Problem 2 Taskt The equation to determine the % composition of nucleotides conta

Question

Problem 2 Taskt The equation to determine the % composition of nucleotides containing adenine (dAMP), thymine (dTMP). guanine (dGMP), and cytosine (dCMP) bases in a DNA sample are: % dAMP-50-% dGMP What assumption(s) have you made so that the equations shown above are valid? Task 2: In samples of DNA isolated from two unidentified bacteria, X and Y, dAMP makes up 10% and 27%, respectively, of the total nucleotides. Each DNA contains 100 base pairs (equivalent to 200 nucleotides). / b) Calculate the % composition of dAMP, dTMP, dCMP, and dGMP in each DNA sample c) Calculate the total number of H-bonds between base pairs that are formed in the DNA of bacterium X? d) Does the DNA of bacterium Y have more or less total H-bonds compared to the DNA of bacterium X? Provide your reasoning. e) Which bacterium, X or Y, has a more stabilized DNA?

Explanation / Answer

Task 1: (a): A-T so % dAMP = % dTMP

G-C so %dGMP = % dCMP

If % dAMP = 50 - % dGMP so  % dTMP = 50 - % dGMP OR % dAMP = 50 - % dCMP

So assumptions was made are- (1) dAMP and dTMP were used in equal ratio or percentage. (2) Again dGMP and dCMP were used in equal ratio or percentage. Because Guanine will always attach with Cytocine to form a base pair. (3) % dAMP + % dGMP = 50; So percentage of any nucleotide may vary from 0% to 50%. Exact percentage of all the nucleotides could not be determined from the given equations.

------------------------------------------------------------------------------------------------------------------------

Task 2: for X : dAMP = 10% and for Y: dAMP = 27%

(b) % composition in X: dAMP = dTMP = 10%: total = 20 % and remaining = 80%

so dCMP = dGMP = 40%

% composition in Y: dAMP = dTMP = 27% total = 27*2 = 54 % and remaining = 46%

so dCMP = dGMP = 23%

(c) The GC pair is bound by three hydrogen bonds, while AT pair is bound by two hydrogen bonds.

total number of hydrogen bonds between base pairs of DNA X:

dAMP will be 20 and dTMP will be 20 so hydrogen bond = 20*2 = 40

dGMP will be 80 and dCMP will be 80 so hydrogen bond = 80*3 = 240

total H- bonds=280

(d) Y contains more % of dAMP which form lesser H-bonds. so total number of hydrogen bonds will be lesser in Y than X.

(e) X has more hydrogen number bonds and when hydrogen bond number increases then stability will also be increased. bond formation decreases the potential energy of a system and increases stability of the system. so bacterium X has a more stabilized DNA.  

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.