| Criteria | Deoxyribonucleotides (dNTPs) | Ribonucleotides (NTPs) | Remarks |
| Definition | Monomeric units of DNA, consisting of a nitrogenous base, deoxyribose sugar, and phosphate group | Monomeric units of RNA, consisting of a nitrogenous base, ribose sugar, and phosphate group | Both serve as the building blocks of nucleic acids but differ chemically and functionally. |
| Sugar Component | 2′-Deoxyribose (lacks hydroxyl group at 2′ carbon) | Ribose (has a hydroxyl group at 2′ carbon) | The presence or absence of the 2′-OH group is a key chemical distinction affecting stability and structure. |
| Hydroxyl Group at 2′ Carbon | Absent | Present | The 2′-OH in ribose makes RNA more reactive and less stable compared to DNA. |
| Nitrogenous Bases | Adenine (A), Guanine (G), Cytosine (C), Thymine (T) | Adenine (A), Guanine (G), Cytosine (C), Uracil (U) | Thymine in DNA is replaced by uracil in RNA. |
| Abbreviation | dATP, dTTP, dGTP, dCTP | ATP, UTP, GTP, CTP | “d” denotes deoxy; no “d” in ribonucleotides. |
| Role in Nucleic Acid | Incorporated into DNA strands during replication | Incorporated into RNA strands during transcription | DNA uses deoxyribonucleotides; RNA uses ribonucleotides exclusively. |
| Stability | More stable due to absence of 2′-OH | Less stable; prone to hydrolysis due to 2′-OH | DNA’s chemical stability is suited for long-term genetic storage. |
| Function in Cells | DNA replication, repair, and long-term information storage | Transcription, protein synthesis (via mRNA, tRNA, rRNA), signaling (e.g., cAMP) | Ribonucleotides have broader roles, including catalysis and regulation. |
| Structural Role | Forms double-stranded helical DNA | Forms single-stranded RNA (can fold into complex secondary/tertiary structures) | RNA’s flexible structure allows diverse functions; DNA is mainly storage-oriented. |
| Involvement in Energy Transfer | Rarely (except dATP in some specific reactions) | Commonly (ATP is a universal energy currency) | ATP is a ribonucleotide used in most energy-requiring cellular processes. |
| Precursor to Polymerization | Synthesized in de novo or salvage pathways and incorporated into DNA via DNA polymerases | Incorporated into RNA via RNA polymerases | Both are tightly regulated in the cell to ensure proper nucleotide pool balance. |
| Chemical Reactivity | Less reactive due to absence of 2′-OH | More chemically reactive due to presence of 2′-OH | RNA can participate in catalytic activities (e.g., ribozymes); DNA cannot. |
| Base Pairing Rules | A pairs with T; G pairs with C | A pairs with U; G pairs with C | Complementarity is maintained but with different bases. |
| Detection Methods | Detected via DNA-specific dyes or probes (e.g., PicoGreen, SYBR Safe) | Detected with RNA-specific dyes or labeled probes (e.g., SYBR Green II, acridine orange) | Specific tools exist for nucleic acid discrimination in molecular biology. |
| Biotechnological Applications | Used in PCR, DNA sequencing, DNA cloning | Used in in vitro transcription, RNA sequencing, RNAi, and ribozyme studies | Both are vital for genetic engineering and synthetic biology. |
| Cellular Concentration | Lower compared to ribonucleotides | Generally higher, especially ATP | ATP acts both as a nucleotide and a cellular energy molecule. |
| Evolutionary Perspective | DNA evolved as a more stable storage form of genetic material | RNA is considered the original genetic material in early evolution | RNA world hypothesis suggests early life was RNA-based. |
