URGENT HELP./BIOCHEM

[dddd]

I need answers to those questions...PLS HELP

1)
A solution containing glycogen phosphorylase b (180,000MW), hemoglobin (64,000MW), myoglobin (16,000MW), and DNP-glutamine was applied to an appropriate gel filtration column. The column was eluted with buffer. The four substances eluted in the order (first to last off column)
a) glycogen phosphorylase, hemoglobin, myoglobin, and DNP-glutamine.
b) DNP-glutamine, myoglobin, hemoglobin, and glycogen phosphorylase.
c) DNP-glutamine, hemoglobin, myoglobin, and glycogen phosphorylase.
d) hemoglobin, DNP-glutamine, myoglobin, and glycogen phosphorylase.
e) none of the above orders

2)Which polypeptides will not form an ï?¡-helix?
a) Polylysine at pH 2.
b) Polylysine at pH 12.
c) Polyproline at pH 7.
d) Polyglutamate at pH 2.
e) Two of the above answers are correct
3). “Buffer capacity� (defined as the ability of a buffer to resist a change in pH upon addition or removal of H+ or OH-) depends ...
a) solely on the pH of the buffer.
b) solely on the concentration of the buffer components.
c) solely on the pKa of the buffer conjugate acid.
d) on the pH and on the pKa of the buffer conjugate acid.
e) on the pH, the pKa of the buffer conjugate acid, and the concentration of the buffer components.

[Louise]

I need answers to those questions...PLS HELP

1)
A solution containing glycogen phosphorylase b (180,000MW), hemoglobin (64,000MW), myoglobin (16,000MW), and DNP-glutamine was applied to an appropriate gel filtration column. The column was eluted with buffer. The four substances eluted in the order (first to last off column)
a) glycogen phosphorylase, hemoglobin, myoglobin, and DNP-glutamine.
b) DNP-glutamine, myoglobin, hemoglobin, and glycogen phosphorylase.
c) DNP-glutamine, hemoglobin, myoglobin, and glycogen phosphorylase.
d) hemoglobin, DNP-glutamine, myoglobin, and glycogen phosphorylase.
e) none of the above orders

2)Which polypeptides will not form an ï?¡-helix?
a) Polylysine at pH 2.
b) Polylysine at pH 12.
c) Polyproline at pH 7.
d) Polyglutamate at pH 2.
e) Two of the above answers are correct
3). “Buffer capacity� (defined as the ability of a buffer to resist a change in pH upon addition or removal of H+ or OH-) depends ...
a) solely on the pH of the buffer.
b) solely on the concentration of the buffer components.
c) solely on the pKa of the buffer conjugate acid.
d) on the pH and on the pKa of the buffer conjugate acid.
e) on the pH, the pKa of the buffer conjugate acid, and the concentration of the buffer components.

Hi, the purpose of this forum is to help people do their science fair projects, not answer homework questions or take home tests.
Louise

[deleted-2574]

Hi dddd!

In your question #2, if you supply:
"Which polypeptides will not form an ï?¡-helix?" to answers.com,
you'll get back a direct answer plus a wealth of net resources. You'll still need to do the heavy lifting.

This partial answer is posted so others can chime in.

Notes:

1. The exact wording of your input to answers.com, or any other search engine, may have a big impact on your result. So, some experimentation may be needed.
2. Beware of sites that are just trying to sell you something. In answers.com, these are supposed to br segregated under "Sponsored Links." But, they occasionally leak into "Web Results."

[carolinethorn]

Hi,

To answer question 1 you need to think about how gel filtration chromatography works. Then you can use the size information to get the correct answer. This website has a useful picture on the principle of gel filtration - scroll right down to the bottom.
http://lifesciences.asu.edu/resources/m ... raphy.html

To answer question 2 you need to think about what the properties of an alpha helix are and also what types of amino acids the different answers belong to - ie. are they acidic, basic, neutral etc and what would they be at the pH given in each answer.

To answer question 3 you need to remind yourself about what pH implies about the H+ ions in a solution, also what pKA means and what a "strong acid" or "weak" acid is.

I expect you already have notes on this from whoever set these questions so go back over them paying particular attention to the sections on Acids and pH and amino acids. Also check with online sources or your Biochem text book. If you are still having trouble post back with what you think the answers are and your reasons why and we can help you talk your way through it but as mentioned before - we are not here to do it for you.

-Caroline

[dddd]

Hi i really need your help in answering few of my questions...here are my questions..
1 How do i calculate the ratio of Glycine side chains in the form of -NH3+ ? pka is given to be 9.6 ?

2. what will be the net charge of histadine, isoleucine and Glutamate at pH of 6?

Any help would be appreciated
thanks.

[Louise]

Hi i really need your help in answering few of my questions...here are my questions..
1 How do i calculate the ratio of Glycine side chains in the form of -NH3+ ? pka is given to be 9.6 ?

2. what will be the net charge of histadine, isoleucine and Glutamate at pH of 6?

Any help would be appreciated
thanks.

Once again, this forum is for answering questions about science fair projects, not answering homework qeustions. You should use the advice given to you in the previous replies to your other questions (and you should probably thank the people who helped you!).

These questions are very much like your previous question 2. You need to go back to your notes and read about the pka and amino acids. I imagine either your text book or class handouts contain a table which lists the data you need.

If you don't understand acids or bases or something conceptual such that you cannot understand your class material, then you should ask a question about that so you can try to understand (again, not really the purpose of the forum, but people are pretty willing to help you understand. People are generally not willing to provide answers to straightforward homework questions.). As Caroline said, "If you are still having trouble post back with what you think the answers are and your reasons why and we can help you talk your way through it ..."

Louise