Stuff on DNA

[Martoman]

Minimum number of nucleotides needed to code for a protein segment with amino acids. This is just 3n yes?

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?

[Studyinghard]

When I did 6 nucleotides I got 11 bonds.

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.

[m@tty]

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..

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.

[Studyinghard]

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..

but one sugar connects to 2 phosphate molecules.

[simonhu81292]

i think the question is asking for the phosphodiester bonds ...
bad wording  . . .

[Martoman]

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?

[m@tty]

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..

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.

[Martoman]

See I thought it meant also count the link between base-S-P

[m@tty]

Nah, those bonds are already there...

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.

[stonecold]

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...

[fady_22]

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.

[stonecold]

^ In that case fady, wouldn't it be 98?

49 for the 50 nucleotides on each strand?

[fady_22]

^ In that case fady, wouldn't it be 98?

49 for the 50 nucleotides on each strand?

Yep, you're right.

[stonecold]

i think the question is asking for the phosphodiester bonds ...
bad wording  . . .

if that was the case, then would the answer be 11?

[Martoman]

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.