VCE Biology Question Thread

[TheAspiringDoc]

Which organelles do we need to know their functions of thoroughly? Thanks

Nucleus is the control centre of the cell, it contains the nucleolus which contains Proteins and DNA (deoxyribnucleic acid)
The Golgi apparatus is the Like the post office of a cell because it packages proteins which will later be transported by the ER.
the Ribosomes synthesise proteins.
Mitochondria produce energy for the cell by converting ATP (Tri phosphate) into ADP (Di phosphate) + energy
The vacuole contains water and some enzymes and can isolate treating compounds and waste products.
The cytosol is the fluid that holds the organelles.
Lysosomes recycle old organelles and waste.
Chloroplasts are found in plant cells, they contain the pigment chlorophyll and take energy from the sun in order to photosynthesise.
The Endoplasmic Reticulum (ER) is like a road for transporting things (particularly proteins) around the cell. Rough ER is called so because it is studded with Ribosomes.
It is also worth learning the difference between animal and plant cells and eukaryotic and prokaryotic cells.
I'm not sure all this is right though, just what I remember, so check wikipedia.

[Yacoubb]

Nucleus is the control centre of the cell, it contains the nucleolus which contains Proteins and DNA (deoxyribnucleic acid)
The Golgi apparatus is the Like the post office of a cell because it packages proteins which will later be transported by the ER.
the Ribosomes synthesise proteins.
Mitochondria produce energy for the cell by converting ATP (Tri phosphate) into ADP (Di phosphate) + energy
The vacuole contains water and some enzymes and can isolate treating compounds and waste products.
The cytosol is the fluid that holds the organelles.
Lysosomes recycle old organelles and waste.
Chloroplasts are found in plant cells, they contain the pigment chlorophyll and take energy from the sun in order to photosynthesise.
The Endoplasmic Reticulum (ER) is like a road for transporting things (particularly proteins) around the cell. Rough ER is called so because it is studded with Ribosomes.
It is also worth learning the difference between animal and plant cells and eukaryotic and prokaryotic cells.
I'm not sure all this is right though, just what I remember, so check wikipedia.

You're great at this, but I'll offer some of my tips for fine tuning your answers because that's all you really need!

- don't say mitochondria produce energy because practically, it doesn't. The organelle itself is the site of ATP production. So say that 'mitochondria are the site of aerobic cellular respiration (I.e. ATP production).
- a protein synthesised in the ribosomes attached to the rough enoplasmic reticulum are transported within the cell TO the Golgi complex, and then the vesicle containing the protein or other compound leaves the cell by exocytosis. It isn't golgi complex to rough endoplasmic reticulum. Careful!
- I wouldn't say chloroplasts take energy. I'd say they convert radiant energy to chemical energy stored in sugars. Again, I'm being pedantic, but VCAA is pedantic.

Good work!!

[cosine]

This question is bugging me so hard... I asked my teacher but she went on something else and didnt even answer it -.-

1). Is the plasma membrane 'semi permeable', does this refer to the ACTUAL phospholipids being semi permeable, or the whole membrane in general including the proteins, glycoproteins etc.. Because If it refers to the phospholipids, then the answer would be its semi permeable because due to the hydrophobic region of the fatty acid chains, only certain substances can easily diffuse through the membrane. However, if it refers to the whole structure in general, then it would be because certain substances cannot freely go through because of the phospholipids but also the protein molecules embedded only allow for certain polar molecules or ions to pass through... Haha, confusing I know!

2). We all know the tonicities and the knowledge related to it. BUT, when a red blood cell is placed in a hypertonic solution, we know that the water will diffuse out of the red blood cell because equilibrium needs to be reached. But, say the solute is glucose. So, if there is more glucose in the hypertonic solution, why doesn't the glucose just go down it's concentration gradient and diffuse into the cell via facilitated transport?

Thanks people

[Yacoubb]

This question is bugging me so hard... I asked my teacher but she went on something else and didnt even answer it -.-

1). Is the plasma membrane 'semi permeable', does this refer to the ACTUAL phospholipids being semi permeable, or the whole membrane in general including the proteins, glycoproteins etc.. Because If it refers to the phospholipids, then the answer would be its semi permeable because due to the hydrophobic region of the fatty acid chains, only certain substances can easily diffuse through the membrane. However, if it refers to the whole structure in general, then it would be because certain substances cannot freely go through because of the phospholipids but also the protein molecules embedded only allow for certain polar molecules or ions to pass through... Haha, confusing I know!

2). We all know the tonicities and the knowledge related to it. BUT, when a red blood cell is placed in a hypertonic solution, we know that the water will diffuse out of the red blood cell because equilibrium needs to be reached. But, say the solute is glucose. So, if there is more glucose in the hypertonic solution, why doesn't the glucose just go down it's concentration gradient and diffuse into the cell via facilitated transport?

Thanks people

• The plasma membrane as a whole is selectively permeable. Only selective materials are capable of crossing areas of the membrane - be it the phospholipid bi-layer, allowing tiny OR lipid-soluble molecules to cross, or the protein channels, with passages shaped specifically complementary to the shape of molecules they transport by active transport or facilitated diffusion.
• I'm not too sure about this, but I feel like you're over-thinking it. Perhaps given glucose would travel by facilitated diffusion, and osmosis is easier/quicker, the establishment of water equilibrium would be quicker than the equilibrium of glucose levels.

