9. The diagram below represents part of the DNA double helix - VCE - SSCE Chemistry - Question 9 - 2009 - Paper 1
Question 9
9.
The diagram below represents part of the DNA double helix.
A
B
i. Write down the formula of the atom or groups of atoms represented by A and B.
A ____________... show full transcript
Worked Solution & Example Answer:9. The diagram below represents part of the DNA double helix - VCE - SSCE Chemistry - Question 9 - 2009 - Paper 1
Step 1
i. Write down the formula of the atom or groups of atoms represented by A and B.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A: C5H5N (representing the nitrogenous base Adenine)
B: C5H5O (representing the nitrogenous base Thymine)
Step 2
ii. Name the base that is complementary to the base shown.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The base that is complementary to Adenine (A) is Thymine (T).
Step 3
b. Explain why the human viral DNA has a lower melting temperature than the monkey viral DNA.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Human viral DNA has a lower melting temperature because it contains a higher percentage of adenine, which pairs with thymine through two hydrogen bonds. In contrast, guanine pairs with cytosine through three hydrogen bonds, providing greater stability. As a result, the increased proportion of A-T pairs in human viral DNA leads to weaker interactions and a lower melting temperature compared to monkey viral DNA, which has a more balanced A-T and G-C ratio.
