Gene Expression and Regulation

The process of modifying a newly transcribed RNA molecule (pre-mRNA) into a mature mRNA molecule that can be translated into protein.

Eukaryotic cells have a separate compartment for transcription (nucleus) and translation (cytoplasm), so mRNA processing must occur before translation.

A modified guanine nucleotide added to the 5' end of the pre-mRNA molecule. It protects the mRNA from degradation and helps initiate translation.

A string of adenine nucleotides added to the 3' end of the pre-mRNA molecule. It helps with mRNA stability, transport, and translation.

The removal of non-coding sequences (introns) from the pre-mRNA molecule, leaving only the coding sequences (exons) that are translated into protein.

A complex of proteins that includes TBP (TATA-binding protein) and TAFs (transcription-associated factors). It binds to the promoter region of a gene, helping RNA polymerase II to initiate transcription.

A protein that binds to the TATA box within the promoter region of a gene. It helps to position RNA polymerase II correctly for transcription initiation.

A complex of proteins that assembles at the promoter region of a gene, including RNA polymerase II, general transcription factors (B,E,F,H), and TFIID. It is crucial for initiating transcription by RNA polymerase II.

A protein complex that acts as a bridge between the pre-initiation complex (PIC) and activator proteins. It helps to regulate the efficiency of transcription initiation.

The process where a phosphate group is added to the C-terminal domain (CTD) of RNA polymerase II. This modification is essential for releasing Mediator and other general transcription factors, allowing RNA polymerase II to begin elongation.

A sequence of adenine nucleotides added to the 3' end of mRNA molecules, typically around 200 adenines long.

An enzyme responsible for adding the poly-A tail to mRNA molecules.

The process of removing introns from pre-mRNA, leaving only exons.

A complex of small nuclear RNAs (snRNAs) and proteins that catalyzes the removal of introns from pre-mRNA.

RNA molecules that have enzymatic activity, specifically involved in the splicing process.

A type of RNA that carries genetic information from the nucleus to the ribosome for protein synthesis.

Specialized RNA molecules that carry amino acids to the ribosomes for protein synthesis.

A complex molecular machine responsible for translating the mRNA code into a protein sequence

The process where genetic information in mRNA is decoded into a protein sequence, resulting in the formation of a protein.

The process of adding a 5' cap to pre-mRNA, which is required for proper translation and stability of the mRNA molecule.

The addition of a long chain of adenine nucleotides (poly-A tail) to the 3' end of a pre-mRNA molecule.

A sequence in the pre-mRNA molecule that signals for polyadenylation, usually consisting of AAUAAA and surrounding sequences.

An enzyme that cleaves or breaks pre-mRNA at a specific location, typically downstream of the polyadenylation signal.

A sequence in the pre-mRNA molecule that is often recognized by an endonuclease for cleavage, typically consisting of CA.

Non-coding sequences within a pre-mRNA molecule that are removed during splicing.

Coding sequences within a pre-mRNA molecule that are joined together after splicing.

A type of linkage in nucleic acids that links 5' phosphate group of one nucleotide to the 3' hydroxyl group of the next nucleotide.

A type of RNA that makes up the structural scaffold of ribosomes and plays a role in the catalytic activity of protein synthesis.

A type of RNA that carries specific amino acids to the ribosome during translation, based on the mRNA sequence.

The three binding sites on a ribosome where tRNA molecules interact during translation, named after their roles in the process: A (Aminoacyl) - Incoming tRNA, P (Peptidyl) - tRNA carrying the growing polypeptide chain, E (Exit) - Empty tRNA leaving the ribosome.