The term "double helix" refers to the twisted ladder structure of DNA molecules, which is crucial for the transfer of genetic information. The spelling of "double helix" is represented in IPA phonetic transcription as /ˈdʌbəl ˈhɛlɪks/. The "d" sound at the beginning is followed by a short "u" and a soft "b". The second word is pronounced with a short "e" and a hard "l" sound that is emphasized on the first syllable. The final "s" sound is pronounced like a "z".
The term "double helix" refers to a fundamental structural shape found in molecular biology, particularly in the context of DNA (deoxyribonucleic acid). It represents the specific three-dimensional arrangement that two strands of DNA assume when they coil around each other, resembling a twisted ladder or spiral staircase. The structure can be characterized as a helix due to its distinctive spiral shape, while the term "double" indicates that it consists of two intertwined parallel strands.
The double helix of DNA is formed by a sequence of nucleotides, which are the building blocks of DNA. These nucleotides connect through hydrogen bonds, with adenine (A) bonding with thymine (T) and cytosine (C) bonding with guanine (G). This specific base pairing creates the stable structure of the double helix. The sugar-phosphate backbone of the DNA chains forms the outer sides of the helix, while the bases project inward and pair with their complementary bases from the opposite strand.
The discovery of the double helix structure of DNA is attributed to the scientists James Watson and Francis Crick in 1953, who performed the groundbreaking work leading to the understanding of DNA's role in hereditary information and its replication. The double helix structure has since become an iconic representation of DNA and has greatly contributed to our understanding of genetics, DNA sequencing, gene expression, and heredity.
The word "double helix" was coined by James Watson and Francis Crick in 1953 to describe the structure of DNA. The etymology of this term can be broken down as follows:
1. Double: The word "double" in English originates from the Latin word "duplus", meaning "twofold" or "double". It is derived from the combination of the prefix "duo", meaning "two", and the suffix "-plus", indicating "more" or "increased".
2. Helix: The word "helix" is derived from the Greek word "helix" or "helikos", which means "spiral" or "twisted". It refers to a three-dimensional curve that resembles a coiled spring or a twisted staircase.
Hence, combining these two terms, "double helix" signifies a structure that has two intertwined or twisted strands, representing the spiral structure of DNA.