genes and rna

RNA

Ribonucleic acid, a molecule made of nucleotides that carry genetic information.

Nucleotide

The basic building block of RNA, consisting of a ribose sugar, phosphate group, and nitrogenous base.

Uracil (U)

A nitrogenous base in RNA that pairs with adenine and replaces thymine found in DNA.

mRNA (Messenger RNA)

RNA that carries genetic information from DNA to the ribosome for protein synthesis.

rRNA (Ribosomal RNA)

RNA that is a structural and functional component of ribosomes, involved in protein synthesis.

tRNA (Transfer RNA)

RNA that transfers specific amino acids to the ribosome during protein synthesis.

Anticodon

A three-base sequence on tRNA that is complementary to the codon on mRNA.

Transcription

The process where RNA polymerase synthesizes mRNA from a DNA template.

Exons

Coding regions of a gene that are expressed in the final mRNA.

Introns

Noncoding regions of a gene that are removed during mRNA processing.

Polypeptide

A chain of amino acids that makes up a protein.

Activation (in translation)

The process of bonding amino acids to tRNA, producing charged tRNA.

Initiation (in translation)

The first step of translation where the ribosome assembles on the mRNA, starting with the start codon.

Elongation (in translation)

The step in translation where amino acids are sequentially added to a growing polypeptide chain.

Termination (in translation)

The step in translation where the ribosome reaches a stop codon and releases the polypeptide.

One Gene–One Enzyme Hypothesis

A hypothesis stating that each gene encodes a single enzyme (or protein), proposed by Beadle and Tatum.