Exam Discussion

[ligands]

for the rod cell one i just said the stimulus is not being opposed in this feedback system, therefore this system cannot be negative feed

[InsaneMcFries]

I thought 80degrees was to week to break covalent bonds(peptide bonds) and would only disrupt the bonds maintaing the shape of tertiary and secondary stucture

I'm fairly sure this isn't what they were after, I think they wanted you to think about the fact that there are enzymes in the stomach acid.

[LOLs99]

what did u guys put for MC Q24? I think I put D or A.
This exam is easy but tricky! Thank god there is no experimental design.

[itsdanny]

Was the process positive or negative feedback?!

the 'rod cell' thing? lol i said it wasn't negative feedback

Yep, I said the same. Only because it does have to work in a positive feedback state, otherwise, we wouldn't be able to see in the dark! It is only when your eyes are exposed to a flash of light (like driving at night and someone comes around the corner with their high-beams), the rod cells (not cones cells, as these are not involved), which are very light-sensitive, make use of at least three negative feedback mechanisms (inhibitory) to allow a prompt recover back to the resting state.

[G-lain]

It wasn't negative feedback, it was just stimulus-response as the response did not act to reverse the stimulus which was light.

If the electric signal resulted in the eye moving away from the light, wouldn't that be negative feedback as the response moved the rod cell away from the light?
I put both and justified them both, if the result of the light being detected moves the eye away from the light then yes, if it doesn't result in that then it isn't as there is no action on the stimulus.

[MisterTransistor]

for the rod cell one i just said the stimulus is not being opposed in this feedback system, therefore this system cannot be negative feed

I think it was signal transduction as it involved cGMP, although I don't think you needed to mention any of this at all as long as you described that it isn't negative feedback. I wrote the same thing as you.

what did u guys put for MC Q24? I think I put D or A.

I chose the one that said the antigens had a complementary shape to the antibody? Is that what you put?

[ligands]

for the rod cell one i just said the stimulus is not being opposed in this feedback system, therefore this system cannot be negative feed

I think it was signal transduction as it involved cGMP, although I don't think you needed to mention any of this at all as long as you described that it isn't negative feedback. I wrote the same thing as you.

what did u guys put for MC Q24? I think I put D or A.

I chose the one that said the antigens had a complementary shape to the antibody? Is that what you put?

i said the same as you, the antigens had complementary shape to the anibody

[kensan]

what did u guys put for MC Q24? I think I put D or A.
This exam is easy but tricky! Thank god there is no experimental design.

Yeah I put D, was considering A after eliminating B and C. changed last moment lol

[ligands]

what did u guys put for MC Q24? I think I put D or A.
This exam is easy but tricky! Thank god there is no experimental design.

Yeah I put D, was considering A after eliminating B and C. changed last moment lol

was D the antigen has the complementary shop to the antibody?

[kensan]

what did u guys put for MC Q24? I think I put D or A.
This exam is easy but tricky! Thank god there is no experimental design.

Yeah I put D, was considering A after eliminating B and C. changed last moment lol

was D the antigen has the complementary shop to the antibody?

yeah it was

[thushan]

Couldn't see properly whether this was already explained but here's my thoughts on the polypeptide qn:

Did they ask for the relative amount of polypeptide (which would have been a substrate for a protease enzyme in the stomach - that's what I inferred from what you guys are talking about) for each temperature? I havent seen the exam paper yet.

At 10 degrees, the proteases are working but slowly. So the amount of polypeptide would be relatively high (because only some of the polypeptide has been broken down).

At 37 degrees, the proteases are probs working at optimum level. So the amount of polypeptide would be low (because most of the polypeptide has been broken down).

At 80 degrees, the proteases are denatured and do not work [80 degrees does not break COVALENT bonds, it breaks hydrogen bonds], so cannot convert polypepeptide substrate into its amino acids. So the amount of polypeptide would be higher than that in 10 degrees (as none of it has been broken down).

Was that what the question was asking?

[MisterTransistor]

Couldn't see properly whether this was already explained but here's my thoughts on the polypeptide qn:

Did they ask for the relative amount of polypeptide (which would have been a substrate for a protease enzyme in the stomach - that's what I inferred from what you guys are talking about) for each temperature? I havent seen the exam paper yet.

At 10 degrees, the proteases are working but slowly. So the amount of polypeptide would be relatively high (because only some of the polypeptide has been broken down).

At 37 degrees, the proteases are probs working at optimum level. So the amount of polypeptide would be low (because most of the polypeptide has been broken down).

At 80 degrees, the proteases are denatured and do not work [80 degrees does not break COVALENT bonds, it breaks hydrogen bonds], so cannot convert polypepeptide substrate into its amino acids. So the amount of polypeptide would be higher than that in 10 degrees (as none of it has been broken down).

Was that what the question was asking?

Pretty much Except I think you had to infer that proteases were present in the stomach. (I can't remember whether they gave you this information.)

[Gazillionaire]

Couldn't see properly whether this was already explained but here's my thoughts on the polypeptide qn:

Did they ask for the relative amount of polypeptide (which would have been a substrate for a protease enzyme in the stomach - that's what I inferred from what you guys are talking about) for each temperature? I havent seen the exam paper yet.

At 10 degrees, the proteases are working but slowly. So the amount of polypeptide would be relatively high (because only some of the polypeptide has been broken down).

At 37 degrees, the proteases are probs working at optimum level. So the amount of polypeptide would be low (because most of the polypeptide has been broken down).

At 80 degrees, the proteases are denatured and do not work [80 degrees does not break COVALENT bonds, it breaks hydrogen bonds], so cannot convert polypepeptide substrate into its amino acids. So the amount of polypeptide would be higher than that in 10 degrees (as none of it has been broken down).

Was that what the question was asking?

Yeah that's what it was asking.

[G-lain]

Couldn't see properly whether this was already explained but here's my thoughts on the polypeptide qn:

Did they ask for the relative amount of polypeptide (which would have been a substrate for a protease enzyme in the stomach - that's what I inferred from what you guys are talking about) for each temperature? I havent seen the exam paper yet.

At 10 degrees, the proteases are working but slowly. So the amount of polypeptide would be relatively high (because only some of the polypeptide has been broken down).

At 37 degrees, the proteases are probs working at optimum level. So the amount of polypeptide would be low (because most of the polypeptide has been broken down).

At 80 degrees, the proteases are denatured and do not work [80 degrees does not break COVALENT bonds, it breaks hydrogen bonds], so cannot convert polypepeptide substrate into its amino acids. So the amount of polypeptide would be higher than that in 10 degrees (as none of it has been broken down).

Was that what the question was asking?

Well I'm screwed for that one then..

[nonimous]

Couldn't see properly whether this was already explained but here's my thoughts on the polypeptide qn:

Did they ask for the relative amount of polypeptide (which would have been a substrate for a protease enzyme in the stomach - that's what I inferred from what you guys are talking about) for each temperature? I havent seen the exam paper yet.

At 10 degrees, the proteases are working but slowly. So the amount of polypeptide would be relatively high (because only some of the polypeptide has been broken down).

At 37 degrees, the proteases are probs working at optimum level. So the amount of polypeptide would be low (because most of the polypeptide has been broken down).

At 80 degrees, the proteases are denatured and do not work [80 degrees does not break COVALENT bonds, it breaks hydrogen bonds], so cannot convert polypepeptide substrate into its amino acids. So the amount of polypeptide would be higher than that in 10 degrees (as none of it has been broken down).

Was that what the question was asking?

That was one interpretation. My one was the heated discussion earlier haha about proteins being broken down into polypeptides. Though I think your reasoning makes sense too