Use the Data Booklet to help you answer this question about DNA - AQA - A-Level Chemistry - Question 9 - 2018 - Paper 2
Question 9
Use the Data Booklet to help you answer this question about DNA.
Figure 2 shows a fragment of a DNA double helix.
The letters A, C, G and T represent the four bases ... show full transcript
Worked Solution & Example Answer:Use the Data Booklet to help you answer this question about DNA - AQA - A-Level Chemistry - Question 9 - 2018 - Paper 2
Step 1
Complete Table 4 to show the correct sequence of bases in the complementary strand represented by the numbers 1 to 5.
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Answer
The complementary bases are:
1
2
3
4
5
T
G
C
A
A
Step 2
Deduce the total number of hydrogen bonds formed between the five bases in each strand.
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Answer
Each base pair forms hydrogen bonds as follows:
A and T form 2 hydrogen bonds.
C and G form 3 hydrogen bonds.
For the sequence:
A to T (2 bonds)
C to G (3 bonds)
Thus, the total number of hydrogen bonds formed between the five bases in each strand is 13.
Tick (✓) 13.
Step 3
Complete the structure to show the nucleotide that contains base A.
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Answer
The structure of the nucleotide that contains base A includes:
A phosphate group attached to the 2-deoxyribose molecule.
Base A represented as A, connected to the 2-deoxyribose.
The full structure will be:
Phosphate → 2-Deoxyribose → A
Refer to the correct positioning and connection in the provided structure.