Gene expression

Genes are specific sequences of DNA that contain the information a cell needs for its functions. During transcription, sections of DNA act as templates for assembling RNA molecules: in particular, this type of RNA that stores DNA information is called messenger RNA, or mRNA. Transcription factors, a class of cell proteins, determine when the transcription process occurs and which DNA sequences are involved. During the first steps in transcription, transcription factors and its associated RNA polymerase bind to the DNA at a specific point that facilitates transcription, known as promoter region. RNA polymerase creates a new strand of mRNA by stringing together a chain of complementary nucleotides. During translation, the mRNA sequence is read by a structure within the cell, a ribosome, which uses it as a template for protein assembly.