Exam Discussion

[ILiekMudkipz]

Isn't meat in proteins like tertiary structure? And polypeptides the broken down primary structure? I understand the reasoning about polypeptides being proteins but why would 37 show such high levels? Its like 37 doesn't breakdown proteins? I just figured breakdown to amino acids happens in the intestines

yeah that's true, 37 should have been really low then :S

You have nothing to compare it to, how do you know its not already low? =/

True but it said the results were after 10 hours. After 10 hours would there be any material that hasn't broken down? I think if the explanations are correct either a higher or lower response can be accepted

This wasn't one of those do you agree or disagree type of questions lol.
It's either right or wrong, if the enzymes have denatured then there must be a higher amount of polypeptides, it can't be lower because that would mean the ezymes are functioning better

[ILiekMudkipz]

For the 1st SA question. It had an electron micrograph like this http://umanitoba.ca/Biology/BIOL1020/lab3/images/PlantCell-Micrograph1.jpg - It asked for structure X, I wrote cell wall because it was relatively thick in comparison to the large mitochondrion? But EVERYONE else chose cell membrane..... they said they didn't see any chloroplasts....but it doesn't have to have chloroplasts to be a plant cell like the root cells that are plant cells despite having no chloroplasts? UGH, am i being a smart cookie or naive student? I hope it's the first 

Wouldn't there be a double layer since there would be a cell wall and membrane?

[ChickenCh0wM1en]

Just to be clear for myself and pretty much everyone else, is this correct?
https://www.dropbox.com/s/ponyhudjkpbk3ms/Polypeptide.png

thats what I did, but apparently its wrong

[alphamale]

yes pig was correct,

someone tell me something to feel better lool (realizing the marks lost) rofls.

yeah everytime I talk to someone about the exam, I realise a lose a mark

If i talked to 75 different people...well....

[Edward21]

For the 1st SA question. It had an electron micrograph like this http://umanitoba.ca/Biology/BIOL1020/lab3/images/PlantCell-Micrograph1.jpg - It asked for structure X, I wrote cell wall because it was relatively thick in comparison to the large mitochondrion? But EVERYONE else chose cell membrane..... they said they didn't see any chloroplasts....but it doesn't have to have chloroplasts to be a plant cell like the root cells that are plant cells despite having no chloroplasts? UGH, am i being a smart cookie or naive student? I hope it's the first 

Wouldn't there be a double layer since there would be a cell wall and membrane?

But the cell membrane is mainly a phospholipid bilayer....they're tiny!? UGH I don't know  when Connect Education puts out it suggested answers....maybe then we'll know?

[G-lain]

This is my first post here, so hello all
For the protein levels one, it's a bit confusing, and I'm sure I got it wrong. But you have to consider that at 80 degrees, most of the proteins (polypeptides) would have denatured thus breaking the peptide bonds, meaning there would be a lower overall concentration of polypeptides and a higher concentration of independent amino acids.
For the 10 degrees one, I put the same concentration as the 35 degrees because I don't remember reading anything about enzymes, however I did only briefly skim over the question. I would assume though that if there were enzymes in the solution, at 35 degrees they would of broken down the proteins, all though this could still result in there being a high concentration of polypeptides.
However I'm not sure so I'm assuming I lost all of the marks :|

[ChickenCh0wM1en]

This is my first post here, so hello all
For the protein levels one, it's a bit confusing, and I'm sure I got it wrong. But you have to consider that at 80 degrees, most of the proteins (polypeptides) would have denatured thus breaking the peptide bonds, meaning there would be a lower overall concentration of polypeptides and a higher concentration of independent amino acids.
For the 10 degrees one, I put the same concentration as the 35 degrees because I don't remember reading anything about enzymes, however I did only briefly skim over the question. I would assume though that if there were enzymes in the solution, at 35 degrees they would of broken down the proteins, all though this could still result in there being a high concentration of polypeptides.
However I'm not sure so I'm assuming I lost all of the marks :|

I essentially did the same thing, because I interpreted it differently and thought they extracted the protein (polypeptide) purely from the "protein-rich" food the dude ate.

[nonimous]

Isn't meat in proteins like tertiary structure? And polypeptides the broken down primary structure? I understand the reasoning about polypeptides being proteins but why would 37 show such high levels? Its like 37 doesn't breakdown proteins? I just figured breakdown to amino acids happens in the intestines

yeah that's true, 37 should have been really low then :S

You have nothing to compare it to, how do you know its not already low? =/

True but it said the results were after 10 hours. After 10 hours would there be any material that hasn't broken down? I think if the explanations are correct either a higher or lower response can be accepted

This wasn't one of those do you agree or disagree type of questions lol.
It's either right or wrong, if the enzymes have denatured then there must be a higher amount of polypeptides, it can't be lower because that would mean the ezymes are functioning better

Yeah but I understood that it was proteins (tertiary structure) being broken down to polypeptides (primary structure). If it was polypeptides to amino acids wouldnt the polypeptide conc at 37 be zero? Afterall 37 should be optimum enzyme level?

[peterle]

Very first post for me too!

For this question, I assumed that we had to deduce that there are already enzymes (peptidases) present in the stomach, from which the experiment contents were collected and incubated at the different temperatures (10 degrees and 80 degrees). In saying this, the solution which was incubated at 10 degrees would have meant that the enzymes of the stomach and the protein molecules from the protein-rich food were moving slowly and would cause fewer collisions between enzyme and substrate to occur. Hence, the protein molecules from the food would be broken down into polypeptides at a slower rate, resulting in a lower polypeptide concentration than that of 37 degrees. And as for the solution incubated at 80 degrees, the enzymes that would work to break down the protein into polypeptides would have denatured due to the extremely high temperature above the optimum, and hence the polypeptide concentration would be 0 or very close to 0.

