VCE Biology Question Thread

[jk006915]

I have a question. Why are complementary bases complementary?

Wow, everyone seems to be working hard here. I don't feel prepared for biology 3/4 -_- probably my fault anyway though. And does anyone know if chapter 4 of NOB is necessary? 'Cause I'm focussing on the first 3 chapters more.

[TheAspiringDoc]

I have a question. Why are complementary bases complementary?

Wow, everyone seems to be working hard here. I don't feel prepared for biology 3/4 -_- probably my fault anyway though. And does anyone know if chapter 4 of NOB is necessary? 'Cause I'm focussing on the first 3 chapters more.

adenine and thymine share two hydroen bonds, whereas cytosine and guanine share 3. So compatability is the answer, I suppose

[piggylywinks]

Awesome, thanks! No rush

To answer you queston Ace77777:

 the main difference between the Golgi Body and the two ER's is that the Golgi packages packages proteins/hormones etc. for transportation OUTSIDE the cell i.e exocytosis. The ER mainly synthesizes and transports proteins/hormones etc. inside the cell e.g intracellular.

As for the stages of glycolysis, according to my teach (who is a VCAA assessor) this year they are mainly concerned with the products of glycolysis only (although, you might need to check with your teacher on this.) However, it would be useful to learn the stages of the Electron Transport Chain and the Krebs Cycle in detail, as (again quoting my teacher) is what VCAA is aiming to focus on.

A quick check of the Study Design says:
- "requirements for aerobic and anaerobic cellular respiration: the location, and main inputs and
outputs, of glycolysis; the structure of the mitochondrion and its function in aerobic cellular
respiration including main inputs and outputs of the Krebs Cycle and the electron transport
chain."

Please feel free to message me with any other questions
Good Luck

[geminii]

To answer you queston Ace77777:

 the main difference between the Golgi Body and the two ER's is that the Golgi packages packages proteins/hormones etc. for transportation OUTSIDE the cell i.e exocytosis. The ER mainly synthesizes and transports proteins/hormones etc. inside the cell e.g intracellular.

As for the stages of glycolysis, according to my teach (who is a VCAA assessor) this year they are mainly concerned with the products of glycolysis only (although, you might need to check with your teacher on this.) However, it would be useful to learn the stages of the Electron Transport Chain and the Krebs Cycle in detail, as (again quoting my teacher) is what VCAA is aiming to focus on.

A quick check of the Study Design says:
- "requirements for aerobic and anaerobic cellular respiration: the location, and main inputs and
outputs, of glycolysis; the structure of the mitochondrion and its function in aerobic cellular
respiration including main inputs and outputs of the Krebs Cycle and the electron transport
chain."

Please feel free to message me with any other questions
Good Luck

Thank you very much! The insight from someone who has a teacher who is also an assessor is much appreciated. I'll PM you if I have any specific questions!
Thanks again

[vox nihili]

To answer you queston Ace77777:

 the main difference between the Golgi Body and the two ER's is that the Golgi packages packages proteins/hormones etc. for transportation OUTSIDE the cell i.e exocytosis. The ER mainly synthesizes and transports proteins/hormones etc. inside the cell e.g intracellular.

As for the stages of glycolysis, according to my teach (who is a VCAA assessor) this year they are mainly concerned with the products of glycolysis only (although, you might need to check with your teacher on this.) However, it would be useful to learn the stages of the Electron Transport Chain and the Krebs Cycle in detail, as (again quoting my teacher) is what VCAA is aiming to focus on.

A quick check of the Study Design says:
- "requirements for aerobic and anaerobic cellular respiration: the location, and main inputs and
outputs, of glycolysis; the structure of the mitochondrion and its function in aerobic cellular
respiration including main inputs and outputs of the Krebs Cycle and the electron transport
chain."

Please feel free to message me with any other questions
Good Luck

Just going to add, in case people get a little bit confused, proteins that are packaged and exocytosed by the Golgi are still synthesised by the ER.



