VCE Biology Question Thread

[howlingwisdom]

I'm a tad confused about enzyme activity/rate of reactions.

When you are increasing the substrate or enzyme concentration, does this mean you are generating more product or just decreasing the time it takes to get to a certain amount of product?

[alchemy]

I'm a tad confused about enzyme activity/rate of reactions.

When you are increasing the substrate or enzyme concentration, does this mean you are generating more product or just decreasing the time it takes to get to a certain amount of product?

Very important question. Enzymes do not affect the equilibrium of a reaction. That means more product isn't prouduced in an enzyme catalysed reaction. All enzymes do, by increasing the rate of the reaction, reduce the time required to yield a certain amount of product.

[katie101]

The ‘white’ of a hen's egg is the protein albumin, which changes from a clear jelly-like substance to solid white matter when it is cooked. The protein has been irreversibly denatured. Sometimes denaturation of a protein is reversible.

Examine the illustration below. Protein X was denatured as its sulfide bonds broke when the molecule was exposed to a particular chemical. However, when the chemical was removed, protein X reformed its original tertiary structure. Explain whether you think that, after such treatment, protein X would still be able to perform its original function.

Image Attached

Thanks, as I'm a little confused

[vox nihili]

The ‘white’ of a hen's egg is the protein albumin, which changes from a clear jelly-like substance to solid white matter when it is cooked. The protein has been irreversibly denatured. Sometimes denaturation of a protein is reversible.

Examine the illustration below. Protein X was denatured as its sulfide bonds broke when the molecule was exposed to a particular chemical. However, when the chemical was removed, protein X reformed its original tertiary structure. Explain whether you think that, after such treatment, protein X would still be able to perform its original function.

Image Attached

Thanks, as I'm a little confused

It has the same conformation as the original protein, so of course. That's all that matters. Is the protein in the same shape again? Yep. Any inhibitors? Nope. Does it work? Yep! Shape determines function of an eznyme

[kx4y]

Can someone please explain to me what happens to the reaction rate when there is:
- unlimited enzymes
- limited enzymes
- unlimited substrates
- limited substrates?

 

[katie101]

Can the Calvin cycle can occur only in the dark?

[slothpomba]

Can someone please explain to me what happens to the reaction rate when there is:
- unlimited enzymes
- limited enzymes
- unlimited substrates
- limited substrates?

 

Care to try these first? As for the plant one, sorry, got no idea about plants.

[Rishi97]

Are endothermic reactions and endergonic reactions the same as an anabolic reaction?

[slothpomba]

Are endothermic reactions and endergonic reactions the same as an anabolic reaction?

First two are chemistry terms, last one is a biology term. That's why there is a duplication. "Anabolism (from Greek: ανά "upward" and βάλλειν "to throw") is the set of metabolic pathways that construct molecules from smaller units.[1] These reactions require energy. " Which one of those two chemistry terms refer to reactions which require an input of energy? Figure that ou9t and you'll have your answer.

[Rishi97]

First two are chemistry terms, last one is a biology term. That's why there is a duplication. "Anabolism (from Greek: ανά "upward" and βάλλειν "to throw") is the set of metabolic pathways that construct molecules from smaller units.[1] These reactions require energy. " Which one of those two chemistry terms refer to reactions which require an input of energy? Figure that ou9t and you'll have your answer.

Is it endergonic?

[RazzMeTazz]

In my Biology book it says that coenzymes are small cofactor molecules and my biology teacher said that you can classify coenzymes as cofactors, but then my biology book says cofactors are "small inorganic substances" and coenzymes are "small organic non-protein molecules"

How can coenzymes be organic, if they are considered to be a type of cofactor, when cofactors are inorganic?

o.O

[grannysmith]

Is it endergonic?

Yes

[nhmn0301]

In my Biology book it says that coenzymes are small cofactor molecules and my biology teacher said that you can classify coenzymes as cofactors, but then my biology book says cofactors are "small inorganic substances" and coenzymes are "small organic non-protein molecules"

How can coenzymes be organic, if they are considered to be a type of cofactor, when cofactors are inorganic?

o.O

Cofactors include BOTH inorganic and organic particles. The difference between these 2 is that the inorganic particles are not changed during the reaction whilst organic particles (which include coenzymes) are altered.

[grannysmith]

In my Biology book it says that coenzymes are small cofactor molecules and my biology teacher said that you can classify coenzymes as cofactors, but then my biology book says cofactors are "small inorganic substances" and coenzymes are "small organic non-protein molecules"

How can coenzymes be organic, if they are considered to be a type of cofactor, when cofactors are inorganic?

o.O

The term cofactor is a collective term encompassing both organic and inorganic non-protein substances which are necessary for particular enzymes to function. However, coenzymes specifically refer to organic molecules (e.g. vitamins)
Edit: beaten

[MagicGecko]

Can the Calvin cycle can occur only in the dark?

Nope that would mean that plants only have 'dinner'
But yeah, the Calvin cycle can also occur in broad daylight, the only reason why it is called the 'dark-reaction' is because unlike the 'light-reaction', the Calvin cycle does not need an input of sunlight.