VCE Biology Question Thread

[GodNifty]

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

TBH, I don't know. I would assume it would go through a phosphorylation process or undergo autophagy with a lysosome. The latter seems more plausible

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)?

The mitochondria originated from an aerobic prokaryote (proteobacteria) and a chloroplast originated from a cyanobacteria. Anaerobic bacteria (which is a prokaryote) engulfed both the mitochondria and chloroplast.

[ajka0002]

Hey all!
Can someone please explain what NADH and FADH2 are and what they do in cellular respiration??
Thank you

[ajka0002]

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?

Nope. My teacher was telling us that a girl a few years ago didn't do the best on her SACs (not horribly, but not 100%) and she got a 50 study score, from the exam.

[Sine]

Hey all!
Can someone please explain what NADH and FADH2 are and what they do in cellular respiration??
Thank you

I think the basic understanding for VCE you need is that they are electron/hydrogen carriers which provide electrons to the electron transport chain in order to produce ATP via oxidative phosphorylation. Also that these molecules are recycled.

[whys]

Hey all!
Can someone please explain what NADH and FADH2 are and what they do in cellular respiration??
Thank you

NADH and FADH2 are loaded co-enzymes used in cellular respiration. Co-enzymes are organic, non-protein molecules that bind to an enzyme to contribute to its function, and aren't useful on their own. The term 'loaded' means they have accepted protons and electrons. They first exist as NAD+ and FAD, which are their unloaded forms. In glycolysis, NADH is made from NAD+ as it accepts a hydrogen ion and 2 electrons, which is directly carried to be used in the electron transport chain. In the Kreb's cycle, 3 NADH are made per pyruvate, and 1 FADH2 is made per pyruvate, so in total 6 NADH and 2 FADH2 is made for 1 glucose molecule. In the electron transport chain, the two loaded co-enzymes are converted back into NAD+ and FAD and is cycled back to glycolysis where it can be used again. The electrons they have lost here are used to make ATP. The leftover hydrogen ions combine with oxygen to form 6 H2O, which is an output of cellular respiration.

Essentially, these molecules act as electron carriers. Their job is to transport electrons to wherever they are needed, then go back to their unloaded forms to do it all again!

[Owlbird83]

Can someone please tell me what the total ATP yield is in aerobic respiration. Online it is saying 36-38, which is what I thought, but in the Biozone it says 32 ATP.

36 is produced altogether in most cells (38 in certain types of cells).
If you look at each stage
-Glycolysis: 2ATP
-Krebs Cycle: 2ATP
-Electron transport chain: 32 ATP

[caffinatedloz]

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?

The extra phosphate (and the ADP for that matter) are continually reused by the cell. So after ATP becomes ADP and a phosphate as the bond between the two is broken and the energy created is used, it diffuses through the cell to an area of low concentration (near the mitochondria) where they are rejoined to create more energy currency that can be used in the cell.

There's a really great Edrolo video that explains it if your school has access to that resource.

Hope this helps!

[SmartWorker]

Hey,

Has anyone used EDROLO for bio 3/4, if so please explain your experience with it? How you used it and what aspects provided major benefit.

Thank you

[J_Rho]

Hey,

Has anyone used EDROLO for bio 3/4, if so please explain your experience with it? How you used it and what aspects provided major benefit.

Thank you

I watch it before every class so I go in with a foundation understanding it also helps break down and understand each study design dot point too, overall I love it but don't rely on it completely I would supplement it with a textbook however edrolo also offers a bio textbook which is the best in terms of clarity and succinctness. But if only using the videos definitely get a textbook as edrolo skims over some of the topics you need to know and the exam questions that are at the end of each video/section are super helpful!

[Evolio]

Hey SmartWorker!

I've used Edrolo for Biology Units 3 4 and I personally found it very useful. I used it to get ahead in the course so that I could get previous exposure to the topics. Andrew Douch, the teacher also explains things really clearly and concisely and it helps consolidate your knowledge as well. Also, to make sure we weren't just watching Biology videos, they also added exam questions so that you're doing practise along the way to consolidate your learning which I found useful as well.

I agree with J_Rho that it shouldn't be used as a stand alone resource because sometimes it doesn't go into much depth into topics you need to know a lot of information about.

[Chocolatemilkshake]

Hey,

Has anyone used EDROLO for bio 3/4, if so please explain your experience with it? How you used it and what aspects provided major benefit.

Thank you

Hi Smartworker,
I personally found Edrolo really good and a great supplementary resource for revision or learning ahead of content (I didn't use the textbook version though, just the videos).

I enjoyed the way Andrew Douch explained concepts (with passion) and usually the right amount of detail. Furthermore, I liked that sometimes I could rewatch videos or topics I was struggling with while doing other things (eg. on the bus, doing the dishes, etc). Plus I really liked that he went into some topics with a little more detail (but be careful though as I did find some topics were skimmed over a little bit - eg. human evolution is not covered in depth from the version I used last year).

Overall, compared to other edrolo videos, I'd definitely rate the biology course the best one and the most helpful/worth your time. However, obviously it depends how you learn best and how much you get out of watching videos. For me, I took down key notes when watching the videos the first time and did all the questions, then often reviewed the topics I couldn't remember well nearing the exam.

If you haven't already bought Edrolo, I'd recommend using "Douchy's Biology" which are free podcasts of equal benefit (but obviously without the practice questions).
Hope this helps 

EDIT: Evolio and J_Rho beat me too it, but totally agree with them

[J_Rho]

Anyone got a good simple definition of polar molecules and nonpolar molecules?

[SS1314]

Anyone got a good simple definition of polar molecules and nonpolar molecules?

Polar molecules are covalent molecules in which electrons are not evenly distributed, so some parts of the molecule are slightly negative while others are slightly positive. For example, the two hydrogen atoms in H2O molecules are slightly positive while the oxygen atom is slightly negative simply due to the fact that oxygen is more electronegative (has a greater electron attracting power). Non-polar molecules are the opposite as there is no overall unequal sharing of electrons.

EDIT: for the sake of Biology you just need to know that polar molecules interact with other polar molecules while non polar molecules interact with other non polar molecules.

[J_Rho]

Polar molecules are covalent molecules in which electrons are not evenly distributed, so some parts of the molecule are slightly negative while others are slightly positive. For example, the two hydrogen atoms in H2O molecules are slightly positive while the oxygen atom is slightly negative simply due to the fact that oxygen is more electronegative (has a greater electron attracting power). Non-polar molecules are the opposite as there is no overall unequal sharing of electrons.

EDIT: for the sake of Biology you just need to know that polar molecules interact with other polar molecules while non polar molecules interact with other non polar molecules.

Thanks! Would it be correct to say that nonpolar molecules have electrons that are equal btwn atoms OR when polar bonds cancel each other out?

[SS1314]

Thanks! Would it be correct to say that nonpolar molecules have electrons that are equal btwn atoms OR when polar bonds cancel each other out?

I think the best definition would be that in non polar molecules the polar bonds cancel out, as you have mentioned, due to the symmetry of the molecular structure OR the molecule contains no polar bonds in the first place (eg. O2).

Hope this helps