Adenine and cytosine both are heterocyclic nitrogenous compounds, known as nucleobases. These are basic units of nucleic acids. Here we are going to compare and discuss all possible aspects regarding Adenine vs Cytosine.
Though Adenine (A) is a purine base and cytosine (C) is a pyrimidine base, they have several similarities and differences between them. Let’s have a closer look at the analytical study of Adenine vs Cytosine.
| Characteristics | Adenine (A) | Cytosine (C) |
| Definition | Adenine (A) is one of two Purine derivative nitrogenous bases, having an amine group in its C-6 position, used as structural and functional subunit in nucleic acids. | Cytosine is one of the two pyrimidine derivative nitrogenous bases, havingan amine group at position 4 and a keto group at position 2 of its ring,used as structural and functional material of nucleic acids. |
| Type of nitrogenous base | Purine | Pyrimidine |
| Functional groups | An amine group on C-6 position of ring | an amine group at position 4 and a keto group at position 2 of its ring |
| Formula | C5H5N5 | C4H5N3O |
| Base pairing | Thymine or uracil | Guanine |
| Molar mass | 135.13 g/mol | 111.10 g/mol |
| Melting point | 360 to 365 °C (680 to 689 °F; 633 to 638 K) | 320 to 325 °C (608 to 617 °F; 593 to 598 K) |
| Density | 1.6 g/cm3 | 1.55 g/cm3 |
| Acidity (pKa) | 4.15 (secondary), 9.80 (primary) | 4.45 (secondary), 12.2 (primary) |
| Nucleoside formed | Adenosine | Cytidine |
| Nucleotides formed | adenosine triphosphate (ATP), Adenosine monophosphate (AMP), Adenosine diphosphate (ADP), nicotinamide adenine dinucleotide (NAD), flavin adenine dinucleotide (FAD) | Cytidine monophosphate (CMP) , Cytidine diphosphate (CDP) and Cytidine triphosphate (CTP). |
| Hydrogen bond formation | Double bonds | Triple bonds |
| Functions | The main function of adenine is to serve as a structural and functional subunit of nucleic acids. As AMP, ATP and ADP, it serves as an energy source in cellular reactions. | As nucleotides it acts as a structural and functional subunit of nucleic acids. It helps in signal transduction pathways, serve as cofactor and also possess some enzymatic activities in cells. |
| Synonyms | 6-Aminopurine | 4-Amino-1H-pyrimidine-2-one |
Adenine vs Cytosine
From analytical comparison of Adenine vs Cytosine these similarities and differences are found between these two nitrogenous chemical compounds of nucleic acids.
Nucleobases in nucleic acids from Wikimedia Commons
Adenine vs Cytosine in summary
Based on the above mentioned comparative analysis, here we describe a summary of Adenine vs Cytosine.
Definition
- Adenine (A): Adenine is one of two Purine derivatives (another one is Guanine), used as structural and functional subunit in nucleic acids (DNA and RNA). In association with a pentose sugar and phosphate groups it serves as the energy currency of a cell.
- Cytosine (C): Cytosine is one of the two pyrimidine derivatives ( another one is Thymine), used as a structural and functional subunit of nucleic acids.
Type of nitrogenous base
- Adenine (A): It is a purine base.
- Cytosine (C): It is a pyrimidine base.
Functional groups
- Adenine (A): Adenine has an amine group (-NH2) at the 6-carbon position of its heterocyclic ring.
- Cytosine (C): Cytosine has an amine group at 4-carbon position and a keto group at 2- carbon position of its heterocyclic ring.
Formula
- Adenine (A): The chemical formula of Adenine (A) is C5H5N5.
- Cytosine (C): The chemical formula of Cytosine (C) is C4H5N3O.
Base pairing
- Adenine (A): It pairs with pyrimidine base Thymine (T) or Uracil (U) with hydrogenous double bonds.
- Cytosine (C): Cytosine makes complementary base pair with purine base Guanine (G) and makes hydrogenous triple bonds.
Molar mass
- Adenine (A): The molar mass or molecular weight of Adenine is 135.13 g/mol.
- Cytosine (C): The molar mass or molecular weight of Cytosine is 111.10 g/mol.
Melting point
- Adenine (A): The melting point of adenine is 360 to 365 °C (680 to 689 °F; 633 to 638 K).
- Cytosine (C): The melting point of Cytosine is 320 to 325 °C (608 to 617 °F; 593 to 598 K).
Density
- Adenine (A): The adenine has molecular density of 1.6 g/cm3
- Cytosine (C): The Cytosine has molecular density of 1.55 g/cm3
Acidity (pKa)
- Adenine (A): The Adenine is much weaker in case of acidity than the others. It has a pKa value of 4.15 (secondary), 9.80 (primary).
