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March 29, 2024, 08:29:13 pm

Author Topic: VCE Biology Question Thread  (Read 3571525 times)  Share 

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PopcornTime

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Re: VCE Biology Question Thread
« Reply #10170 on: April 25, 2018, 01:16:45 pm »
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Can someone check the following answers:

How do enzymes catalyse reactions?
By lowering the activation energy required for the reaction to occur.

In what situations is enzyme inhibition permanent?

In what situations is enzyme inhibition not permanent?

What is the difference between denatured and deactivated?
- denatured is irreversible
- deactivated is reversible

What is the difference and similarities between cofactors and coenzymes?
- cofactors and coenzymes both bind to the enzymes allosteric site
- cofactors are inorganic, whereas coenzymes are organic

What is an enzyme controlled biochemical pathway?
- a series of chemical reactions inside a cell that are controlled by the action of enzymes

PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10171 on: April 25, 2018, 01:27:29 pm »
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Can someone check the following answers:

How do enzymes catalyse reactions?
By lowering the activation energy required for the reaction to occur. Yep

In what situations is enzyme inhibition permanent? Have a guess at these. It has to do with the types of inhibition

In what situations is enzyme inhibition not permanent?

What is the difference between denatured and deactivated?
- denatured is irreversible
- deactivated is reversible For VCE just talk about denaturation and make sure you specify that it is permanently denatured when it far exceeds its optimum temperature. I don't know enough about the specifics to distinguish between them, denaturation does not have to be permanent though (but it is for VCE)

What is the difference and similarities between cofactors and coenzymes?
- cofactors and coenzymes both bind to the enzymes allosteric site They don't necessarily bind to the allosteric site, they could bind to the active site.
- cofactors are inorganic, whereas coenzymes are organic I've seen this fairly often. I've always been told that coenzymes are a type of cofactor - therefore cofactors can be organic or inorganic, but if anyone thinks differently feel free to say so because I'm not entirely sure.

What is an enzyme controlled biochemical pathway?
- a series of chemical reactions inside a cell that are controlled by the action of enzymes Yep. You should probably put 'specific' in there somewhere because you should always say specific when talking about enzymes.

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MAGGOT

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Re: VCE Biology Question Thread
« Reply #10172 on: April 25, 2018, 03:12:33 pm »
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I read somewhere this:
The gap or junction between the axon of one neuron and the dendrites of the next, or between the axon and an effector is called a synapse.
1) is the first part the part of the sentence right?
2) is the axon the length of all the myelin sheath joined together?

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Re: VCE Biology Question Thread
« Reply #10173 on: April 25, 2018, 03:27:48 pm »
+3
I read somewhere this:
The gap or junction between the axon terminal of one neuron and the dendrites of the next, or between the axon terminal and an effector is called a synapse. Also called a synaptic gap or synaptic cleft
1) is the first part the part of the sentence right? Is now
2) is the axon the length of all the myelin sheath joined together?Sort of. The axon is coated in myelin.
Image

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fruitbowl34

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Re: VCE Biology Question Thread
« Reply #10174 on: April 25, 2018, 03:38:30 pm »
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Hi! Does anyone know how are photosynthesis and enzymes linked?? and why are they important as part of key cellular processes of the cell?? Thanks! :)

Sine

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Re: VCE Biology Question Thread
« Reply #10175 on: April 25, 2018, 03:41:50 pm »
+1
I read somewhere this:
The gap or junction between the axon of one neuron and the dendrites of the next, or between the axon and an effector is called a synapse.
1) is the first part the part of the sentence right?
2) is the axon the length of all the myelin sheath joined together?
keep in mind that all neurons aren't myelinated so you can't really use that. Also there are small gaps called nodes on ranvier between the schwann cells (for the purpose of vce biology schwann cells forms the myelin sheath).
Yes as others have said the synapse is the space between the axon terminal and dendrites but can also be between an axon terminal and effector muscle/gland.

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Re: VCE Biology Question Thread
« Reply #10176 on: April 25, 2018, 03:44:09 pm »
+1
Hi! Does anyone know how are photosynthesis and enzymes linked?? and why are they important as part of key cellular processes of the cell?? Thanks! :)
Cellular reactions can't* occur without enzymes. In photosynthesis a large number of chemical reactions are needed (called a biochemical pathway) to build glucose. Pretty much every cellular process needs enzymes to catalyse the reactions that allow them to occur.

