VCE Biology Question Thread

[PhoenixxFire]

If I got 60 in my first 3/4 sac have I lost my chances of getting a 40+

You haven't lost your chance, it'll just be harder. That first sac is only worth 8% of your study score so you have plenty of opportunity to make up for it, however you will have to do something differently in your study or preparation so that you can score higher on future sacs and the exam.

[AaronAnton]

What is it meant by when enzymes lower their activation energy? What exactly is activation energy?

Hey MM1!

A simple definition of activation energy is basically the energy that needs to be provided to initiate a reaction. In this case, enzymes bind to substrates/molecules and modify them so that the energy required for a reaction is lowered. This, in turn, allows the progress of a reaction to speed up.

I hope this helps you! If you need some more clarification please feel free to reply! 

[ErnieTheBirdi]

I’m really stressed and worried right now. I just had my Outcome 1 for 3/4 Biology and I wanted to know if I got 86-89% or if I get 90% will I be able to still get 45+ study score assuming that I will get 90-92% plus for the upcoming SACs and exam? Can someone tell me what sort of grades I’ll need for SACs and Exams to get a 45+ study score? Please help! Please

[Chocolatemilkshake]

I’m really stressed and worried right now. I just had my Outcome 1 for 3/4 Biology and I wanted to know if I got 86-89% or if I get 90% will I be able to still get 45+ study score assuming that I will get 90-92% plus for the upcoming SACs and exam? Can someone tell me what sort of grades I’ll need for SACs and Exams to get a 45+ study score? Please help! Please

Again, this is more suited here, but of course! Ultimately it is not your SAC scores that matter but your ranking within your cohort and your exam score. In fact, you could receive much lower scores and still receive 45+, as long as your school SACs scale up and you receive a good exam score.

I'd say be a little less stressed on your scores and focus on really understanding the content at the moment

[ErnieTheBirdi]

thank you, sorry I didn’t know that that was a thread. Also its my first 3/4 SAC and its also my first 3/4 subject and I’m doing it a year early so that why I’m super stressed about it. Also our teacher told us in order to get high 40s as a study score we need to hold on to 90+ scores across all SACs and Exams so thats why I asked. Thank-you though

[Snow Leopard]

Hey,

What's the difference between ATP and glucose? (they seem to have similar functions)

Thanks in advance!

[whys]

Hey,

What's the difference between ATP and glucose? (they seem to have similar functions)

Thanks in advance!

ATP is an energy-carrying molecule. Glucose is a monosaccharide that provides the body with energy. Glucose cannot readily be used by the body. If glucose was combusted at once, then cells would probably explode due to the magnitude of the reaction, which is why glucose is broken down by many processes over a period of time. This is why glucose needs to be converted to ATP to be used. ATP is a useful form of energy due to its efficiency despite having small amounts of energy stored in its bonds, while glucose cannot be used by the body straight away. Apart from this, they have obvious structural differences.

(correct me if I'm wrong!)

[Sine]

ATP is an energy-carrying molecule. Glucose is a monosaccharide that provides the body with energy. Glucose cannot readily be used by the body. If glucose was combusted at once, then cells would probably explode due to the magnitude of the reaction, which is why glucose is broken down by many processes over a period of time. This is why glucose needs to be converted to ATP to be used. ATP is a useful form of energy due to its efficiency despite having small amounts of energy stored in its bonds, while glucose cannot be used by the body straight away. Apart from this, they have obvious structural differences.

(correct me if I'm wrong!)

I would probably be careful with saying "glucose needs to be converted to ATP". Glucose is not converted to ATP. Glucose is used to produce ATP. The chemical reactions that glucose undergoes results in the product of ATP as a byproduct. Furthermore, other byproducts of these reactions such as NADH2 and FADH can be used to product ATP via oxidative phosphorylation.

[Snow Leopard]

ATP is an energy-carrying molecule. Glucose is a monosaccharide that provides the body with energy. Glucose cannot readily be used by the body. If glucose was combusted at once, then cells would probably explode due to the magnitude of the reaction, which is why glucose is broken down by many processes over a period of time. This is why glucose needs to be converted to ATP to be used. ATP is a useful form of energy due to its efficiency despite having small amounts of energy stored in its bonds, while glucose cannot be used by the body straight away. Apart from this, they have obvious structural differences.

