Problem 94 - Chemistry The Central Science

Question

Can a DNA strand bind to a complementary RNA strand? Explain.

Step-by-Step Solution

Answer

Yes, a DNA strand can bind to a complementary RNA strand due to the formation of hydrogen bonds between their nitrogenous bases. The binding follows the rules of complementary base pairing, with adenine in DNA pairing with uracil in RNA and guanine in DNA pairing with cytosine in RNA. This process is essential for various biological processes, such as transcription.

Step 1: Introduction to DNA and RNA

DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are both nucleic acids and are essential molecules for life. DNA is responsible for storing genetic information, while RNA plays a role in various cellular processes such as protein synthesis, regulation, and expression of genes.

Step 2: Basic Structure

The basic structure of both DNA and RNA consists of a sugar molecule, a phosphate group, and a nitrogenous base. The primary difference between DNA and RNA is the sugar molecule. In DNA, it is deoxyribose, while in RNA, it is ribose.

Step 3: Nitrogenous Bases

DNA has four nitrogenous bases: adenine (A), thymine (T), guanine (G), and cytosine (C). RNA also has four nitrogenous bases: adenine, uracil (U), guanine, and cytosine. The main difference here is that RNA has uracil instead of thymine, which is present in DNA.

Step 4: Complementary Base Pairing

DNA and RNA follow a specific pattern of complementary base pairing. In the case of DNA, adenine always pairs with thymine (A-T), and guanine pairs with cytosine (G-C). In RNA, the pairing is between adenine and uracil (A-U) and guanine and cytosine (G-C).

Step 5: DNA-RNA Binding

Considering the rules of complementary base pairing, a DNA strand can bind to a complementary RNA strand. This happens due to the formation of hydrogen bonds between the nitrogenous bases of both strands. The binding between DNA and RNA follows the same pairing rules: adenine in DNA pairs with uracil in RNA and guanine in DNA pairs with cytosine in RNA. In conclusion, a DNA strand can bind to a complementary RNA strand, and this process plays a crucial role in several biological processes, such as transcription. The binding occurs because of the formation of hydrogen bonds following the rules of complementary base pairing.