Psyxwar's Biology 3/4 Question Thread

[curry_bro]

That zwitterion concept is mostly explored in Chemistry 3/4. As curry_bro says, won't need to go into those specifics for Bio 3/4.

For Biology, it's also important to know that protein structure can be affected by pH, because some of the amino acids in the sequence will donate/accept protons with their R-Variable group.

This. +1. just know that fluctuations in pH result in denaturation of protein structure due to the ionisation and deionisation of parts of amino acid chain. This causes certain ionic bonds to break and others to reform within peptide, causing for a conformational change of shape. A change of shape typically results in a change of function in proteins blah blah (be more specific though. if question is about an enzyme, mention how the change of shape may prevent lock and key mechnisms
This is literally all you need to know in terms of how pH effects proteins. 

[psyxwar]

This. +1. just know that fluctuations in pH result in denaturation of protein structure due to the ionisation and deionisation of parts of amino acid chain. This causes certain ionic bonds to break and others to reform within peptide, causing for a conformational change of shape. A change of shape typically results in a change of function in proteins blah blah (be more specific though. if question is about an enzyme, mention how the change of shape may prevent lock and key mechnisms
This is literally all you need to know in terms of how pH effects proteins.

Alright cheers. Yeah I'll just focus on the stuff in the study design now, thanks.

What is the definition for an oligosaccharide? I've been getting a variety of definitions (2-6 monosaccharide units, 2-10, 3-10). Also, are oligosaccharides classified under polysaccharides?

[pi]

What is the definition for an oligosaccharide? I've been getting a variety of definitions (2-6 monosaccharide units, 2-10, 3-10). Also, are oligosaccharides classified under polysaccharides?

It's just a small polysaccharide No need to know anything about them, but Id say 2-10 monosaccharide in length if you were curious

[Stick]

Alright cheers. Yeah I'll just focus on the stuff in the study design now, thanks.

What is the definition for an oligosaccharide? I've been getting a variety of definitions (2-6 monosaccharide units, 2-10, 3-10). Also, are oligosaccharides classified under polysaccharides?

I think monosaccharide (one unit), disaccharide (two units) and polysaccharide (more than two units) with a couple of specific examples should be enough.

[curry_bro]

oligosacharides are covered in first year uni, and are typically components of adhesive proteioglycans on cell surfaces.  im sure u can think of examples of all the other carbs. if not, here you are:
These are set out in the following format

carbohydrate type = example (briefly explained function)

monosaccharides = lactose in milk (energy transport to young)
disaccharides = sucrose in plant phloem (energy transport to other locations of organism)
polysaccharides = starch in plants (energy storage for cellular metabolism)

[Stick]

Lactose is not a monosaccharide. It is a disaccharide consisting of glucose and galactose. A good example of a monosaccharide is good old glucose.

[curry_bro]

hahah its been a while hahaha trust me people, u cant afford to make mistakes like the one i just made in year 12! hahah

[psyxwar]

It's just a small polysaccharide No need to know anything about them, but Id say 2-10 monosaccharide in length if you were curious

Thanks!

oligosacharides are covered in first year uni, and are typically components of adhesive proteioglycans on cell surfaces.  im sure u can think of examples of all the other carbs. if not, here you are:
These are set out in the following format

carbohydrate type = example (briefly explained function)

monosaccharides = lactose in milk (energy transport to young)
disaccharides = sucrose in plant phloem (energy transport to other locations of organism)
polysaccharides = starch in plants (energy storage for cellular metabolism)

Yup, have this all covered. Thanks.

Lactose is not a monosaccharide. It is a disaccharide consisting of glucose and galactose. A good example of a monosaccharide is good old glucose.

Do we actually need to know about lactose and galactose? I mean I've seen them mentioned here and there, but never in any real depth (in the textbooks at least).

[Stick]

Lactose is a good example of a disaccharide so if you decide to use it as an example, it may be useful to know its building blocks. Otherwise, not really.

[curry_bro]

u may have to know it if you get a question about galactosaemia or lactose intolerance on the exam. u wouldnt want to mix the two of them up! (dont bother learning these two conditions now, just take it slow for now - maybe do some light reading of the two conditions in jan?)

[psyxwar]

Yup thanks, I'll keep those in mind. I guess there's no harm in reading up on them.

Do we need to (or I guess, should we?) know about post translational modification in much depth? For example, terms like glycosylation?

[pi]

Do we need to (or I guess, should we?) know about post translational modification in much depth? For example, terms like glycosylation?

Not in much depth at all, just know it happens.

[curry_bro]

Not in much depth at all, just know it happens.

and that it happens in the rough endoplasmic reticulum (never write ER... EVER) and the golgi complex/body/apparatus

[Shenz0r]

Do we actually need to know about lactose and galactose? I mean I've seen them mentioned here and there, but never in any real depth (in the textbooks at least).

It would be good help knowing the monosaccharides, disaccharides, and polysaccharides that VCAA use most often.

Monosaccharides:
Glucose
Fructose
Galactose

Disaccharides:
Maltose (multiple Glucoses)
Lactose (from Galactose)
Sucrose (Fructose + Glucose)

Polysaccharides:
Glycogen (very branched, used as short-term energy storage in animals. Might help to ask yourself: Why does the amount of branching make it a good source of energy in the short-term?)
Starch (not very branched, used as energy-storage in plants. So, why do plants use a polysaccharide that's not really branched?)
Cellulose (used as structural support in plants)

EDIT: You won't need to know what the monosaccharides and disaccharides actually look like. But you should know the structure of the polysaccharides.

[curry_bro]

thats about all you need for carbs (thanks Shenz0r!) you wont ever need to know the chemical structure of any carb, but you should know the 'golden ratio'!
 C(1):H(2):0(1)