DNA Base Pairing
There are base pairing rules for writing complimentary DNA strands for a given strand. Write the complimentary DNA strand for each given strand of DNA.C G T A G C G C T A A T T A
T C T T A A A T G A T C G A T C
A A T G A A T A G C T A G C T T
The Correct Answer and Explanation is:
Complimentary DNA Strands
To determine the complementary DNA strand, we follow base pairing rules:
- A (Adenine) pairs with T (Thymine)
- T (Thymine) pairs with A (Adenine)
- C (Cytosine) pairs with G (Guanine)
- G (Guanine) pairs with C (Cytosine)
Now, let’s find the complementary strands:
1. Original Strand:
C G T A G C G C T A A T T A
Complementary Strand:
G C A T C G C G A T T A A T
2. Original Strand:
T C T T A A A T G A T C G A T C
Complementary Strand:
A G A A T T T A C T A G C T A G
3. Original Strand:
A A T G A A T A G C T A G C T T
Complementary Strand:
T T A C T T A T C G A T C G A A
Explanation
DNA, or deoxyribonucleic acid, stores genetic information in the form of a double helix. Each strand is composed of nucleotides, each containing a sugar, a phosphate group, and one of four nitrogenous bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
The structure of DNA relies on specific base pairing rules, first proposed by Erwin Chargaff and later confirmed by James Watson and Francis Crick. These rules ensure that:
- Adenine (A) always pairs with Thymine (T) through two hydrogen bonds, and
- Cytosine (C) always pairs with Guanine (G) through three hydrogen bonds.
This complementarity is crucial during DNA replication. When a DNA molecule is copied, the two strands separate, and new complementary nucleotides are added to each original strand, forming two identical DNA molecules.
In this exercise, each original strand is a single sequence of DNA bases. The task was to determine the complementary strand by applying the base pairing rules one base at a time. For example, if the original base is C, the complementary base is G. If it’s T, it pairs with A, and so on.
This principle of base pairing is fundamental not only to DNA replication but also to processes like transcription (copying DNA to RNA) and various biotechnology applications such as PCR and DNA sequencing.
By understanding how complementary strands are formed, we gain insight into the stability and accuracy of genetic information transfer across generations.
