Post by: Martoman on May 28, 2010, 06:02:57 pm
How many sugar-phosphate bonds are formed when 6 nucleotides join to form a single strand of DNA?
I drew it out but got 10 links, as for 2 sugars there were 2 links, 3 there were 4, 4 -> 6 5 - > 8 and 6 -> 10.
This was drawn like:
S
|
P - S
|
P - S
So the amount of bonds for 3 as you can see is 4? Is this right?
I also do not get this idea of hydrolyzing DNA. Like for example:
A particular gene consists of 100 nucleotides. How many molecules of water are needed to completely hydrolyze the gene? What bond are we hydrolyzing btw?
Post by: Studyinghard on May 28, 2010, 06:21:19 pm
you can hydrolyse the phosphate-sugar bonds in the nucleotide. When the phosphate and sugar bond they eliminate water so to reverse the process you hydrolyse with water.
Post by: m@tty on May 28, 2010, 06:22:07 pm
Quote
How many sugar-phosphate bonds are formed when 6 nucleotides join to form a single strand of DNA?
With this there are only 5. The nucleotides are already formed, hence for n nucleotides to join there must be n-1 bonds formed..
Quote
Minimum number of nucleotides needed to code for a protein segment with amino acids. This is just 3n yes?
Yes, as far as I know there are 3 required per amino acid.
Post by: Studyinghard on May 28, 2010, 06:23:40 pm
QuoteHow many sugar-phosphate bonds are formed when 6 nucleotides join to form a single strand of DNA?
With this there are only 5. The nucleotides are already formed, hence for n nucleotides to join there must be n-1 bonds formed..
but one sugar connects to 2 phosphate molecules.
Post by: simonhu81292 on May 28, 2010, 06:25:10 pm
bad wording . . .
Post by: Martoman on May 28, 2010, 06:28:18 pm
Post by: m@tty on May 28, 2010, 06:31:32 pm
QuoteHow many sugar-phosphate bonds are formed when 6 nucleotides join to form a single strand of DNA?
With this there are only 5. The nucleotides are already formed, hence for n nucleotides to join there must be n-1 bonds formed..
but one sugar connects to 2 phosphate molecules.
But one of these bonds are already formed. 6 nucleotides are sitting there, the deoxyribose sugar is already bonded to phosphate in each. Hence when they bond together there is only 1 bond required for 2 nucleotides, 2 for 3 .... 5 for 6.
Base-S-P (<-- nucleotide; already formed)
|
Base-S-P (<-- nucleotide; already formed)
etc.
The red bond is the only one required to form..
EDIT:
If so then sure there will be 5. This was from a NEAP test so this really *shouldn't* happen, otherwise the way I was doing it is right?
Why shouldn't it happen ??
Anyway, it clearly stated that nucleotides were bonding together, not deoxyribose, phosphate and nitrogeneous bases bonding to form a strand of DNA consisting of 6 nucleotides.
Post by: Martoman on May 28, 2010, 06:33:57 pm
Post by: m@tty on May 28, 2010, 06:59:04 pm
Quote
Otherwise the way I was doing it is right?
Depends what was asked.
If it asked "How many sugar-phosphate bonds are formed when the makings of 6 nucleotides join to form a single strand of DNA?" Then yes.
Post by: stonecold on May 28, 2010, 07:18:35 pm
A particular gene consists of 100 nucleotides. How many molecules of water are needed to completely hydrolyze the gene? What bond are we hydrolyzing btw?
Isn't it just 99?
By hydrolyse the gene I assume it means breaking it back down into nucleotides...
Post by: fady_22 on May 28, 2010, 07:22:22 pm
A particular gene consists of 100 nucleotides. How many molecules of water are needed to completely hydrolyze the gene? What bond are we hydrolyzing btw?
Isn't it just 99?
You are hydrolysing the phosphodiester bonds between the nucleotides. You are not, however, hydrolysing the bonds in the nucleotides themselves. Since in a gene with 100 nucleotides (I'm assuming this means both strands, not not 100 nucleotides on each strand), you'll need 98 molecules to hydrolyse 98 bonds between phosphate and deoxyribose.
