What Biochemical Changes Occur with pH Shifts and Nucleotide Composition?

[nemzy]

which of the following will most likely be disrupted by a change in pH?

1) hydrogen bonding
2) ionic bonding
3) hydrophobic interactions
4) disulfide bonds
5) neither

-I'm pretty sure its not 1) and 2) since changing the pH won't affect the electronegativity of an atom...Pretty sure that its not disulfide bonds either, so from that I am guessing that its hydrophobic interactions..am i right? or is my concept wrong?

A nucleotide containing a purine, ribose, and a phosphate group could be a building block for?

a) dna
b) mRna
c) tRna
d) rRna
e) b,c,d

-Ok it is NOT A for sure, so I am assuming that a nucleotide contaning a purine, ribose, and phosphate group could be a building block for all b,c,d...am i right ? or am i missing an important concept?

A DNA molecule with 5'ATCGTAC3' = 3'TAGCATG5' right?

If one thousaidn glucose molecues arrive in a cell, and the 1000 glucose molecules join together into a starch molecue, what changes occurred with the synthesis of the starch molecule?

-well this is an anabolic pathway since we are building something small into something bigger. So entropy decreases, since this is a non-spontaneous system. However, does the entropy of the universe decrease, or the entropy of the cell decrease?

Dehydration syntehisis will decrease entropy within a system right? since its the formation of smaller molecules into bigger ones?

 

[iansmith]

A nucleotide containing a purine, ribose, and a phosphate group could be a building block for?

a) dna
b) mRna
c) tRna
d) rRna
e) b,c,d

-Ok it is NOT A for sure, so I am assuming that a nucleotide contaning a purine, ribose, and phosphate group could be a building block for all b,c,d...am i right ? or am i missing an important concept?

You are right it is not A. Ribose is in all the type of RNA. rRNA requires some protein component. tRNA also require an amino acid to be complete. Although, C and D would be incomplete, they, however, only ask for building block, and E is the answer

A DNA molecule with 5'ATCGTAC3' = 3'TAGCATG5' right?

It is right but you should put in 5' to 3'
5' GTACGAT 3'

 

[ravenprp]

1) Hydrophobic interactions will most likely be disrupted by a change in pH. This is because hydrophobic interactions rely on the balance of polar and nonpolar interactions, which can be affected by changes in pH. When the pH changes, the charge distribution of molecules can also change, altering the strength of hydrophobic interactions.

2) A nucleotide containing a purine, ribose, and a phosphate group could be a building block for all b, c, and d (mRNA, tRNA, and rRNA). This is because all three types of RNA contain nucleotides with these components, which are necessary for their functions in protein synthesis.

3) Yes, the DNA molecule with 5'ATCGTAC3' = 3'TAGCATG5' is correct. This is because the complementary base pairing rules state that adenine pairs with thymine and guanine pairs with cytosine, and the strands of DNA run antiparallel to each other.

4) The synthesis of the starch molecule involved a decrease in entropy within the cell. This is because the cell had to use energy to bring together 1000 glucose molecules and form a larger molecule, which is a more ordered state. However, the overall entropy of the universe may have increased due to the production of heat during the synthesis process.