(correct me if I'm wrong!)

I would probably be careful with saying "glucose needs to be converted to ATP". Glucose is not converted to ATP. Glucose is used to produce ATP. The chemical reactions that glucose undergoes results in the product of ATP as a byproduct. Furthermore, other byproducts of these reactions such as NADH2 and FADH can be used to product ATP via oxidative phosphorylation.

Thanks!
Would it be correct to say that glucose is too big of a molecule to be used by cells so it's broken down and in the process of it being broken down, ATP (which the cell can use for energy) is produced?

[Sine]

Thanks!
Would it be correct to say that glucose is too big of a molecule to be used by cells so it's broken down and in the process of it being broken down, ATP (which the cell can use for energy) is produced?

I think ATP is actually a bigger molecule than glucose.

As whys has already said the biochemical reason for ATP being used for energy and not glucose directly is due to the potential huge release of energy if glucose was directly converted to pyruvate. This would also require a heap of energy input. That is why glycolysis occurs in ten steps - it allows the breakdown of glucose to be regulated and some of the steps assisted by coupling to other reactions (e.g. the input of ATP).

[yhoblos]

I have a question. In class we were taught that glucose could only pass through the plasma membrane if it uses a carrier protein. But on Edrolo it said that VCAA wants us to say channel protein instead. Which one is it?

[ErnieTheBirdi]

Hey everyone I recently just got 81 on my 3/4 bio SAC1 and I was wondering have I lost my chance to get 45+ as a study score?

[J_Rho]

I have a question. In class we were taught that glucose could only pass through the plasma membrane if it uses a carrier protein. But on Edrolo it said that VCAA wants us to say channel protein instead. Which one is it?

Hey yhoblos,
Great question! The study design doesn't specify any types of integral proteins let alone the specific names to use, however, channel proteins and carrier proteins are different.

Channel proteins span the membrane and make hydrophilic tunnels across it, allowing their target molecules to pass through by diffusion. Channels are very selective and will accept only one type of molecule (or a few closely related molecules) for transport. Passage through a channel protein allows polar and charged compounds to avoid the hydrophobic core of the plasma membrane, which would otherwise slow or block their entry into the cell.
Another class of transmembrane proteins involved in facilitated transport consists of the carrier proteins. Carrier proteins can change their shape to move a target molecule from one side of the membrane to the other. Like channel proteins, carrier proteins are typically selective for one or a few substances. Often, they will change shape in response to binding of their target molecule, with the shape change moving the molecule to the opposite side of the membrane. The carrier proteins involved in facilitated diffusion simply provide hydrophilic molecules with a way to move down an existing concentration gradient (rather than acting as pumps).
Channel and carrier proteins transport material at different rates. In general, channel proteins transport molecules much more quickly than do carrier proteins. This is because channel proteins are simple tunnels; unlike carrier proteins, they don’t need to change shape and “reset” each time they move a molecule. A typical channel protein might facilitate diffusion at a rate of tens of millions of molecules per second, whereas a carrier protein might work at a rate of a thousand or so molecules per second

TL;DR - Channel proteins are like a tunnel for specific proteins


 carrier proteins are like those airlock things on a spaceship - you enter one door your shut in there until you can exit the other side


Hopefully that clarified things! 😂😬

[SS1314]

I have a question. In class we were taught that glucose could only pass through the plasma membrane if it uses a carrier protein. But on Edrolo it said that VCAA wants us to say channel protein instead. Which one is it?

I am pretty sure it is carrier proteins as they generally facilitate the diffusion of larger uncharged polar molecules, while channel proteins simply have narrow water-filled pores that provide a hydrophilic environment for small polar molecules and ions to cross through.

However I am not 100% sure whether channel proteins are able to facilitate the diffusion of glucose molecules however I am sure that carrier proteins are.

[whys]

Hello everyone! I have a few questions:

What happens to the extra phosphate group in ATP when broken down into ADP? Where does it go?

Did eukaryotic cells engulf photosynthetic microbes (now known as chloroplasts)/mitochondria or did prokaryotes engulf photosynthetic microbes/mitochondria to become eukaryotes (in the endosymbiotic theory)?

Thank you!