On respiration though, the reading of the study design makes it fairly clear that you don't need to know the stages of glycolysis, nor indeed the stages of the Krebs cycle. Your teacher seems to be mistaken about the expectations of the VCE Biology course. My advice would be to save your time and energy and avoid trying to learn the details of the Krebs cycle. Furthermore, it would be impossible to learn the stages of the electron transport chain because there really aren't any (this is debatable, some will disagree with this).

I have a question. Why are complementary bases complementary?

Wow, everyone seems to be working hard here. I don't feel prepared for biology 3/4 -_- probably my fault anyway though. And does anyone know if chapter 4 of NOB is necessary? 'Cause I'm focussing on the first 3 chapters more.

adenine and thymine share two hydroen bonds, whereas cytosine and guanine share 3. So compatability is the answer, I suppose

To add to this: basically adenine and thymine are structured in such a way that they can form two hydrogen bonds, whereas guanine and cytosine are structured in such a way that they can form three. In other words, the pieces of the puzzle just fit together. Adenine and guanine, for instance, can bond to each other, but it's just not as efficient as with their complementary pairs.

[geminii]

Just going to add, in case people get a little bit confused, proteins that are packaged and exocytosed by the Golgi are still synthesised by the ER.



On respiration though, the reading of the study design makes it fairly clear that you don't need to know the stages of glycolysis, nor indeed the stages of the Krebs cycle. Your teacher seems to be mistaken about the expectations of the VCE Biology course. My advice would be to save your time and energy and avoid trying to learn the details of the Krebs cycle. Furthermore, it would be impossible to learn the stages of the electron transport chain because there really aren't any (this is debatable, some will disagree with this).

Thanks for this! Just to clarify, my teacher didn't tell us that we had to learn all the stages etc. of glycolysis - I was studying ahead and found these ten insanely complicated steps and I was just hoping I didn't need to memorise them!

[TheAspiringDoc]

Some bits of this may be a little above VCE level

Hey so can someone confirm if my understanding of protein structures is correct? (and also I'd greatly appreciate any feedback on my wording)

Primary structure: specific sequence of amino acids

Secondary structure: coiled or pleated structure within polypeptide chain caused by interactions between the backbones (i.e. non-variable part) of amino acids. Includes alpha-helices and beta-pleated sheets.

Tertiary structure: overall three-dimensional structures of the polypeptide chain (composed of secondary structures) caused by interactions between the R-groups (i.e. variable regions) of amino acids.

Quaternary structure: multiple polypeptide chains joined together. Not found in all proteins.

I'm particularly interested in knowing if the bolded bits are correct.

Thanks!

[geminii]

Some bits of this may be a little above VCE level

Hey so can someone confirm if my understanding of protein structures is correct? (and also I'd greatly appreciate any feedback on my wording)

Primary structure: specific sequence of amino acids

Secondary structure: coiled or pleated structure within polypeptide chain caused by interactions between the backbones (i.e. non-variable part) of amino acids. Includes alpha-helices and beta-pleated sheets.

Tertiary structure: overall three-dimensional structures of the polypeptide chain (composed of secondary structures) caused by interactions between the R-groups (i.e. variable regions) of amino acids.

Quaternary structure: multiple polypeptide chains joined together. Not found in all proteins.

I'm particularly interested in knowing if the bolded bits are correct.

Thanks!

I know that you're correct in your descriptions of all of them (except I'm not sure about the bold bits), but I'm not sure about whether there are any ways to word them better


I have a question that's been annoying me for a while. Is the difference between a triglyceride and a phospholipid simply that the phospholipid has a phosphate head as well as a glycerol molecule, while the triglyceride only has a glycerol molecule (and not the phosphate head)? It's been confusing me because some people are saying that a phospholipid has a glycerol molecule, others have said it has a phosphate molecule, and I don't know anymore...
It would be awesome if someone could tell me what a triglyceride is made of, and what a phospholipid is made of.
Thanks so much!!

[pi]

I have a question that's been annoying me for a while. Is the difference between a triglyceride and a phospholipid simply that the phospholipid has a phosphate head as well as a glycerol molecule, while the triglyceride only has a glycerol molecule (and not the phosphate head)? It's been confusing me because some people are saying that a phospholipid has a glycerol molecule, others have said it has a phosphate molecule, and I don't know anymore...
It would be awesome if someone could tell me what a triglyceride is made of, and what a phospholipid is made of.
Thanks so much!!