[cosine]

• The plasma membrane as a whole is selectively permeable. Only selective materials are capable of crossing areas of the membrane - be it the phospholipid bi-layer, allowing tiny OR lipid-soluble molecules to cross, or the protein channels, with passages shaped specifically complementary to the shape of molecules they transport by active transport or facilitated diffusion.
• I'm not too sure about this, but I feel like you're over-thinking it. Perhaps given glucose would travel by facilitated diffusion, and osmosis is easier/quicker, the establishment of water equilibrium would be quicker than the equilibrium of glucose levels.

Thanks so much Yacoubb, that was really helpful!

[Yacoubb]

Thanks so much Yacoubb, that was really helpful!

My pleasure

[vox nihili]

2). We all know the tonicities and the knowledge related to it. BUT, when a red blood cell is placed in a hypertonic solution, we know that the water will diffuse out of the red blood cell because equilibrium needs to be reached. But, say the solute is glucose. So, if there is more glucose in the hypertonic solution, why doesn't the glucose just go down it's concentration gradient and diffuse into the cell via facilitated transport?

Thanks people

Glucose transport is trippy, that's why. That's the short and simple. Yacoubb's right though (as usual)—you're overthinking

[TheAspiringDoc]

Hi,
I'm thinking of making a poster for the wall (fridge or bathroom or bedroom) to help me learn some biology..
Can anyone think of any suggestions of what to put on it?
So far I'm thinking organelles, cell types, enzymes and worded and chemical representations of photosynthesis and cellular respiration...
I'm in year 9 btw.
Thanks!   

[vox nihili]

Hi,
I'm thinking of making a poster for the wall (fridge or bathroom or bedroom) to help me learn some biology..
Can anyone think of any suggestions of what to put on it?
So far I'm thinking organelles, cell types, enzymes and worded and chemical representations of photosynthesis and cellular respiration...
I'm in year 9 btw.
Thanks!   

Just do some general reading. Go nuts on the net and find out some things you want to know about. In year 9, it's much better to try to get interested rather than hard learn everything

[Yacoubb]

Just do some general reading. Go nuts on the net and find out some things you want to know about. In year 9, it's much better to try to get interested rather than hard learn everything

Totally agree!
When I was in year 9 I was infatuated with Biology!! I just read a lot about it, and it was perfect because doing that actually set me up well for VCE Bio! :-)

If you are too functional now, you may burn out so just take it easy! I'm sure you'll do well! Don't worry!!

[TheAspiringDoc]

Totally agree!
When I was in year 9 I was infatuated with Biology!! I just read a lot about it, and it was perfect because doing that actually set me up well for VCE Bio! :-)

If you are too functional now, you may burn out so just take it easy! I'm sure you'll do well! Don't worry!!

ahhh 

[cosine]

Anyone here willing to lend me some tips on how to absolutely demolish biology and score a 50?

I love the subject, voluntarily doing the homework, extra work and questions.. But what does it take to score that big 50, or even 45-50? Realistically, when should I finish the course to do practice exams, etc..!

Thanks

[Yacoubb]

ahhh 

I can definitely understand your passion!!
If you really feed your passion with early readings for pleasure (I read Biology notes like a bed-time story), it'll give you a healthy foundation of what is to come!! 

Anyone here willing to lend me some tips on how to absolutely demolish biology and score a 50?

I love the subject, voluntarily doing the homework, extra work and questions.. But what does it take to score that big 50, or even 45-50? Realistically, when should I finish the course to do practice exams, etc..!

Thanks

I didn't get 50, but I'll give my five cents. Biology is about understanding & not capping your knowledge. Immerse yourself in the topics, because that'll facilitate how you answer application questions in the exam. Furthermore, spend time refining your short answers. This will take practice, but practice makes perfect. Finally, a passion (which you evidently have) is of essence if you want to do well in Bio!!

[Bestie]

I have some questions related to carbohydrates (q1 and 2)

1) how would I explain how the different classes of carbohydrates are related to their function.
I know the different classes are monosaccharides, disaccharides and polysaccharides but I'm not sure how this links with their function? Aren't all their functions the same? To provide energy?

2) devise a simple diagram that compares the structural polysaccharides that make up the cell walls in plants and fungi?
No idea how I would do that....

I have some other questions on lipids

3) triglyceride/triglycerol is the same thing as lipids right?

4) how would I relate the structure of lipid molecules to the function.
I know lipids are glycerol attached to three fatty acids or phosphate group or carbohydrate group but how would I link it to function?

Thanks in advance

[Yacoubb]

I have some questions related to carbohydrates (q1 and 2)

1) how would I explain how the different classes of carbohydrates are related to their function.
I know the different classes are monosaccharides, disaccharides and polysaccharides but I'm not sure how this links with their function? Aren't all their functions the same? To provide energy?

2) devise a simple diagram that compares the structural polysaccharides that make up the cell walls in plants and fungi?
No idea how I would do that....

3) triglyceride/triglycerol is the same thing as lipids right?

Thanks in advance

1. To be honest, you really only need to know about glucose, glycogen, starch and cellulose. General knowledge that carbohydrates are good sources of energy is also beneficial. For the four carbohydrates I listed, the following explanations of functions should suffice:
• Glucose: source of chemical energy for living organisms, broken down in cellular respiration to provide useable (ATP) energy.
• Glycogen: storage of energy in animal cells.
• Starch: storage of energy in plant cells.
• Cellulose: composes the core of plant cell walls, providing added structural support.

2. Well chitin makes up the core of fungi cell walls typically, while cellulose makes up the core of plant cell walls typically. So perhaps draw the structural diagrams of each polysaccharide? Doubt you'd be asked something like this in the exam.

3. Triglycerides fall under the 'lipids' category.