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March 30, 2024, 01:32:36 am

Author Topic: VCE Biology Question Thread  (Read 3571831 times)  Share 

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Quantum44

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Re: VCE Biology Question Thread
« Reply #9045 on: February 26, 2017, 07:39:54 pm »
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What is a cofactor and what is a coenzyme? How are they related? Are they organic? What are some common examples of each?

Thanks in advance

Cofactors and coenzymes are substances that are needed to be present for the enzyme to catalyse a reaction. They generally bind loosely and temporarily to a specific enzyme which allows it to perform its biological function. Cofactors are usually inorganic minerals and ions while coenzymes are usually organic vitamins.
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peanut

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Re: VCE Biology Question Thread
« Reply #9046 on: February 26, 2017, 08:22:33 pm »
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Cofactors and coenzymes are substances that are needed to be present for the enzyme to catalyse a reaction. They generally bind loosely and temporarily to a specific enzyme which allows it to perform its biological function. Cofactors are usually inorganic minerals and ions while coenzymes are usually organic vitamins.
Coenzymes are generally used up during the reaction. such as ATP (ATP gets converted to ADP).

zxcvbnm18

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Re: VCE Biology Question Thread
« Reply #9047 on: February 28, 2017, 06:14:04 pm »
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If photosynthesis occurs the best under red wavelength then why does this q 'consider the two groups of plants growing under artificial light sources ...... group 1: wavelength across the entire visible spectrum group 2 wavelengths restricted to the red region of the spectrum' have an answer that says plants growing under group 1 will have a high rate of photosynthesis than plants growing in group 2. .?

Cosidering the first line in my para...
I thought plants growing under group 2 conditions  will have a high rate of photosynthesis than group 1 bc under group 2 conditions, chlorophyll molecules are absorbing solely red wavelengths whereas chlorophyll molecules in group 1 are abosrbing not only red but others wavelgnths as well (blue etc.)

Gogo14

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Re: VCE Biology Question Thread
« Reply #9048 on: February 28, 2017, 06:45:26 pm »
+1
If photosynthesis occurs the best under red wavelength then why does this q 'consider the two groups of plants growing under artificial light sources ...... group 1: wavelength across the entire visible spectrum group 2 wavelengths restricted to the red region of the spectrum' have an answer that says plants growing under group 1 will have a high rate of photosynthesis than plants growing in group 2. .?

Cosidering the first line in my para...
I thought plants growing under group 2 conditions  will have a high rate of photosynthesis than group 1 bc under group 2 conditions, chlorophyll molecules are absorbing solely red wavelengths whereas chlorophyll molecules in group 1 are abosrbing not only red but others wavelgnths as well (blue etc.)
Chlorophyll also absorbs other wavelengths at the same time, but not as well. As the full specturm also includes red wavelength,It will be more than just red.
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Quantum44

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Re: VCE Biology Question Thread
« Reply #9049 on: February 28, 2017, 06:46:21 pm »
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If photosynthesis occurs the best under red wavelength then why does this q 'consider the two groups of plants growing under artificial light sources ...... group 1: wavelength across the entire visible spectrum group 2 wavelengths restricted to the red region of the spectrum' have an answer that says plants growing under group 1 will have a high rate of photosynthesis than plants growing in group 2. .?

Cosidering the first line in my para...
I thought plants growing under group 2 conditions  will have a high rate of photosynthesis than group 1 bc under group 2 conditions, chlorophyll molecules are absorbing solely red wavelengths whereas chlorophyll molecules in group 1 are abosrbing not only red but others wavelgnths as well (blue etc.)

I think the question operates under the assumption that both groups receive exactly the same number of light particles. So group 1 and group 2 will both receive an arbitrary number of light particles (500 for example). Group 2 will receive 500 particles of red light which will be absorbed the best by the chloroplasts and group 1  will receive 500 particles of white light, with a smaller percentage of light being absorbed by the chloroplasts compared to group 2.
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evelynmakris15

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Re: VCE Biology Question Thread
« Reply #9050 on: March 02, 2017, 09:45:15 pm »
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Does anyone know where to locate the Douchy's biology podcasts as they are no longer available on the iTunes podcast app!! Looked online but can't seem to find them :-\

vox nihili

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Re: VCE Biology Question Thread
« Reply #9051 on: March 03, 2017, 05:45:17 pm »
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Does anyone know where to locate the Douchy's biology podcasts as they are no longer available on the iTunes podcast app!! Looked online but can't seem to find them :-\

Further to the above, it would seem he's redoing them because of the new course perhaps?
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pap0007

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Re: VCE Biology Question Thread
« Reply #9052 on: March 04, 2017, 08:10:37 pm »
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hi guys!!

just wandering... we did a photosynthesis prac at school where we measured the effect of light on the rate of photosynthesis in algae balls. one was placed in the dark, on in light, one in light with red cellophane wrapped and one in light with blue cellophane wrapped around the test tube. i was wandering which theoretically should have the highest rate of photosynthesis? is it the clear test tube in the light?

