VCE Biology Question Thread

[cosine]

Hellloooo, going to try my best to answer your questions hahah

What is the site on an enzyme that a non-competitive inhibitor binds to?
any site other than the active site

Also, some enzymes are not primarily composed of proteins, right? For example, an enzyme could be inactive until a cofactor binds to it, so the enzyme is essentially composed of a protein part, and a non-organic non-protein part. So could you call the protein part the enzyme, or is the 'whole' structure (by this I mean including the cofactor) called the enzyme?
apoenzyme = protein portion.  you probably don't need to know this but apoenzyme + coenzyme = holoenzyme
Oh and when a non-competitive inhibitor binds to the enzyme, it will deform the shape of the enzyme and consequently break the R-group/variable interractions. What is the proper term instead of 'break' the interractions?
I'm not sure, but I think you only need to know that it changes the active site.

Last question, promise. When the temperature is decreased in an enzyme-catalysed reaction, does it reduce the molecular kinetic movement of the substrate and enzyme, henceforth reducing the opportunity for the subtrate to bind to the cleft of the enzyme? If so, what about enzyme's whose optimum temperature is really low, does this mean that the molecular movements are still slow, but does this mean that the enzymatic activity is generally slow or is this beyond the scope of VCE biology?
yes, hmm i don't know an enzyme which has a very low optimum temperature... but ALL molecules move slower at lower temperatures
Also, when an enzyme is exposed to it's optimum conditions/environments, does it perform at it's optimal ability? Is that the correct term?
I believe so.

you sound a little stressed, i don't think you need to worry about such technicalities and terms

Thanks vceva, im not stressed, haha

How exactly is respiration an oxidation reaction? Is it because we breathe in oxygen but release carbon dioxide, we are consuming oxygen - definition of oxidation: the addition of oxygen to an organic compound - is that the reason? If so, then what is reduction? o.O

[supergi]

Hi AN,

Can sand have the effect of increasing reaction rate of catalysing hydrogen peroxide into products O2 gas and H2O.
If so, if sand were to be placed in a solution of hydrogen peroxide and liver OR sand were to be grinded together with liver with a pestle and mortar before displacement in hydrogen peroxide OR sand were to be placed in a solution of hydrogen peroxide and a boiled liver sample, how would SAND effect these reactions?

Thanks in advance

[grannysmith]

Hi AN,

Can sand have the effect of increasing reaction rate of catalysing hydrogen peroxide into products O2 gas and H2O.
If so, if sand were to be placed in a solution of hydrogen peroxide and liver OR sand were to be grinded together with liver with a pestle and mortar before displacement in hydrogen peroxide OR sand were to be placed in a solution of hydrogen peroxide and a boiled liver sample, how would SAND effect these reactions?

Thanks in advance

The sand is just there as an abrasive, really. It helps grind the liver.

[scarletmoon]

Thanks vceva, im not stressed, haha

How exactly is respiration an oxidation reaction? Is it because we breathe in oxygen but release carbon dioxide, we are consuming oxygen - definition of oxidation: the addition of oxygen to an organic compound - is that the reason? If so, then what is reduction? o.O

I did 3/4 biology last year and you definitely don't need to know about oxidation and reduction, that's chemistry. its not even in the study design. Just know the reactants and products of respiration

[Sine]

What are typical Sac questions for the enzyme experiment with liver catalase. We tested it by boiling it, changing pH and grinding with sand.

[cosine]

Can someone explain the metabolic pathway in our bodies in simple terms please, having troubles understanding what exactly uses ATP, and what produces it? Thanks

[sunshine98]

Can someone explain the metabolic pathway in our bodies in simple terms please, having troubles understanding what exactly uses ATP, and what produces it? Thanks

Do you mean anabolism and catabolism? anabolism and catabolism make metabolism.
Anabolism is simply the building of larger molecules from smaller one , remember condensation polymerisation of organic molecules that is anabolism. Because you are making larger molecules , you need bonds between the smaller ones to make the larger ones , so you need ATP. Thus anabolic reactions , require energy or ATP , they are endergonic reactions.
Whereas, catabolic reactions are reactions involving the breaking of large molecules into smaller ones (like in hydrolysis). When you are breaking molecules, energy is released , thus ATP is released/produced  , because energy is released this is called an exergonic reaction. 
I hope I didn't misunderstand your  question, and that this was helpful   

[Jay.C]

Hey guys two questions. 
1. What is the relation of light intensity to carbon use during photosynthesis? Would that be carbon use would rise as light intensity gets stronger?
2. What is the interrelationship between photosynthesis and respiration?

[Sine]

Why is Distilled water & hydrogen peroxide tested as a control when the experiment is testing catalase(liver) activity with hydrogen peroxide?

[cosine]

Pros:

Is it plausible to lose marks in SACs to get ~50 in bio? Or even if i drop a few here and there, it is ultimately the exam to determine my score? Thanks

[faso]

Why is Distilled water & hydrogen peroxide tested as a control when the experiment is testing catalase(liver) activity with hydrogen peroxide?

Control is used as a comparison with the test to see the effect of the in-dependant variable on the dependant variable.
In this case we are testing the rate of reaction and enzyme would have on a reaction that would already occur naturally.  So when we put an enzyme in we can compare it to where there is no enzymes present. I hope you understand even though i could have explained it better.

[faso]

Pros:

Is it plausible to lose marks in SACs to get ~50 in bio? Or even if i drop a few here and there, it is ultimately the exam to determine my score? Thanks

Had A friend get 49 in bio sac average was  ~98% and dropped at least 2 marks on the exam. Im guessing if he aced it he would of got 50.

[Sine]

Control is used as a comparison with the test to see the effect of the in-dependant variable on the dependant variable.
In this case we are testing the rate of reaction and enzyme would have on a reaction that would already occur naturally.  So when we put an enzyme in we can compare it to where there is no enzymes present. I hope you understand even though i could have explained it better.

I forget to mention we boiled the enzyme in distilled water, does this change your answer? Thanks for the quick reply and great explanation.

[faso]

I forget to mention we boiled the enzyme in distilled water, does this change your answer? Thanks for the quick reply and great explanation.

You put enzymes in different water temperatures right?
If so Independent variable is temperature of enzyme and dependant is the rate of reaction.

Here is a definition of Control:
In one set up called the control(its really a comparison set up), all variables are kept constant(controlled) while the in the other set up one factor(temperature in your case) is varied.

Control is really just something we can compare to really.

[faso]

I forget to mention we boiled the enzyme in distilled water, does this change your answer? Thanks for the quick reply and great explanation.

And your welcome mate this really helped concrete what i was studying this week. So thank you for asking. I encourage everyone to ask questions so this way not only the person asking the question gets help but the person answering can use it as revision.