Post by: stonecold on May 28, 2010, 07:24:03 pm
49 for the 50 nucleotides on each strand?
Post by: fady_22 on May 28, 2010, 07:24:47 pm
^ In that case fady, wouldn't it be 98?
49 for the 50 nucleotides on each strand?
Yep, you're right. :)
Post by: stonecold on May 28, 2010, 07:33:08 pm
i think the question is asking for the phosphodiester bonds ...
bad wording . . .
if that was the case, then would the answer be 11?
Post by: Martoman on May 28, 2010, 08:06:21 pm
It agree its 99. Then a further 100*2 are needed to break bonds between the nucleotide.
So this means 99 + 100*2 = 299.
I'm fairly sure this is right.
Post by: shinny on May 28, 2010, 08:09:26 pm
Um for the hydrolysing FULLY one.
It agree its 99. Then a further 100*2 are needed to break bonds between the nucleotide.
So this means 99 + 100*2 = 299.
I'm fairly sure this is right.
You're only hydrolysing the bonds between the nucleotides; not within the nucleotides.
Post by: Martoman on May 28, 2010, 08:10:22 pm
Post by: stonecold on May 28, 2010, 08:15:55 pm
Anyway, I wouldn't stress. It's far too ambiguous...there are many answers depending on how the question is interpreted.
Post by: Martoman on May 28, 2010, 08:18:10 pm
Post by: kenhung123 on May 28, 2010, 08:29:17 pm
Post by: Martoman on May 28, 2010, 08:45:09 pm
Post by: physics on May 28, 2010, 10:07:27 pm
Post by: Mao on May 29, 2010, 02:13:38 am
Post by: stonecold on May 29, 2010, 10:10:31 pm
50 on each strand, so 49 x 2 water molecules to break down into individual nucleotides. Then 2x100 molecules to fully hydrolyse into separate phosphate, sugar and base molecules, so the answer could also be 298.
I don't think VCAA are very interested in this as a means of testing. In the 2008 sample exam, there is just a drawing of a double stranded DNA fragment with 9 nucleotide pairs, and they ask how many water molecules are required to break it down into its constituent nucleotides. Answer is just 16.
On a side note, it may be worth getting familiar with the H-bonding between base pairs:
http://en.wikipedia.org/wiki/DNA#Base_pairing
Post by: m@tty on May 29, 2010, 11:55:20 pm
For what it's worth, I definitely agree with matty for the polymerization question, and am leaning towards martoman (299 bonds severed) for the hydrolysis question.
Is a gene single stranded?
Post by: Mao on May 30, 2010, 02:29:06 pm
For what it's worth, I definitely agree with matty for the polymerization question, and am leaning towards martoman (299 bonds severed) for the hydrolysis question.
Is a gene single stranded?
that is debatable. I'll leave it to a biochemist to answer this, I personally have no idea.
Post by: stonecold on May 30, 2010, 08:30:17 pm
I think this is right, if not, my teacher really needs to get her shit together.
Anyway just remember, start from the top, and work your way left. A and T have two polar sites, whilst C and G have 3. Any group with H in it is always +, whilst O and N on their own are -
Hope this helps, because I was really struggling to match up the molecules but with this it seems a lot easier. :)
Post by: Martoman on May 30, 2010, 08:41:42 pm
And to get them to bond you have to make them go one rotation to the right then a reflection about the "y-axis" (lol methods).
Post by: stonecold on May 30, 2010, 08:49:47 pm
And umm, y-axis or x-axis?
Post by: Martoman on May 30, 2010, 08:58:16 pm
So you rotate the thing one thing to the right then flip it from left to right. Then you have to *grab* it from its place and place it to the left of its purine base. This makes its bonding easy to see.
Post by: iffets12345 on May 31, 2010, 09:50:31 pm
I usually remember these by the fact that the letters "CG" is *curvy* like the number 3 and AT are the other number: 2.
If anyones watched GATTACA, I just thought the AT go together and presto!
Post by: azn_dj on May 31, 2010, 10:21:54 pm
If anyones watched GATTACA, I just thought the AT go together and presto!*likes*
My method was G and C are 3.
Post by: m@tty on May 31, 2010, 10:25:39 pm
Nah, I just remember... somehow... read it a few times, then remembered.