Sorry for the lengthy reply but this is how I interpreted the question - please correct me if I'm wrong!

This is my first post here, so hello all
For the protein levels one, it's a bit confusing, and I'm sure I got it wrong. But you have to consider that at 80 degrees, most of the proteins (polypeptides) would have denatured thus breaking the peptide bonds, meaning there would be a lower overall concentration of polypeptides and a higher concentration of independent amino acids.
For the 10 degrees one, I put the same concentration as the 35 degrees because I don't remember reading anything about enzymes, however I did only briefly skim over the question. I would assume though that if there were enzymes in the solution, at 35 degrees they would of broken down the proteins, all though this could still result in there being a high concentration of polypeptides.
However I'm not sure so I'm assuming I lost all of the marks :|

[nonimous]

Very first post for me too!

For this question, I assumed that we had to deduce that there are already enzymes (peptidases) present in the stomach, from which the experiment contents were collected and incubated at the different temperatures (10 degrees and 80 degrees). In saying this, the solution which was incubated at 10 degrees would have meant that the enzymes of the stomach and the protein molecules from the protein-rich food were moving slowly and would cause fewer collisions between enzyme and substrate to occur. Hence, the protein molecules from the food would be broken down into polypeptides at a slower rate, resulting in a lower polypeptide concentration than that of 37 degrees. And as for the solution incubated at 80 degrees, the enzymes that would work to break down the protein into polypeptides would have denatured due to the extremely high temperature above the optimum, and hence the polypeptide concentration would be 0 or very close to 0.

Sorry for the lengthy reply but this is how I interpreted the question - please correct me if I'm wrong!

This is my first post here, so hello all
For the protein levels one, it's a bit confusing, and I'm sure I got it wrong. But you have to consider that at 80 degrees, most of the proteins (polypeptides) would have denatured thus breaking the peptide bonds, meaning there would be a lower overall concentration of polypeptides and a higher concentration of independent amino acids.
For the 10 degrees one, I put the same concentration as the 35 degrees because I don't remember reading anything about enzymes, however I did only briefly skim over the question. I would assume though that if there were enzymes in the solution, at 35 degrees they would of broken down the proteins, all though this could still result in there being a high concentration of polypeptides.
However I'm not sure so I'm assuming I lost all of the marks :|

Very good explanation!! That's exactly my train of thought

[G-lain]

Very first post for me too!

For this question, I assumed that we had to deduce that there are already enzymes (peptidases) present in the stomach, from which the experiment contents were collected and incubated at the different temperatures (10 degrees and 80 degrees). In saying this, the solution which was incubated at 10 degrees would have meant that the enzymes of the stomach and the protein molecules from the protein-rich food were moving slowly and would cause fewer collisions between enzyme and substrate to occur. Hence, the protein molecules from the food would be broken down into polypeptides at a slower rate, resulting in a lower polypeptide concentration than that of 37 degrees. And as for the solution incubated at 80 degrees, the enzymes that would work to break down the protein into polypeptides would have denatured due to the extremely high temperature above the optimum, and hence the polypeptide concentration would be 0 or very close to 0.

Sorry for the lengthy reply but this is how I interpreted the question - please correct me if I'm wrong!

There is essentially little difference between a protein and a polypeptide, although most proteins consist of multiple polypeptides, e.g. haemoglobin, there are proteins made from just one polypeptide e.g. the enzyme lysozyme.
I'm sure we were meant to talk about enzymes, as I said I didn't thoroughly read over the question so I didn't actually realise the solutions were obtained from a man's stomach (poor bastard). That said still, I think the concentration of polypeptides would of been less at 80 degrees because the peptide bonds probably would of broken resulting in just amino acids.
For the 10 degrees one, I think it really depends on whether there were enzymes or not, I'm sure it's safe to assume there were enzymes.

[peterle]

Yeah, I was thinking that when I was reading the question too! But I remembered a multiple choice question on the 2009 VCAA exam, where a diagram showed that proteins were being broken down into polypeptides and just went with my explanation.

There is essentially little difference between a protein and a polypeptide, although most proteins consist of multiple polypeptides, e.g. haemoglobin, there are proteins made from just one polypeptide e.g. the enzyme lysozyme.

[amilss]

For this question, I assumed that we had to deduce that there are already enzymes (peptidases) present in the stomach, from which the experiment contents were collected and incubated at the different temperatures (10 degrees and 80 degrees). In saying this, the solution which was incubated at 10 degrees would have meant that the enzymes of the stomach and the protein molecules from the protein-rich food were moving slowly and would cause fewer collisions between enzyme and substrate to occur. Hence, the protein molecules from the food would be broken down into polypeptides at a slower rate, resulting in a lower polypeptide concentration than that of 37 degrees. And as for the solution incubated at 80 degrees, the enzymes that would work to break down the protein into polypeptides would have denatured due to the extremely high temperature above the optimum, and hence the polypeptide concentration would be 0 or very close to 0.


Sorry for the lengthy reply but this is how I interpreted the question - please correct me if I'm wrong!

That was how i interpreted the question as well. I hope it's right!

[ligands]

do you think they accept a lot of answers for the polypeptide question seems it could be interrupted differently?

[InsaneMcFries]

In the alternate interpretation of the polypeptide graph, would it also make sense to say that the enzymes themselves are polypeptides?