VCE Biology Question Thread

[TheAspiringDoc]

Optical mirrors basically means they have the same molecular formula  () but their structural formula may vary, meaning when you draw the structural composition of the glucose molecules, the placement of a specific OH (hydroxyl) group will differ between the two. You don't need to know anything more, in fact, you don't even need to know difference between alpha and beta glucose in Biology 3/4, but now you do xD

So basically chirality, yeah?

[cosine]

Thanks!

I was sweating about it because it was in the biozone

Could I ask another question?

Using examples, distinguish between inorganic and organic molecules and their general roles in cells

I know that inorganic molecules don't have carbons in them and organic molecules do. But that's just about what I know. Is there a big difference in the role of inorganic vs. organic molecules within cells?

Thanks so much in advance

Yes, organic compounds are composed of carbon atoms, whereas inorganic atoms are not composed of carbon atoms. However, there are some exceptions, such as Carbon Dioxide, although it has a carbon atom, it is not considered as an organic compound.

There is not a MAJOR difference between the function of organic and inorganic compounds, it really just depends on the type of molecules involved. So in my opinion, just ignore the comparison of the functions of organic and inorganic, it really is too broad

[TheAspiringDoc]

Thanks!

I was sweating about it because it was in the biozone

Could I ask another question?

Using examples, distinguish between inorganic and organic molecules and their general roles in cells

I know that inorganic molecules don't have carbons in them and organic molecules do. But that's just about what I know. Is there a big difference in the role of inorganic vs. organic molecules within cells?

Thanks so much in advance

Just thought i should point out that some very simple compounds containing carbon (e.g. CO2) are considered inorganic as well.

[Apink!]

Thanks cosine and the aspiring doc!

[jk006915]

hello everyone 
i'm a newbie here and i'll probably ask more questions especially over the summer holidays.. so please take care of me...haha.
anyways, first question, why are lipids not considered a polymer? i can't find a clear answer. And I know they don't have monomers, but i was taught that fatty acids and glycerol were their subunits. What exactly is the difference between a monomer and a subunit then?

And i know this is kinda stupid, but for example, protein contains C, H, O & N, right? But it also contains S & P sometimes. If I had a question on what elements proteins contains, would I write all of them? Or just say C, H, O & N? 

Thanks in advance

[TheAspiringDoc]

hello everyone 
i'm a newbie here and i'll probably ask more questions especially over the summer holidays.. so please take care of me...haha.
anyways, first question, why are lipids not considered a polymer? i can't find a clear answer. And I know they don't have monomers, but i was taught that fatty acids and glycerol were their subunits. What exactly is the difference between a monomer and a subunit then?

And i know this is kinda stupid, but for example, protein contains C, H, O & N, right? But it also contains S & P sometimes. If I had a question on what elements proteins contains, would I write all of them? Or just say C, H, O & N? 

Thanks in advance

For the second one I'd say "It always contains C, H, O & N, and some proteins also contain S and P"

I'll get back to you on the first question in a minute

[heids]

i'm a newbie here and i'll probably ask more questions especially over the summer holidays.. so please take care of me...haha.
anyways, first question, why are lipids not considered a polymer? i can't find a clear answer. And I know they don't have monomers, but i was taught that fatty acids and glycerol were their subunits. What exactly is the difference between a monomer and a subunit then?

We'll look after you, no fear

Well, a polymer is a chain of repeating subunits - kinda like a necklace, with a string of beads.  But lipids are a bit more like earrings - for instance, triglycerides (fats and oils) have a glycerol backbone and then three fatty acid tails dangling off it.  See how it's not a repeating pattern, a long line (like in proteins, where it's a chain of amino acids, or nucleic acids, where it's a chain of nucleotides)?  --> Not a polymer, and the individual subunits aren't monomers.  That's just how polymer/monomer is defined.