thanks in advance:)

Arisa_90

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Re: VCE Biology Question Thread
« Reply #9053 on: March 04, 2017, 09:15:40 pm »
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I just wanted to ask this question out of curiosity.
What would happen if you remove an ovary from someone? Would the remaining one enlarge and work twice as hard to compensate for the removed ovary? Would this happen if you remove a testis from someone as well?

vox nihili

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Re: VCE Biology Question Thread
« Reply #9054 on: March 04, 2017, 10:31:38 pm »
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I just wanted to ask this question out of curiosity.
What would happen if you remove an ovary from someone? Would the remaining one enlarge and work twice as hard to compensate for the removed ovary? Would this happen if you remove a testis from someone as well?

I'm not entirely sure to be honest, and would be interested to hear what your research tells you.

In short though, yes you can be fertile with one testis. Likewise, I suspect that the same would be true of the ovary. I doubt the other would enlarge though. The capacity of the ovary to produce ova is really encoded at birth. The ovary stops making new eggs once you're born!

hi guys!!

just wandering... we did a photosynthesis prac at school where we measured the effect of light on the rate of photosynthesis in algae balls. one was placed in the dark, on in light, one in light with red cellophane wrapped and one in light with blue cellophane wrapped around the test tube. i was wandering which theoretically should have the highest rate of photosynthesis? is it the clear test tube in the light?

thanks in advance:)

Trust your experiment results! :)

Otherwise, you can work it out by looking at the absorbance spectra of chlorophyll. Look at which wavelength it absorbs light the best and you should be able to work it out from there. I'm not going to do that for you because it's a good exercise for you. :)
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anotherworld2b

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Re: VCE Biology Question Thread
« Reply #9055 on: March 05, 2017, 02:04:28 am »
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Hormones can influence cells in two ways. amine/protein and steriod. I was just wondering what happens to the hormone after combies with the recptor protein ? Is it destroyed?

TheAspiringDoc

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Re: VCE Biology Question Thread
« Reply #9056 on: March 05, 2017, 08:41:49 am »
+1
Douchy's podcasts can be found on the Apple podcasts app (purple app icon for those who don't use it ;))

beverlycheeeee

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Re: VCE Biology Question Thread
« Reply #9057 on: March 06, 2017, 01:18:59 pm »
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Hi there! I have a few questions on my practice sac that I have like no idea how to do, any help would be appreciated!

1.Manganese dioxode is an inorganic catalyst that speed up the same reaction as catalase. If it is a true catalyst, it should be possible to recover it and use again. Describe an experiment that you could carry out to test this hypothesis.

2. Catalase is an enzyme found in the liver of humans, it is responsible for the initial steps in the breakdown of hydrogen peroxide. A sample catalase was added to 4 test tube each containing a different concenreation of hydrogen peroxide and left to incubate at 37 degrees celcius. After the incubation of the amount of hydrogen peroxide remaining was measured after 10 minutes.

2a) What is the variable in this experiment. (Someone please explain the whole variable thing, please)
2b) Using the particle model explain the results obtained in this experiment by comparing the amount of hydrogen peroxide left at each of the concentrations.

3. What is the purpose of creating the standards in an experiment?

Thank you so much ;u;

vox nihili

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Re: VCE Biology Question Thread
« Reply #9058 on: March 06, 2017, 07:28:35 pm »
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Hormones can influence cells in two ways. amine/protein and steriod. I was just wondering what happens to the hormone after combies with the recptor protein ? Is it destroyed?

Sure is :)

Awesome question, shows you're really thinking
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christinett_

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Re: VCE Biology Question Thread
« Reply #9059 on: March 08, 2017, 08:17:39 pm »
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Hi, for Bio, ASAP, we need to write up an aim and a hypothesis for the following experiment and i was wondering if what i have is good / what can be changed and improved?

All help is appreciated, thanks
Each beaker is filled with 100ml of water and a 90g sachet of gelatine
Beaker 1 - Fresh pineapple and hot water
Beaker 2 - Fresh pineapple and room temp water
Beaker 3 - Canned pineapple and hot water
Beaker 4 - Canned pineapple and room temp water

Aim: To investigate the effect of temperature on the enzyme, bromelain in pineapple.

Hypothesis:
At room temperature, the beakers with fresh pineapple will remain liquid, due to maximal activity of bromelain
At boiling temperature, the beakers with fresh pineapple and gelatine will solidify, due to the denaturing of bromelain
At room temperature, the beakers with canned pineapple and gelatine will become slightly gelled due to the slight effect on bromelain
At boiling temperature, the beakers with canned pineapple and gelatine will solidify, due to the denaturing of bromelain.
The fresh pineapple will be able to break down more of the gelatine with a great amount of enzymes active.