Unit 3 - DNA depth?

[luken93]

So I'm going through Unit 3 in the Heinemann book, and it seems a lot of the last 2 chapters are more of a case study than anything else.

Can anyone tell me what we are required to know in the DNA onwards section of the textbook?

Thanks

EDIT: I have found this is the study design, I think it answers my question but if anyone has any other info that'd be great!

• the structure and bonding of DNA and its applications in forensic analysis;
• use of proteins as markers for disease;
• function of organic molecules in the design and synthesis of medicines including the production
of aspirin from salicylic acid.

[Russ]

You don't need to know the exact structure of the bases, but you should know the purine/pyrimidine pairing system (A/T and C/G). You also need to know how DNA forms and the structure (backbone, phosphodiester bonds, H bonds etc.)

Understand what the overall charge is on DNA (and where the charge is) and why this allows electrophoresis to separate and identify DNA fragments. Know which base pairing is more stable and why.

Proteins have four different levels of structure and you need to understand the forces that contribute to each level (covalent, H-bonds etc.)

[luken93]

Thanks a lot, that cuts put some of the crap haha

I've never done biology, but is this some of what you do in it?

[nacho]

Bio would probably help with organic chemistry..however the naming conventions might confuse you lol, it'd overlap around 10% with chem.
I think it's best to know the meaning of DNA.
Deoxy Ribo Nucleic Acid.
understand why it can be an acid, the phosphodiesster linkage and the monomer unit which makes up DNA. Have a look at the Primary Structure, intra and intermolecular forces present and also know the nitrogenous base pairings (the nitrogenous base is attached to the deoxyribose sugar).
Also, try and look at why it is 'Anti-parallel' and not parallel.
That's all i can think of lol, but there's probably more. I don't think you're required to know the structural formula of the nitrogenous bases (have a look, but no need to memorise them as it's in the data-booklet) - you can also see how the bases fit in together.

 :police:

[pi]

I think it's best to know the meaning of DNA.
Deoxy Ribo Nucleic Acid.

'Deoxyribonucleic Acid' actually. Just two words.

And the overlap with bio is great! I barely need to read the DNA chapters

[stonecold]

Early days yet, but you need to be very familiar with DNA at a molecular level.

I don't think you would be asked to draw out a DNA molecule, because it would just get too messy.

However, VCAA expect you to know how everything bonds together between the nitrogenous base, deoxyribose sugar and phosphate group.

Know the intramolecular bonds, as well as the intermolecular forces that hold two strands of DNA together.  This was particularly important on last years exam.  There was an entire question devoted to identifying which atoms or group of atoms on a nucleotide could join to another nucleotide to extend the DNA stand, and another question asking which group of atoms on a nucleotide could form hydrogen bonds with another nucleotide to create double stranded DNA.

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

Also, be sure to know antiparallel structure of DNA, and it is also crucial to know that cytosine-guanine bases will form 3 hydrogen bonds, whereas adenine-thymine bases will only form 2 hydrogen bonds.

So basically a DNA coil consisting of a lot of CG base pairs, will denature at a higher temperature than a DNA coil of the same length, but with fewer CG base pairs.

You have lots of time to learnt this, so don't stress out.

Although it may look a little daunting at first. 

[luken93]

Early days yet, but you need to be very familiar with DNA at a molecular level.

I don't think you would be asked to draw out a DNA molecule, because it would just get too messy.

However, VCAA expect you to know how everything bonds together between the nitrogenous base, deoxyribose sugar and phosphate group.

Know the intramolecular bonds, as well as the intermolecular forces that hold two strands of DNA together.  This was particularly important on last years exam.  There was an entire question devoted to identifying which atoms or group of atoms on a nucleotide could join to another nucleotide to extend the DNA stand, and another question asking which group of atoms on a nucleotide could form hydrogen bonds with another nucleotide to create double stranded DNA.

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

Also, be sure to know antiparallel structure of DNA, and it is also crucial to know that cytosine-guanine bases will form 3 hydrogen bonds, whereas adenine-thymine bases will only form 2 hydrogen bonds.

So basically a DNA coil consisting of a lot of CG base pairs, will denature at a higher temperature than a DNA coil of the same length, but with fewer CG base pairs.

You have lots of time to learnt this, so don't stress out.

Although it may look a little daunting at first. 

