Are the DNA template strand and the mRNA sequences similar, or complementary?
Are the DNA coding strand and the mRNA sequences similar, or complementary?
Are the DNA template and the DNA coding strand sequences similar, or complementary?
The DNA template strand and the mRNA sequences are complementary to each other.
To understand why they are complementary, we need to understand the process of transcription. During transcription, an enzyme called RNA polymerase synthesizes mRNA using one strand of DNA as a template. This strand is known as the DNA template strand.
In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). During transcription, however, thymine is replaced by uracil (U) in mRNA. So, in mRNA, adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G).
For example, if the DNA template strand has the sequence 5'-A-T-C-G-A-3', the corresponding mRNA sequence would be 5'-U-A-G-C-U-3'. As you can see, the mRNA sequence is complementary to the DNA template strand.
On the other hand, the DNA coding strand is similar but not complementary to the mRNA sequence. The DNA coding strand has the same sequence as the mRNA, except that it has thymine instead of uracil. So, if the DNA template strand has the sequence 5'-A-T-C-G-A-3', the DNA coding strand would have the sequence 5'-T-A-G-C-T-3'. Therefore, the DNA coding strand and the mRNA sequence are similar but not complementary.
Lastly, the DNA template strand and the DNA coding strand are complementary to each other. They have opposite sequences. So, if the DNA template strand has the sequence 5'-A-T-C-G-A-3', the DNA coding strand would have the sequence 5'-T-A-G-C-T-3'. The two strands of DNA are complementary because they can base-pair with each other through hydrogen bonds.