VCE Biology Question Thread

[Scooby]

Hi, I just did the enzyme liver prac today that involved placing fresh liver pieces in hydrogen peroxide and measuring the height of the bubbles present.

I was wondering, what are the bubbles that are produced?
Is it the water that is formed as a result of hydrogen peroxide being broken down into oxygen and water?

Thanks

Catalase converts hydrogen peroxide to water and oxygen. The bubbles are of oxygen gas

[millie96]

how does the induced fit model work to break down substrates?

[sammiegan]

Would it be correct to say that inhibitor molecules, stop enzyme activity altogether?

Or do they only decrease it?

Thanks!

[sarahsmiggle]

hi, um i did an enzyme prac the other day, and was wondering if anyone knew how to answer this question:

Humans produce two types of amylase, salivary amylase which acts in the mouth and pancreatic amylase which acts in the small intestine. Suggest one reason why it is necessary to produce the enzyme in both places.

thank you

[nerdmmb]

how does the induced fit model work to break down substrates?

In the induced fit model, the active site of an enzyme changes temporarily to fit the binding site of the substrate molecule/s with the aid of co-enzymes/co-factors. The induced fit model isn't only for the decomposition of substrates but also for the synthesis of other biomolecules. Once the substrate has been altered, the enzyme's active site returns to it's initial shape.

[alchemy]

Would it be correct to say that inhibitor molecules, stop enzyme activity altogether?

Or do they only decrease it?

Permanent inhibitors stop enzyme activity altogether. Temporary inhibitors slow down the reaction from occurring.

Humans produce two types of amylase, salivary amylase which acts in the mouth and pancreatic amylase which acts in the small intestine. Suggest one reason why it is necessary to produce the enzyme in both places.

All metabolic reactions in the body require enzymes to occur. Enzymes are substrate specific. Thus, an enzyme must be present at the place where there are complementary substrates for it, in order to catalyse the required reaction at that place.

[sarahsmiggle]

Permanent inhibitors stop enzyme activity altogether. Temporary inhibitors slow down the reaction from occurring.

All metabolic reactions in the body require enzymes to occur. Enzymes are substrate specific. Thus, an enzyme must be present at the place where there are complementary substrates for it, in order to catalyse the required reaction at that place.

thank you so much!

[bio12345]

http://www.gtac.edu.au/site/teacher_access/teacher_access_resources/Unit3-Study1-Outcome1/Task2-StudentWB_Unit3_O1_amylaseSAC.pdf

Hi we did a prac today which I've pasted above ^ . But I'm stuck on Q9, I'm hoping somebody could help me.
Q9 is:  A customer returned to the hardware store complaining that the DIF wallpaper stripper did not work and demanded a refund. During the discussion with the shop owner it was realised that the customer had originally used a new style of synthetic vinyl wall paper glue on his wall paper. Suggest one reason why DIF wall paper stripper did not work for the customer.

[alchemy]

http://www.gtac.edu.au/site/teacher_access/teacher_access_resources/Unit3-Study1-Outcome1/Task2-StudentWB_Unit3_O1_amylaseSAC.pdf

Hi we did a prac today which I've pasted above ^ . But I'm stuck on Q9, I'm hoping somebody could help me.
Q9 is:  A customer returned to the hardware store complaining that the DIF wallpaper stripper did not work and demanded a refund. During the discussion with the shop owner it was realised that the customer had originally used a new style of synthetic vinyl wall paper glue on his wall paper. Suggest one reason why DIF wall paper stripper did not work for the customer.

Sorry I haven't read all the details in that link, but the answer should be because the enzyme was unable to act on the new style of synthetic vinyl. Like I mentioned before, enzymes are substrate specific. So, the enzyme might not have been able to act on the substrate molecules on the synthetic vinyl wallpaper.

[Rishi97]

Sorry I haven't read all the details in that link, but the answer should be because the enzyme was unable to act on the new style of synthetic vinyl. Like I mentioned before, enzymes are substrate specific. So, the enzyme might not have been able to act on the substrate molecules on the synthetic vinyl wallpaper.

Ill try this too. The DIF wallpaper did not work because the amylase only breaks down starch and the new style of synthetic vinyl may not have contained starch. Thus, the amylase in the paint stripper had nothing to break down.

[sarahsmiggle]

hi, i also need help with this question too, i'm finding amylase really difficult to understand for some reason, or probably its just biology in general

Amylase is produced in germinating plant seeds so that starch can be used as an energy source. Use evidence from your experiment to suggest how seeds are able to germinate in both cold and warm climates.  (we tested amylase in both hot and cold temperatures, but i cannot understand how it relates to plant seeds)

many thanks hehe

[Tyleralp1]

Amylase is an enzyme which breaks down starch into glucose. Therefore, the amylase works on the energy stores of starch, breaking it down into glucose. This can then be used by the cell for cellular respiration to grow and develop. The growth may be different in different weather climates, due to the temperatures effecting the enzyme. Too hot =  no growth (enzyme denatures, hence can't bind to active site), warm = optimum conditions (best growth as enzymes work best), too cold = slow growth (enzyme becomes inactive due to less kinetic energy).

Hope that's it

[sarahsmiggle]

Amylase is an enzyme which breaks down starch into glucose. Therefore, the amylase works on the energy stores of starch, breaking it down into glucose. This can then be used by the cell for cellular respiration to grow and develop. The growth may be different in different weather climates, due to the temperatures effecting the enzyme. Too hot =  no growth (enzyme denatures, hence can't bind to active site), warm = optimum conditions (best growth as enzymes work best), too cold = slow growth (enzyme becomes inactive due to less kinetic energy).

Hope that's it

thank you!

[JadedBlack]

Wow, that wallpaper glue prac was part of our enzyme SAC. l didn't do too badly, ended up losing 1 mark for not stating the pH of the environments of salivary amylase and pancreatic amylase were different  and so affected the optimum pH at which each enzyme would work.

[millie96]

can somebody elaborate on how enzymes speed up chemical reactions? Like what happens with the chemical bonding etc