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The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Cytosine (/ ˈ s aɪ t ə ˌ s iː n,-ˌ z iː n,-ˌ s ɪ n / [2] [3]) (symbol C or Cyt) is one of the four nucleotide bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group ...
Both RNA and DNA contain two major purine bases, adenine (A) and guanine (G), and two major pyrimidines. In both DNA and RNA, one of the pyrimidines is cytosine (C). However, DNA and RNA differ in the second major pyrimidine. DNA contains thymine (T) while RNA contains uracil (U). There are some rare cases where thymine does occur in RNA and ...
The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is deoxyribose, a variant of ribose, the polymer is DNA. Nucleic acids are chemical compounds that are found in nature. They carry information in cells and make up genetic material.
Double-stranded RNA (dsRNA) is RNA with two complementary strands, similar to the DNA found in all cells, but with the replacement of thymine by uracil and the adding of one oxygen atom. dsRNA forms the genetic material of some viruses (double-stranded RNA viruses).
In vivo DNA synthesis (DNA replication) is dependent on a complex set of enzymes which have evolved to act during the S phase of the cell cycle, in a concerted fashion. In both eukaryotes and prokaryotes , DNA replication occurs when specific topoisomerases , helicases and gyrases (replication initiator proteins) uncoil the double-stranded DNA ...
In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from altering the number of copies of RNA that are transcribed, to the temporal control of when the gene is ...
The cell cycle is a series of complex, ordered, sequential events that control how a single cell divides into two cells, and involves several different phases. The phases include the G1 and G2 phases, DNA replication or S phase, and the actual process of cell division, mitosis or M phase. [1]