Post by: iffets12345 on May 31, 2010, 11:04:49 pm
Post by: Martoman on June 01, 2010, 05:54:49 pm
Its called synesthesia i think.
Post by: stonecold on June 01, 2010, 06:12:55 pm
Just remember that you CUT yourself on a glass pyramid
C - cytosine
U - uracil
T - thymine
The rest are then obviously purine. :D
Courtesy of Douchy's biology podcast
Post by: naved_s9994 on June 01, 2010, 06:17:27 pm
Just for anyone who doesn't do Biology and want's a super schmik way to remember what the purine and pyramidine bases are....
Just remember that you CUT yourself on a glass pyramid
C - cytosine
U - uracil
T - thymine
The rest are then obviously purine. :D
Courtesy of Douchy's biology podcast
LOL. Even though Ive commited that to memory, I absolutely LOVE that!
CUT - Pyramid :P
Post by: shinny on June 01, 2010, 06:30:20 pm
Post by: m@tty on June 01, 2010, 06:31:55 pm
Post by: kyzoo on June 01, 2010, 08:39:13 pm
Post by: iffets12345 on June 01, 2010, 11:41:13 pm
You may be like me? Do you see colors and taste music? When you do math in your head do you like *see* an answer without thinking?Yes, synesthesia I think, your symptoms are kind of similar but not the taste part. I see answers and things in my mind. Things have "feels" to them, like words and colours and numbers. weird :)
Its called synesthesia i think.
Post by: Cuntryboner on June 02, 2010, 12:05:56 am
Okay, thought I'd upload this. It is just the bases from the data book, but I put the polar charges on them just in case we have to draw the hydrogen-bonding between two base pairs.Yeah I did the same thing, CUT mnenomic also is rad... my teacher introduced FON for hydrogen bonding and OIL RIG CAT for redox ...
I think this is right, if not, my teacher really needs to get her shit together.
Anyway just remember, start from the top, and work your way left. A and T have two polar sites, whilst C and G have 3. Any group with H in it is always +, whilst O and N on their own are -
Hope this helps, because I was really struggling to match up the molecules but with this it seems a lot easier. :)
Post by: olly_s15 on June 02, 2010, 12:24:50 am
the red cat ____ an ox
"red" meaning reduction at "cat" meaning cathode and "ox" meaning oxidation at "an" meaning anode
obviously we came up with some interesting ways to remember it
Post by: stonecold on June 02, 2010, 08:56:32 am
Also, isn't nitrogen totally dependent on the formula.
i.e. NO3- Nitrogen is +5
NH4+ Nitrogen is -3
Post by: stonecold on June 02, 2010, 10:50:09 am
All of the other charges just come from the group number lol...
Post by: |ll|lll| on June 02, 2010, 02:11:00 pm
(There are also a few other compounds where oxidation number is sometimes not a whole number or when the oxidation number is not that valence charge, such as HClO <-- the oxidation no. of Cl is actually +1 and not -1. It's actually very unstable.)
As for the first compound, N could be +3. (Nitrogen can lose up to 5 electrons and gain up to 3 electrons.) Assuming F and Cl to have an oxidation no. of -1, O to have an oxidation of -2 and H to have an oxidation no. of +1. But then again, I could be wrong, because H could be -1 and so may differ for other elements. You may want to draw out and try to guess-and-check. :P
Post by: stonecold on June 02, 2010, 02:14:04 pm
Just follow FHONCl haha.
H is +1, O is -2, so Cl has to be + 1 :)
Post by: Martoman on June 02, 2010, 02:52:09 pm
I'm pretty sure for FO2, the oxidation state of oxygen is +0.5, though I have no idea how it gains HALF an electron...
oxidation numbers don't mean anything by themselves.
If there is a change then it means something. That change could be anything, so long as you can distinguish it as +ve and -ve.
Post by: Mao on June 02, 2010, 10:31:52 pm
Oxidation numbers, in reality, only have meaning if there is a physical structure. Later on this concept will be replaced with 'dipole moments'.
Post by: kenhung123 on June 03, 2010, 04:11:08 pm
Post by: Martoman on June 03, 2010, 05:01:52 pm