What is the structure of DNA and RNA?

DNA and RNA are nucleic acids, but they differ in structure and function.

Structure of DNA (Deoxyribonucleic Acid):

1. Double helix: DNA consists of two strands twisted around each other.
2. Sugar: The sugar in DNA is deoxyribose.
3. Bases: Four nitrogenous bases – Adenine (A), Thymine (T), Guanine (G), Cytosine (C).
   • Base pairing: A pairs with T, G pairs with C via hydrogen bonds.
4. Strand direction: The two strands are antiparallel (one runs 5’→3’, the other 3’→5’).
5. Function: Stores genetic information in cells.

Structure of RNA (Ribonucleic Acid):

1. Single strand: RNA usually exists as a single strand, but it can fold into shapes.
2. Sugar: The sugar in RNA is ribose.
3. Bases: Four nitrogenous bases – Adenine (A), Uracil (U), Guanine (G), Cytosine (C)
   • Uracil (U) replaces Thymine (T) in RNA.
4. Types of RNA:
   • mRNA: Messenger RNA, carries code from DNA to ribosomes
   • tRNA: Transfer RNA, brings amino acids to ribosomes
   • rRNA: Ribosomal RNA, part of ribosome structure
5. Function: Helps in protein synthesis and gene expression.

In short:

• DNA: Double-stranded, deoxyribose sugar, bases A-T and G-C, stores genetic information.
• RNA: Single-stranded, ribose sugar, bases A-U and G-C, helps make proteins.