Introduction
In the field of genetics, DNA plays a crucial role in determining the characteristics of living organisms. DNA consists of two complementary strands, each made up of nucleotides. These nucleotides are represented by four different letters: A, T, C, and G. In this article, we will explore the complementary DNA strand to the given sequence 5′-attcggtga-3′.
Understanding DNA Structure
In order to understand the complementary DNA strand, it is important to first comprehend the structure of DNA. DNA is a double helix, where two strands are intertwined to form a twisted ladder-like structure. Each strand is made up of a sequence of nucleotides, with each nucleotide consisting of a sugar, a phosphate group, and a nitrogenous base.
Base Pairing Rule
The base pairing rule states that adenine (A) always pairs with thymine (T) and cytosine (C) always pairs with guanine (G). This rule ensures that the two DNA strands are complementary to each other. Therefore, in order to determine the complementary DNA strand, we need to replace each nucleotide with its corresponding base according to the base pairing rule.
Determining the Complementary DNA Strand
Given the sequence 5′-attcggtga-3′, we can determine its complementary DNA strand by replacing each nucleotide using the base pairing rule.
Step 1: Replacing Adenine (A)
According to the base pairing rule, adenine (A) always pairs with thymine (T). Therefore, we replace each A with T in the given sequence, resulting in 5′-ttaaccact-3′.
Step 2: Replacing Thymine (T)
Since we have already replaced A with T, we need to replace T with A. Hence, the sequence becomes 5′-ttaaccact-3′.
Step 3: Replacing Cytosine (C)
Similarly, cytosine (C) always pairs with guanine (G). Replacing each C with G in the sequence gives us 5′-ttaaccact-3′.
Step 4: Replacing Guanine (G)
Finally, we replace each G with C, resulting in the complementary DNA strand 5′-ttaaccact-3′.
Conclusion
The complementary DNA strand to the given sequence 5′-attcggtga-3′ is 5′-ttaaccact-3′. Understanding the base pairing rule allows us to determine the complementary strand, which is essential in various genetic studies and experiments. By knowing the complementary strand, scientists can analyze and manipulate DNA for a wide range of purposes, such as genetic engineering, disease diagnosis, and forensic investigations.