Define each of the following terms:

nucleic acid strand polarity

Key Concepts

Nucleic Acid Structure

Nucleic acids, such as DNA and RNA, are polymers made up of nucleotide monomers. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base. The sequence of these nucleotides encodes genetic information, and the structure of nucleic acids is crucial for their function in biological systems.

Strand Polarity

Nucleic acid strands have directionality, often referred to as polarity, which is defined by the orientation of the sugar-phosphate backbone. Each strand has a 5' end, where a phosphate group is attached, and a 3' end, where a hydroxyl group is present. This polarity is essential for processes like DNA replication and transcription, as enzymes read and synthesize nucleic acids in a specific direction.

Antiparallel Orientation

In double-stranded DNA, the two strands run in opposite directions, a configuration known as antiparallel orientation. This means that one strand runs from 5' to 3', while the complementary strand runs from 3' to 5'. This arrangement is critical for the base pairing between the strands and for the proper functioning of enzymes involved in DNA replication and repair.