*Well they can but its too slow to sustain life
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fruitbowl34

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Re: VCE Biology Question Thread
« Reply #10177 on: April 25, 2018, 03:53:01 pm »
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Cellular reactions can't* occur without enzymes. In photosynthesis a large number of chemical reactions are needed (called a biochemical pathway) to build glucose. Pretty much every cellular process needs enzymes to catalyse the reactions that allow them to occur.

*Well they can but its too slow to sustain life

I see! So without enzymes these cellular processes won't be able to occur? and what would happen to the cells if they don't occur?

Sine

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Re: VCE Biology Question Thread
« Reply #10178 on: April 25, 2018, 03:55:39 pm »
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I see! So without enzymes these cellular processes won't be able to occur? and what would happen to the cells if they don't occur?
these processes do occur without enzymes however they would be too slow to sustain life

the impact would depend on which enzyme was not working properly.
could be a complete loss of function or maybe reduced function
« Last Edit: April 25, 2018, 03:57:29 pm by Sine »

PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10179 on: April 25, 2018, 03:56:54 pm »
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I see! So without enzymes these cellular processes won't be able to occur? and what would happen to the cells if they don't occur?
Death (if they all stop)
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fruitbowl34

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Re: VCE Biology Question Thread
« Reply #10180 on: April 25, 2018, 04:32:46 pm »
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Hey again! I just want to make sure I've got this right, so I understand that as light intensity increases so does the rate of photosynthesis and if there's too much light it reaches a light saturation point. But if there's too little light that means the light-dependent stage won't be able to take place. For CO2 concentration it also reaches a certain point where the enzymes are saturated, but I'm not sure what stages it would affect and how.

PhoenixxFire

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Re: VCE Biology Question Thread
« Reply #10181 on: April 25, 2018, 04:39:18 pm »
+1
Hey again! I just want to make sure I've got this right, so I understand that as light intensity increases so does the rate of photosynthesis and if there's too much light it reaches a light saturation point. But if there's too little light that means the light-dependent stage won't be able to take place. For CO2 concentration it also reaches a certain point where the enzymes are saturated, but I'm not sure what stages it would affect and how.
CO2 is an input of the light independent stage so it would effect that. Both light intensity and CO2 concentration (and all other limiting factors) would actually slow down both reactions though as the light independent stage requires products from the light dependant stage and the light dependant stage needs the NADP+ from the light independent stage.
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Scribe

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Re: VCE Biology Question Thread
« Reply #10182 on: April 25, 2018, 06:21:44 pm »
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Hey everyone,

I have a photosynthesis SAC tomorrow in which we design an experiment, perform a prac and present the findings in the form of a poster.
How could I improve this hypothesis?

1) If Elodea Canadensis is exposed to blue wavelengths of light, then the rate of photosynthesis will be highest.

2) If Elodea Canadensis is exposed to blue wavelengths of light, then the rate of photosynthesis will be highest compared to other wavelengths of light.

Thank you! :)

Edited to include the second hypothesis.
« Last Edit: April 25, 2018, 06:26:56 pm by Scribe »

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Re: VCE Biology Question Thread
« Reply #10183 on: April 25, 2018, 06:30:24 pm »
+1
Better to just say ‘blue light’ assuming your just using cellophane and not proper equipment.

If you are using two colours refer to both of them, if you’re using more than 2 say X will have the highest and Y will have the lowest.
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Scribe

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Re: VCE Biology Question Thread
« Reply #10184 on: April 25, 2018, 06:38:10 pm »
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Thank you very much! We are using five different colours of cellophane.

How would say X will have the highest and Y will have the lowest? My teacher recommended that we follow the general structure "If..., then..."

I am not sure if I have implemented your suggestions correctly.

1) If Elodea Canadensis is exposed to blue light, then the rate of photosynthesis will be highest compared to other colours of light.

2) If Elodea Canadensis is exposed to blue light, then the rate of photosynthesis will be highest while the rate of photosynthesis will be lowest when the plant is exposed to green light.