DNA - Wikipedia
网页The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides. [2] [3] Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group.
DNA | Definition, Discovery, Function, Bases, Facts, & Structure ...
网页5 天之前 · Each strand of a DNA molecule is composed of a long chain of monomer nucleotides. The nucleotides of DNA consist of a deoxyribose sugar molecule to which is attached a phosphate group and one of four nitrogenous bases: two purines (adenine and guanine) and two pyrimidines (cytosine and thymine).
Deoxyribonucleic Acid (DNA) Fact Sheet - National Human …
网页2020年8月24日 · To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating. The four types of nitrogen bases found in nucleotides are: adenine (A), thymine (T), guanine (G) and cytosine (C).
DNA Structure - Biology Dictionary
网页2021年1月21日 · The nucleotides that make up DNA are joined together like a long string of beads, called a DNA strand. Each DNA molecule contains two DNA strands, which are twisted around one another to make a spiral-like shape called the double helix.
9.1: The Structure of DNA - Biology LibreTexts
网页2022年3月17日 · A DNA molecule is composed of two strands. Each strand is composed of nucleotides bonded together covalently between the phosphate group of one and the deoxyribose sugar of the next. From this backbone extend the bases.
DNA Structure and Functions - Science Facts
网页2023年9月13日 · The two DNA strands (polymers) wound around each other in a right-handed double helix that looks like a twisted ladder or a spiral-shaped staircase. Each helix turn or complete double helix rotation measures approximately 34 Angstroms (Å) in length.
Deoxyribonucleic Acid (DNA) - National Human Genome …
网页1 天前 · Deoxyribonucleic acid (abbreviated DNA) is the molecule that carries genetic information for the development and functioning of an organism. DNA is made of two linked strands that wind around each other to resemble a …
7.1: DNA Structure - Biology LibreTexts
网页2022年12月30日 · DNA normally exists as a two antiparallel complementary strands held together by hydrogen bonds between adenines (A) and thymines (T), and between guanines (G) and cytosines (C). DNA is normally found as a double-stranded molecule in the cell whereas RNA is mostly single-stranded.
DNA - Definition, Function, Structure and Discovery - Biology …
网页2019年4月8日 · DNA is usually a double-stranded polymer of nucleotides, although single-stranded DNA is also known. Nucleotides in DNA are molecules made of deoxyribose sugar, a phosphate and a nitrogenous base. The nitrogenous bases in DNA are of four types – adenine, guanine, thymine and cytosine.
9.1 The Structure of DNA - Concepts of Biology - OpenStax
网页Watson and Crick proposed that the DNA is made up of two strands that are twisted around each other to form a right-handed helix, called a double helix. Base-pairing takes place between a purine and pyrimidine: namely, A pairs with T, and G pairs with C.