Antiparallel orientation
Definition
The two strands of the DNA double helix run in opposite directions: one strand reads 5' to 3', its complement reads 3' to 5'. DNA polymerase can only synthesise in the 5' to 3' direction, so this orientation determines how primers must be designed in PCR and how the leading and lagging strands differ during replication.
Related terms
- Denaturation
- The separation of double-stranded DNA into two single strands by disrupting the hydrogen bonds between base pairs. In PCR, denaturation is achieved...
- Base complementarity
- The specific pairing rules that govern double-stranded DNA: adenine pairs with thymine (2 hydrogen bonds) and guanine pairs with cytosine (3 hydrogen...
- Base pair (bp)
- A complementary pairing of nitrogenous bases on opposite strands of double-stranded DNA: adenine with thymine (two hydrogen bonds) or guanine with cytosine...
- Complementarity
- The property by which each base pairs with only one specific partner (A with T, G with C). Complementarity allows a single...
- Deoxyribonucleotide
- The monomer unit of DNA, consisting of a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases (adenine, thymine, guanine,...
- GC content
- The proportion of base pairs in a DNA molecule that are guanine-cytosine. Because G-C pairs form three hydrogen bonds (versus two for...
- Nucleotide
- The monomer unit of nucleic acids. Each nucleotide consists of a five-carbon sugar (deoxyribose in DNA, ribose in RNA), a phosphate group,...
- Phosphodiester backbone
- The repeating sugar-phosphate chain that forms the structural scaffold of each DNA strand. The backbone is highly charged and hydrophilic, faces outward...
- Phosphodiester bond
- The covalent linkage between consecutive nucleotides in a strand, formed between the phosphate group and the 3'-OH of the preceding sugar and...
Explained in these topics
- The DNA Double Helix and Base PairingThe arrangement of the two DNA strands so that they run in opposite chemical directions. If one strand is read 5' to 3' from top to bottom, the complementary s...
- Nucleic Acids: Structure and FunctionThe two strands of the DNA double helix run in opposite directions: one strand reads 5' to 3', its complement reads 3' to 5'. DNA polymerase can only synthesis...