- Cytosine (C): The Cytosine has pKa value of 4.45 (secondary), 12.2 (primary).
Nucleoside formed
- Adenine (A): Along with a five carbon sugar moiety, the adenine forms a nucleoside, called Adenosine.
- Cytosine (C): Along with a five carbon sugar unit ( deoxyribose or ribose sugar) the Cytosine forms a nucleoside, named Cytidine.
Nucleotides formed
- Adenine (A): Adenine form several nucleotide units, such as Adenosine triphosphate (ATP), Adenosine monophosphate (AMP), Adenosine diphosphate (ADP), nicotinamide adenine dinucleotide (NAD), flavin adenine dinucleotide (FAD), etc.
- Cytosine (C): Cytosine forms many nucleotide units with association of a pentose sugar and phosphate groups. Such as Cytidine monophosphate (CMP) , Cytidine diphosphate (CDP), Cytidine triphosphate (CTP), etc.
Hydrogen bond formation
- Adenine (A): Adenine forms hydrogenous double bonds with pyrimidine base Thymine (T) in DNA structure or with Uracil (U) in RNA Structure.
- Cytosine (C): Cytosine forms hydrogenous triple bonds with purine base Guanine (G) in both of the nucleic acids.
Functions
- Adenine (A): Adenine is used as the structural and functional subunit in nucleic acids. As a part of codon it influences protein synthesis, carries genetic heredity as a part of nucleic acids. As nucleotides it acts as an energy source of cells, transferring energy during cellular reactions.
- Cytosine (C): Just like other nucleobases, Cytosine is also used as the structural and functional subunit in nucleic acids. As a part of codon it influences protein synthesis, carries genetic heredity as a part of nucleic acids. It also serves as an enzymatic cofactor in the cell.
Synonyms
- Adenine (A): Adenine also known as 6-Aminopurine.
- Cytosine (C): Cytosine also known as 4-Amino-1H-pyrimidine-2-one.
Adenine and cytosine from Wikimedia Commons
To know more read on Nucleotides In DNA Structure: Comparative Analysis Across It
Are Cytosine (C) and Adenine (A) the same?
Cytosine (C) and Adenine (A) both are nitrogenous nucleobases that serve as structural and functional subunits of nucleic acids.
Though Cytosine and Adenine possess several similarities between them, they are not the same. The cytosine is a pyrimidine base having two substituents and a heterocyclic ring. Adenine has a pyrimidine and imidazole ring in its structure. Thus the Citosine (C) and Adenine (A) are not same.
Adenine structure from Wikimedia Commons
To know more read on Adenine Vs Thymine: Comparative Analysis
Can Adenine (A) base pairs with Cytosine (C)?
Adenine and cytosine both are nucleobases, make base pairs to stabilize the nucleic acid structure.
Adenine do not makes base pair with Cytosine. Adenine pairs with Thymine or Uracil. It makes hydrogenous double bonds with them.
Cytosine makes complementary base pair with Guanine (hydrogenous triple bonds).
Read on more about Nucleotide Structure | A detailed insight and its significance
Is Adenine (A) a purine?
There are two different purine bases present in nucleic acids, Adenine (A) and Guanine (G).
As a purine base Adenine (A) contains a pyrimidine ring and a imidazole ring in its structure. It is consist two carbon-nitrogen ring and four nitrogen atoms in its structure . Thus, adenine is a typical purine base.
Is Cytosine (C) a pyrimidine?
There are two different pyrimidine bases in nucleic acids, Guanine (G) and Cytosine (C).
As a pyrimidine, Cytosine contains a carbon-nitrogen ring and two nitrogen atoms in its structure. Thus Cytosine is typically a pyrimidine base.
As a whole we can say that adenine and Cytosine are one of the most important nitrogenous compounds in cell. Here we discuss every aspect of Adenine vs Cytosine, stating the analytical information in brief. Hope this comparative analysis of Adenine vs Cytosine will be useful to you.
Also Read:
- Lysis in cell wall
- Vibrio bacteria examples
- Saprophytic fungi examples
- Does lysosome have membrane
- Staphylococcus bacteria examples
- Woody plants examples
- Cocci bacteria examples
- Heterotroph vs autotroph
- Can dna leave the nucleus
- Cytoskeleton structure
Hello, I am Piyali Das, pursuing my Post Graduation in Zoology from Calcutta University. I am very passionate on Academic Article writing. My aim is to explain complex things in simple way through my writings for the readers.