VCE Biology Question Thread

[Reus]

What exactly goes into a conclusion of a prac report?

Is it true we need to reinstate our hypothesis and further expand on it?

Reinstate the aim of the practical, make mentions of the results and whether they support or do no support your hypothesis. That's it really. Two sentences should suffice.

Never add new information.

[winchesteraddict]

Can facilitated diffusion be both active and passive?
I think it can as both FD and AT use carrier proteins idk i might be wrong.

Thanks in advance

[cosine]

Can facilitated diffusion be both active and passive?
I think it can as both FD and AT use carrier proteins idk i might be wrong.

Thanks in advance

No, facilitated diffusion uses both carrier proteins AND protein channels, however, they require no energy at all as they go from a high concentration to a low one. Active transport ONLY uses carrier proteins, and requires energy because it goes from a low concentration to a high one.

I think were you're confused is 'oh how come two processes can use carrier proteins'?
Well, active transport and facilitated diffusion use them. There is only one different, if a substance is going down its concentration gradient, then it's facilitated. If the substance is going against it's concentration gradient, then it's active.

Hope it helped

[twinkling star]

Had a couple of questions:

- are antigen presentation and signal transmission over a synapse examples of juxtracrine (contact-dependent) signalling?

- what's the difference between a 'disease' and a 'disorder'?

- what's the difference between a virus and a virion?

- do pathogens cause any harm to intermediate (secondary) hosts?

- is bacterial conjugation a form of sexual reproduction?

Thanks!

[KingDrogba]

To how much detail do we need to understand the Calvin Cycle?

Cheers

[grannysmith]

To how much detail do we need to understand the Calvin Cycle?

Cheers

Know where it occurs, the inputs and outputs (you don't need to know any numbers, really) and a very brief outline of what happens. Very brief.

[Reus]

To how much detail do we need to understand the Calvin Cycle?

Cheers

Your name though!!

[KingDrogba]

Your name though!!

Cheers dude, all praise the king

[cosine]

Question about enzymes:

If enzymes reduce the activation energy require for a reaction to initiate, does this mean that comparing it to a reaction without the enzyme, that it would occur at a rapid rate, that is, the product/s will be released faster than usual?

Im also not getting my hear around enzyme concentration and how it can affect the rate of reactions.

Any help si greatly appreciated, thank you.

[scarletmoon]

Question about enzymes:

If enzymes reduce the activation energy require for a reaction to initiate, does this mean that comparing it to a reaction without the enzyme, that it would occur at a rapid rate, that is, the product/s will be released faster than usual?

Im also not getting my hear around enzyme concentration and how it can affect the rate of reactions.

Any help si greatly appreciated, thank you.

Without the enzyme the reaction would take a lot longer to reach the activation energy required for the reaction to continue, hence the rate of reaction (products released) will be incredibly slow, too slow to sustain life. With enzymes this activation energy is lowered so the reaction takes less time to proceed to completion.
The more enzymes you have the faster the rate of reaction will be as there is an increased chance that the substrate will bind to the active site of an enzyme and be turned into product. However continuing to add enzymes does not continue to increase the rate of reaction, after a certain point, adding enzymes will no longer increase rate of reaction ( the rate of reaction won't increase due to other factors like not enough substrate, temperature etc.)

I really hope this made sense, ask if there's any part that confused you

[scarletmoon]

Had a couple of questions:

- are antigen presentation and signal transmission over a synapse examples of juxtracrine (contact-dependent) signalling?

- what's the difference between a 'disease' and a 'disorder'?

- what's the difference between a virus and a virion?

- do pathogens cause any harm to intermediate (secondary) hosts?

- is bacterial conjugation a form of sexual reproduction?

Thanks!

1. I don't think you need to know this
2. A disease is anything that causes an impairment in bodily functions, caused by extrinsic causes (viruses, bacteria) a disorder is abnormalities in body function due to genetic mutations (I think just double check that)
3. Virus is a non cellular disease causing agent that can only replicate inside living cells. Virion is the same thing it just refers to the whole virus particle, including the protein capsule and the core of Nucleic acid. (Usually the word virus is used)
4. No they don't or else their source of food and shelter will be destroyed
5. Yes it is a form of assexual reproduction (not sexual) as there is exchange of genetic material

Hope this helped in some way

[cosine]

Without the enzyme the reaction would take a lot longer to reach the activation energy required for the reaction to continue, hence the rate of reaction (products released) will be incredibly slow, too slow to sustain life. With enzymes this activation energy is lowered so the reaction takes less time to proceed to completion.
The more enzymes you have the faster the rate of reaction will be as there is an increased chance that the substrate will bind to the active site of an enzyme and be turned into product. However continuing to add enzymes does not continue to increase the rate of reaction, after a certain point, adding enzymes will no longer increase rate of reaction ( the rate of reaction won't increase due to other factors like not enough substrate, temperature etc.)

I really hope this made sense, ask if there's any part that confused you

Thanks a lot

What are inhibitors? And why are they used?

[scarletmoon]

Inhibitors are any  molecules or competing substrate the binds to the enzyme and decreases it's activity. The inhibitor may either bind to the active site (preventing the substrate from binding to the active site) or bind to another part of the enzyme, which deforms the shape of the active site so it's unable to bind to the substrate and catalyse the required reaction.

Drugs are the most common type of inhibitors. Some drugs inhibit enzymes that are required for pathogens to survive.

There's also different types of inhibition like reversible and irreversible inhibition but these should be outlined in your textbook

[Reus]

Inhibitors are any  molecules or competing substrate the binds to the enzyme and decreases it's activity. The inhibitor may either bind to the active site (preventing the substrate from binding to the active site) or bind to another part of the enzyme, which deforms the shape of the active site so it's unable to bind to the substrate and catalyse the required reaction.

Drugs are the most common type of inhibitors. Some drugs inhibit enzymes that are required for pathogens to survive.

There's also different types of inhibition like reversible and irreversible inhibition but these should be outlined in your textbook

This is known as the allosteric site.

[vanessa14]

hey guys! So I had my prac for biology unit 3 and 4, on Osmosis, with the eggs , and I was just wondering has anyone done it already?
I could use a little help on what to write up for my discussion 
thanks!!