Phospholipids also have a glycerol but only have TWO fatty acids along with a cheeky phosphate group (hence the name), whilst triglycerides have a glycerol group and have THREE fatty acids (also, hence the name).

[TheAspiringDoc]

Phospholipids also have a glycerol but only have TWO fatty acids along with a cheeky phosphate group (hence the name), whilst triglycerides have a glycerol group and have THREE fatty acids (also, hence the name).

plus don't forget the organic group up the head end of the phospholipid (most commonly choline)

[TheAspiringDoc]

From Checkpoints QuizMeMore:

All enzymes:
A) Are made of the same amino acids
B) Contain a non-protein co-factor such as zinc or iron
C) Are proteins
D) Have the same shape

Would love it if someone could help?

[sunshine98]

From Checkpoints QuizMeMore:

Would love it if someone could help?

C, they are all proteins.
Not A cause if they were made of the same amino acids they would have the same structure and  technically be the same enzymes. Then, all enzymes would be the same . Not D cause  of similar reasons as to why its not A. if they had the same shape there would only be one type of enzymes which would only be able to catalyse one type of reaction (lock and key model etc) . If this were the case , we would die.  Not B cause they don't all have/need  co factors.

[sunshine98]

Some bits of this may be a little above VCE level

Hey so can someone confirm if my understanding of protein structures is correct? (and also I'd greatly appreciate any feedback on my wording)

Primary structure: specific sequence of amino acids

Secondary structure: coiled or pleated structure within polypeptide chain caused by interactions between the backbones (i.e. non-variable part) of amino acids. Includes alpha-helices and beta-pleated sheets.

Tertiary structure: overall three-dimensional structures of the polypeptide chain (composed of secondary structures) caused by interactions between the R-groups (i.e. variable regions) of amino acids.

Quaternary structure: multiple polypeptide chains joined together. Not found in all proteins.

I'm particularly interested in knowing if the bolded bits are correct.

Thanks!

All the bolded is not apart of VCE Bio but did learn in chem and afaik the bolded bit is correct.

[StupidProdigy]

From Checkpoints QuizMeMore:

Would love it if someone could help?

My bio is rusty. So eliminate a immediately because if they had the same structure then all enzymes would more or less have the same function, which they don't. Same logic with D, there are lots of enzyme types and hence lots of different shapes, forms and structures. Option C I eliminated because I remember hearing that not all enzymes are proteins, this is a common misconception apparently. Look into the enzyme RNAse I think its called, apparently that isn't a protein (this may be false...my memory is rusty haha). So from here it must be B (I hope... )

Edit: dang it, clashing answers with sunshine...I will admit B doesn't look correct, it's quite an 'absolute' kind of answer and I didn't think it was correct to start with..bad question I think

[TheAspiringDoc]

C, they are all proteins.
Not A cause if they were made of the same amino acids they would have the same structure and  technically be the same enzymes. Then, all enzymes would be the same . Not D cause  of similar reasons as to why its not A. if they had the same shape there would only be one type of enzymes which would only be able to catalyse one type of reaction (lock and key model etc) . If this were the case , we would die.  Not B cause they don't all have/need  co factors.

But..

Spoiler

Enzymes don't have to be proteins...

I would say "macromolecules" instead of proteins in my definition.

And yeeah, a ribozyme is defined as 'a RNA enzyme' so..

My bio is rusty. So eliminate a immediately because if they had the same structure then all enzymes would more or less have the same function, which they don't. Same logic with D, there are lots of enzyme types and hence lots of different shapes, forms and structures. Option C I eliminated because I remember hearing that not all enzymes are proteins, this is a common misconception apparently. Look into the enzyme RNAse I think its called, apparently that isn't a protein (this may be false...my memory is rusty haha). So from here it must be B (I hope... )

Edit: dang it, clashing answers with sunshine...I will admit B doesn't look correct, it's quite an 'absolute' kind of answer and I didn't think it was correct to start with..bad question I think

EDIT: yes I agree bad question. The all at the start was always going to be a problem..