VCE Biology Question Thread

[Erutepa]

Hi
I am having trouble answering the question:
"Explain how the internal structure of chloroplasts helps absorb the maximum amount of light"
Is it because the thylakoid are stacked in grana, so that increases the surface area to absorb light?

You are on the right track, but you would want to make sure you state that chloroplasts have internal structure consisting of many thin thylakoid disks stacked in grana as to maximise the internal SA. Since light is absorbed by these surfaces, by having a greater surface area the internal structure of the chloroplast maximises light absorbance.

[maheenkhan]

Hello!

For fermentation (both ethanol and lactic acid fermentation), I was wondering if NAD is considered as an input and if NADH is considered as an output. Because NADH is regenerated into NAD and isn't actually released as an output.

Thank you.

[Erutepa]

Hello!

For fermentation (both ethanol and lactic acid fermentation), I was wondering if NAD is considered as an input and if NADH is considered as an output. Because NADH is regenerated into NAD and isn't actually released as an output.

Thank you.

Since there is not net consumption or production of NAD or NADH, I would not write them as outputs or inputs.

[f0od]

Hey!

Are grana and granum considered the same thing? (A stack of thylakoids)

Thanks

[PhoenixxFire]

Hey!

Are grana and granum considered the same thing? (A stack of thylakoids)

Thanks

Pretty much.
Granum is the singular form, grana is plural

[Jimmonash1991]

G'day,

I have a student whom is sitting her second outcome for Biology 3 and 4, and this has to do with signal transduction, neurotransmission, apoptosis, necrosis, and signalling molecules.

I am curious, since she doesn't know herself, whether this could be tested as some form of experiment, or whether this is usually a written test? My student already had an experiment for her first outcome.

The description of the "Biological Understanding and Application" is:

- Use your understanding of theory to apply to different scenarios (would suggest perhaps a text describing a situation, such as an insult to homeostasis, and predict response e.g. hormone, and how signal transduction pathway works)

- interpret, transpose, and communicate information and ideas effectively (suggests written responses to questions, but also could be write up for an experiment)

- use scientific terminology and conventions properly (which is a given for biology, whether in an exam or writing a report)

- analyse and interpret data (would suggest looking at a glucose response curve, or perhaps a nerve impulse curve)

Thanks for the help in advance,

Jim

[PhoenixxFire]

From the bio study design, the assessment can be:
•   a report of a practical activity
•   annotations of activities or investigations from
a logbook of practical activities
•   a graphic organiser
•   a bioinformatics exercise
•   an evaluation of research
•   media response
•   data analysis
•   a response to a set of structured questions
•   problem solving involving biological concepts,
skills and/or issues
•   a reflective learning journal/blog related to selected
activities or in response to an issue

So it could be an experiment, but I doubt it would be. It's normally just structured questions.

[Rameen]

Should ATP be written in the word and chemical equation of cellular respiration?

[darkz]

-

Well one experiment I can think of would be testing the effect of plant hormones (Yes, although the emphasis on plant hormones has decreased dramatically, some schools still go to the depth of teaching each hormone and conducting experiments on them/ asking questions on their SACs). Or since the experiments that can be conducted are quite limited, you could be given an experiment to evaluate. e.g. provided that they are given enough background information, they could be asked to evaluate a diabetes test etc.

Should ATP be written in the word and chemical equation of cellular respiration?

Yes, personally I would write it just for thoroughness.

[f0od]

Hey,

I have this question on a worksheet (q11 - attached) that I don't really understand. I'm unsure how you could measure a change in oxygen from adding in either glucose or pyruvate to one of the experiments, and I'm even more unsure of why there would be a change in oxygen concentration. E.g If glucose is added to a reaction tube with the cytosol of cells, do the oxygen levels decrease or stay the same as glucose cannot break down after glycolysis?

I have an answer from me attempting to figure out the question, but it's probably wrong

Any help would be greatly appreciated, thank you so much!

[PhoenixxFire]

Hey,

I have this question on a worksheet (q11 - attached) that I don't really understand. I'm unsure how you could measure a change in oxygen from adding in either glucose or pyruvate to one of the experiments, and I'm even more unsure of why there would be a change in oxygen concentration. E.g If glucose is added to a reaction tube with the cytosol of cells, do the oxygen levels decrease or stay the same as glucose cannot break down after glycolysis?

I have an answer from me attempting to figure out the question, but it's probably wrong

Any help would be greatly appreciated, thank you so much!

The oxygen level is measured by the oxygen electrode + oxygen meter.

This question is just testing whether you know where each stage of respiration occurs and which stage uses oxygen.

In order to use up oxygen, aerobic respiration has to occur. If only glycolysis is occurring then there won't be any glucose used up because it's an anaerobic process. You also need to pay attention to what is being added ie. adding glucose won't use up oxygen in a solution only containing mitochondria because glycolysis can't occur.

[f0od]

The oxygen level is measured by the oxygen electrode + oxygen meter.

This question is just testing whether you know where each stage of respiration occurs and which stage uses oxygen.

In order to use up oxygen, aerobic respiration has to occur. If only glycolysis is occurring then there won't be any glucose used up because it's an anaerobic process. You also need to pay attention to what is being added ie. adding glucose won't use up oxygen in a solution only containing mitochondria because glycolysis can't occur.

Thanks so much!
Also, for the glucose in the mitochondria solution, I know that glycolysis won't occur because of the lack of the cytosol, but would oxygen concentration decrease if the glucose is just taking up room? (sorry it's a dumb question)
And just wondering, is there any circumstance where the oxygen concentration would increase?

[PhoenixxFire]

Thanks so much!
Also, for the glucose in the mitochondria solution, I know that glycolysis won't occur because of the lack of the cytosol, but would oxygen concentration decrease if the glucose is just taking up room? (sorry it's a dumb question)
And just wondering, is there any circumstance where the oxygen concentration would increase?

Interesting question. Maybe, however if it did it would be a very minuscule decrease and is definitely overthinking it for this question. The correct answer would be no change.
Nah you're never going to get an increase in oxygen concentration when the only process going on is cellular respiration.

[f0od]

Interesting question. Maybe, however if it did it would be a very minuscule decrease and is definitely overthinking it for this question. The correct answer would be no change.
Nah you're never going to get an increase in oxygen concentration when the only process going on is cellular respiration.

Oooh ok
Thank you so much for your help!

[f0od]

Sorry for yet another question! 😅

Why is there an abundance of the enzyme ATPase on the thylakoid membrane?

I know that the enzyme ATPase is used to break down molecules, but the only thing I can think of is water being split to oxygen and hydrogen and doesn't that occur in the grana?