Nucleic acids and DOGMA

DNA

Deoxyribonucleic acid, the hereditary material in humans and almost all other organisms.

RNA

Ribonucleic acid, a nucleic acid involved in protein synthesis and gene expression.

Nucleotides

The building blocks of nucleic acids, consisting of a phosphate group, a pentose sugar, and a nitrogenous base.

Phosphate group

A component of nucleotides that joins with sugars to form the backbone of DNA and RNA.

Pentose sugar

A five-carbon sugar molecule found in nucleotides; either ribose in RNA or deoxyribose in DNA.

Nitrogenous base

A component of nucleotides; in DNA: Adenine (A), Thymine (T), Guanine (G), Cytosine (C); in RNA: Adenine (A), Uracil (U), Guanine (G), Cytosine (C).

Antiparallel

Describes the orientation of the two strands of DNA running in opposite directions.

Phosphodiester bonds

Covalent bonds that link nucleotides together in a polynucleotide chain.

Complementary base pairing

The specific pairing of nitrogenous bases in DNA; Adenine pairs with Thymine (A-T) and Cytosine pairs with Guanine (C-G).

ATP

Adenosine triphosphate, a molecule similar to a nucleotide that provides energy for many cellular processes.

Translation

The process by which cells convert the genetic information in mRNA into a sequence of amino acids.

Ribosome

A cellular structure made of rRNA and protein where protein synthesis occurs.

tRNA

Transfer RNA, a type of RNA that carries amino acids to the ribosome to match them with mRNA codons.

Transcription

The synthesis of RNA from a DNA template.

Template strand

The DNA strand that is transcribed to produce mRNA.

Coding strand

The non-template DNA strand that has the same sequence as the mRNA (except for T's instead of U's).

Codons

Three-letter sequences of nucleotides in mRNA that encode specific amino acids.

RNA polymerase

The enzyme that synthesizes RNA during transcription.

Initiation (transcription)

The process where RNA polymerase binds to a promoter to begin transcription.

Termination (transcription)

The end step in transcription when RNA polymerase reaches a terminator and releases the mRNA.

Post-transcriptional modifications

Processes such as capping, polyadenylation, and splicing that occur to mRNA after transcription.

Introns

Non-coding sequences removed during RNA splicing.

Exons

Coding sequences that remain in the mRNA after splicing.

Semi-conservative replication

A method of DNA replication where each new DNA molecule consists of one old strand and one new strand.

Helicase

An enzyme that unwinds the DNA double helix during replication.

DNA ligase

An enzyme that joins Okazaki fragments on the lagging strand during DNA replication.

Okazaki fragments

Short segments of DNA synthesized on the lagging strand during DNA replication.