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This nucleotide contains the five-carbon sugar deoxyribose (at center), a nucleobase called adenine (upper right), and one phosphate group (left). The deoxyribose sugar joined only to the nitrogenous base forms a Deoxyribonucleoside called deoxyadenosine, whereas the whole structure along with the phosphate group is a nucleotide, a constituent of DNA with the name deoxyadenosine monophosphate.
All living cells contain both DNA and RNA (except some cells such as mature red blood cells), while viruses contain either DNA or RNA, but usually not both. [15] The basic component of biological nucleic acids is the nucleotide, each of which contains a pentose sugar (ribose or deoxyribose), a phosphate group, and a nucleobase. [16]
The 5'-phosphate group of one nucleotide is linked to the 3'-hydroxyl group of the next nucleotide, creating a backbone of alternating phosphate and pentose residues. There is no phosphodiester bond at each end of the polynucleotide. [5] Phosphodiester bonds are formed between ribonucleotides by the enzyme RNA polymerase.
A nucleic acid sequence is the order of nucleotides within a DNA (GACT) or RNA (GACU) molecule that is determined by a series of letters. Sequences are presented from the 5' to 3' end and determine the covalent structure of the entire molecule.
Detailed diagram of lipid bilayer of cell membrane. The cell membrane, or plasma membrane, is a selectively permeable [citation needed] biological membrane that surrounds the cytoplasm of a cell. In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall.
Illustration of a eukaryotic cell membrane Comparison of a eukaryotic vs. a prokaryotic cell membrane. The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space).
DNA replication occurs so, during cell division, each daughter cell contains an accurate copy of the genetic material of the cell. 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.
Fluid mosaic model of a cell membrane. The fluid mosaic model explains various characteristics regarding the structure of functional cell membranes.According to this biological model, there is a lipid bilayer (two molecules thick layer consisting primarily of amphipathic phospholipids) in which protein molecules are embedded.