VCE Biology Question Thread

[sunshine98]

But..

Spoiler

And yeeah, a ribozyme is defined as 'a RNA enzyme' so..

I remember asking my teacher about this, and he said that he was pretty sure in VCE bio u look at all enzymes as being  proteins.

[vox nihili]

In VCE we assume enzymes are proteins, but it's total crap. The first enzymes were RNAs and ribosomes, a massive fuck-off enzyme basically, are made of protein and RNA. Ignore the question, it's bad

[geminii]

In VCE we assume enzymes are proteins, but it's total crap. The first enzymes were RNAs and ribosomes, a massive fuck-off enzyme basically, are made of protein and RNA. Ignore the question, it's bad

Would there ever be a question asking for the definition of an enzyme? If so, what should we write?

[Sine]

Would there ever be a question asking for the definition of an enzyme? If so, what should we write?

for vce bio: A protein and biological catalyst which increases the rate of a chemical reaction (which would have otherwise have not occured fast enough to maintain life)
,
main pts: catalyst / increases rate of reaction

usually in bio the question would be along the lines of "what is the role of an enzyme?"

[geminii]

for vce bio: A protein and biological catalyst which increases the rate of a chemical reaction (which would have otherwise have not occured fast enough to maintain life)
,
main pts: catalyst / increases rate of reaction

usually in bio the question would be along the lines of "what is the role of an enzyme?"

Thanks, this is great

I have another question - apart from amino acids, are there any other molecules that, when bonded together, form a condensation reaction?
Also, I'm struggling to grasp the concept of the proteome - what is it? After looking at the timetable of what we'll be learning each week in class, I found out that we've already covered the proteome aspect. Since I still don't understand it, it would be awesome if someone could explain what it is, and all the details I'd need to know for the exam!

Thanks heaps

[sunshine98]

Also, apart from amino acids, are there any other molecules that, when bonded together, form a condensation reaction?

All biomacromolecules.
Monosaccharides undergo condensation to form a disaccharides and polysaccharides.
To form a triglyceride (as an example of a lipid) the glycerol molecule undergoes condensation with 3 fatty acid chains (with the loss this time of three water molecules)
Nucleotides also undergo condensation reactions to form polynucleotides (so a phosphate will react to deoxyribose sugar (DNA as an example) to form that phosphodiester bond that forms backbone of DNA  ) 

[Sine]

Thanks, this is great

I have another question - apart from amino acids, are there any other molecules that, when bonded together, form a condensation reaction?
Also, I'm struggling to grasp the concept of the proteome - what is it? After looking at the timetable of what we'll be learning each week in class, I found out that we've already covered the proteome aspect. Since I still don't understand it, it would be awesome if someone could explain what it is, and all the details I'd need to know for the exam!

Thanks heaps

condesation reaction is pretty much in bio: two monomers joining together and producing water. not only for amino acids but stuff like glucose monomers, nucleotides and lipids. Most importantly know that condensation is joining of monomers producing water.
Hydrolysis is using water to split monomers.
Also it could be something a carboxylic acid + alcohol ---> ester + water (chemistry 3/4)

Proteome = entire protein complement produced by the genome (meaning all the proteins which are produced after transcribing and translating all the genes)

Genome = the entire genetic component of an organism

All cells in an organism have the same genome. However cells on use certain genes.
This is a super tiny part of the course would usually be a recall multiple choice question.

[TheAspiringDoc]

Isn't there something about the proteome being more complex than the genome?

[vox nihili]

Isn't there something about the proteome being more complex than the genome?

Absolutely. The transcriptome (i.e. mRNA) is also more complex than the genome

[geminii]

How are both hydrolysis and the condensation reaction exergonic? I thought hydrolysis was endergonic (as it is using energy to break down polymers into monomers) while condensation reactions were exergonic (as it builds polymers from monomers)? Or have I got this completely wrong?
Thanks

[TheAspiringDoc]

How are both hydrolysis and the condensation reaction exergonic? I thought hydrolysis was endergonic (as it is using energy to break down polymers into monomers) while condensation reactions were exergonic (as it builds polymers from monomers)? Or have I got this completely wrong?
Thanks

Hydrolysis is exergonic as it is catabolic.
Condensation reactions are endergonic as they are anabolic
edit: check out condensation polymerisation

[geminii]

Hydrolysis is exergonic as it is catabolic.
Condensation reactions are endergonic as they are anabolic
edit: check out condensation polymerisation

Thanks for clearing this up! 

[TheAspiringDoc]

Why is it that plant cells don't lyse when placed into a hypotonic solution? Is it because their cell walls keep them together, or because the cell walls prevent the entry of too much water?

[geminii]

Why is it that plant cells don't lyse when placed into a hypotonic solution? Is it because their cell walls keep them together, or because the cell walls prevent the entry of too much water?

Unlike human cells (which prefer an isotonic solution), plant cells prefer to be turgid and hence like being placed in hypotonic solutions. The cell wall prevents it from ever bursting.

[TheAspiringDoc]

Unlike human cells (which prefer an isotonic solution), plant cells prefer to be turgid and hence like being placed in hypotonic solutions. The cell wall prevents it from ever bursting.

I know that, but what I'm asking is how the cell wall keeps it from bursting?