Thanks a lot, but a couple of things I just want to clear up

 - I have a diagram + explanation for the bonding, so I feel I have that covered.
 - Uracil WTF? I've only read about the 4 bases being Ademine, Cytosine, Guamine and Thymine, where did/does this one come from?
 - Antiparallel structure - Also haven't heard this term either?

I'm using Heinemann btw, which book did you learn this out of?

Thanks a lot anyway!

[pi]

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

That's how I remember it too!

[Greatness]

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

That's how I remember it too!

I learnt it from Douchy  :angel: Whhatta legend!

- Uracil WTF? I've only read about the 4 bases being Ademine, Cytosine, Guamine and Thymine, where did/does this one come from?
 - Antiparallel structure - Also haven't heard this term either?

Uracil is used instead of Thymine in RNA. So, A, U, G, C for RNA and A, T, G, C for DNA.
Antiparallel describes how when the two strands of DNA are joined together, they are ultimately running in opposite dircetions. One strand runs in the 5'-3' direction whilst the other runs 3'-5' (The phosphate group is the 5' end and hydroxy group 3' end) Hydrogen bonds hold these DNA strands together forming a helical structure.

Moderator action: removed real name, sorry for the inconvenience

[luken93]

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

That's how I remember it too!

I learnt it from Douchy  :angel: Whhatta legend!

- Uracil WTF? I've only read about the 4 bases being Ademine, Cytosine, Guamine and Thymine, where did/does this one come from?
 - Antiparallel structure - Also haven't heard this term either?

Uracil is used instead of Thymine in RNA. So, A, U, G, C for RNA and A, T, G, C for DNA.
Antiparallel describes how when the two strands of DNA are joined together, they are ultimately running in opposite dircetions. One strand runs in the 5'-3' direction whilst the other runs 3'-5' (The phosphate group is the 5' end and hydroxy group 3' end) Hydrogen bonds hold these DNA strands together forming a helical structure.

Aha, so I wasn't out of the loop haha
Thanks for clearing that up

Moderator action: removed real name, sorry for the inconvenience

[Russ]

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

That's how I remember it too!

You know you're old when you were never taught any of these fancy memory tricks

Moderator action: removed real name, sorry for the inconvenience

[luken93]

Ok, another question...

PolyAspirin, Penicilin or Developing New Drugs?

Yay/Nay?

[Mao]

Just would like to mention you also need to know polymerase chain reaction and gel electrophoresis, both used in forensic studies.

For drug design, understand that shape is the important factor (fits in receptor, etc). Understand what rational drug design is. Understand the synthesis steps of aspirin. Identify similarities between aspirin and other substitute drugs (paracetamol, iburofen). Don't need to look at synthesis of other specific drugs.

[luken93]

Just would like to mention you also need to know polymerase chain reaction and gel electrophoresis, both used in forensic studies.

For drug design, understand that shape is the important factor (fits in receptor, etc). Understand what rational drug design is. Understand the synthesis steps of aspirin. Identify similarities between aspirin and other substitute drugs (paracetamol, iburofen). Don't need to look at synthesis of other specific drugs.

Yep got all of that apart from
 - Rational Drug Design?
 - Similarities of Aspirin + Ibuprofen, do you mean in terms of structure/bonding?

Thanks a lot, it seems I've got DNA all worked out now

[stonecold]

Remember that you CUT youself on a glass pyramid  (therefore cytosine, uracil and thymine are pyramidines)
That obviously leaves you with the purines, adenine and guanine.

That's how I remember it too!

You know you're old when you were never taught any of these fancy memory tricks

Oh yeah!  2 years makes one hell of a difference haha.

It has evolved so much since you finished. 

Just would like to mention you also need to know polymerase chain reaction and gel electrophoresis, both used in forensic studies.

For drug design, understand that shape is the important factor (fits in receptor, etc). Understand what rational drug design is. Understand the synthesis steps of aspirin. Identify similarities between aspirin and other substitute drugs (paracetamol, iburofen). Don't need to look at synthesis of other specific drugs.

Yep got all of that apart from
 - Rational Drug Design?
 - Similarities of Aspirin + Ibuprofen, do you mean in terms of structure/bonding?

Thanks a lot, it seems I've got DNA all worked out now

Rational drug design may be worth knowing, but IIRC, I thought that was more of a bio thing.  Just make sure you know how drugs are created to fit the active site of a specific enzyme, inhibiting its function.

And just focus on Asprin, I don't even think that other one is on the course.

Moderator action: removed real name, sorry for the inconvenience