
C. I and II only
D.  I, II and III


Can someone please go through how I and III will effect the enzyme?
Another bunch of random questions regarding this:

If a enzyme is decreasing in temperature, does it mean that it will go "slower" and will be unable to function properly/at all?

Can an enzyme "freeze' completely and be regarded as denatured? If a enzyme is in a frozen state, when put in a proper environment (tempreture/pH wise etc), will it maintain its original shape? Does denaturing only occur when the temperature rises?


Thank you very much:D