[TheAspiringDoc]

We'll look after you, no fear

Well, a polymer is a chain of repeating subunits - kinda like a necklace, with a string of beads.  But lipids are a bit more like earrings - for instance, triglycerides (fats and oils) have a glycerol backbone and then three fatty acid tails dangling off it.  See how it's not a repeating pattern, a long line (like in proteins, where it's a chain of amino acids, or nucleic acids, where it's a chain of nucleotides)?  --> Not a polymer, and the individual subunits aren't monomers.  That's just how polymer/monomer is defined.

Neat

Is it also relevant that lipids aren't able to be hydrolysed because they are insoluble in water (bar phospolipid heads, right?)?

[The Usual Student]

This thread is neat will be using this a lot !

[heids]

Neat

Is it also relevant that lipids aren't able to be hydrolysed because they are insoluble in water (bar phospolipid heads, right?)?

Umm... I honestly don't know.  I was pretty sure that lipids undergo condensation and hydrolysis reactions to join/break apart the subunits...?  Feel free to dig through Google if you're interested, it's already too complex for VCE level aka 'I am ignorant'

This thread is neat will be using this a lot !

Cool, and welcome on board!  Just a word of warning: never trust me.   Also prepare to get ranted at occasionally for not Googling something first

[Scooby]

Neat

Is it also relevant that lipids aren't able to be hydrolysed because they are insoluble in water (bar phospolipid heads, right?)?

Lipids (namely triglycerides) can definitely be hydrolysed, but in aqueous environments it occurs very slowly in the absence of an emulsifier

[TheAspiringDoc]

Lipids (namely triglycerides) can definitely be hydrolysed, but in aqueous environments it occurs very slowly in the absence of an emulsifier

But doesn't solubility just refer to the breaking down of a biomacromolecule (or chemical, but let's use biologyspeak) through hydrolysis?

Because A+ notes says that fats (i.e. triglycerides) are insoluble in water..

Also, biology peeps check out the hyperlink in my profile thingo - it's jaw droppingly fantastical

[Scooby]

But doesn't solubility just refer to the breaking down of a biomacromolecule (or chemical, but let's use biologyspeak) through hydrolysis?

Because A+ notes says that fats (i.e. triglycerides) are insoluble in water..

Also, biology peeps check out the hyperlink in my profile thingo - it's jaw droppingly fantastical

Not quite. Hydrolysis is the breakdown of an individual molecule/compound into smaller units with the addition of water. Solubility is a measure of how well a particular substance dissolves in a given solvent

[TheAspiringDoc]

Not quite. Hydrolysis is the breakdown of an individual molecule/compound into smaller units with the addition of water. Solubility is a measure of how well a particular substance dissolves in a given solvent

But what does it actually mean to dissolve then..?

Thanks Scooby!

Can some please explain to me, does the term 'amphipathic' refer to proteins, or is it something that concerns polar molecules such as water, or all of them? I've found several different definitions and am a little stumped.

Also, why is it that triglicerydes are used for energy storage and all the rest of it? Like I know it is what's used, but why is it in particular used? Like why not a diglyceride or quadglyceride or something like that?

Thanks

[sunshine98]

But what does it actually mean to dissolve then..?

When a  solute dissolves in a solvent :
-solute particles separate
-solvent particles separate
-solvent and solute bond (only dissolve if the bonds between solute and solvent is stronger than it is between solvent and solute alone) 
^this is like unit 2 chem version of explaining dissolving.
But in regards to biology u just need to know that  'like dissolves like' meaning that polar will only dissolve in polar and non polar in non polar. This is why fats are insoluble in water. Fats are non polar and water is polar. Strong bonds do not form between the two. Polar , however , can dissolve in water because water is polar itself. 

Can some please explain to me, does the term 'amphipathic' refer to proteins, or is it something that concerns polar molecules such as water, or all of them? I've found several different definitions and am a little stumped.

Amphipathic in VCE bio is usually used to describe the phospholipid molecule. Amphipathic refers to the fact that a portion of it is hydrophilic/polar (in regards to the phospholipid the phosphate heads)  and the other portion is hydrophobic/non polar (fatty acid tails) .

Not sure bout your last q.
Hope this helps