Week 11, 15, 16 vocab

Alternative splicing

A process by which a single gene can lead to multiple mRNA variants through the inclusion or exclusion of different exons.

Aminoacyl-tRNA synthetases

Enzymes that attach the correct amino acid to its corresponding tRNA, enabling translation of mRNA into proteins.

Anticodon loop

A region of tRNA that contains a three-nucleotide sequence complementary to a codon on mRNA, allowing for accurate translation.

A (aminoacyl) site

The location on the ribosome where the aminoacyl-tRNA binds during protein synthesis.

Base substitution

A type of mutation where one nucleotide in the DNA sequence is replaced by another, potentially altering the resulting protein.

5′ cap

A modified guanine nucleotide added to the 5′ end of eukaryotic mRNA that protects the mRNA from degradation and aids in ribosome binding.

Central dogma

The framework describing the flow of genetic information from DNA to RNA to protein.

Charged tRNA

A tRNA molecule that is linked to its corresponding amino acid, ready for incorporation into a growing polypeptide chain.

Chromatin-remodeling complexes

Protein complexes that modify chromatin structure, allowing for access to DNA for transcription and replication.

Codon

A three-nucleotide sequence in mRNA that specifies a particular amino acid or a stop signal during protein synthesis.

Copy number variation (CNV)

Structural variations in the genome where sections of DNA are repeated, leading to differences in gene dosage.

Core polymerase

The essential enzyme component of RNA polymerase responsible for synthesizing RNA from a DNA template.

DNA methylation

The addition of methyl groups to DNA, typically affecting gene expression by repressing transcription.

Elongation factor

Proteins that facilitate the elongation phase of translation or transcription by assisting the addition of nucleotides or amino acids.

E (exit) site

The location on the ribosome where the empty tRNA, having released its amino acid, exits the ribosome.

Enhancers

Regulatory DNA sequences that can significantly increase the transcription of specific genes from a distance.

Exons

Coding regions of a gene that are retained in the final mRNA product after splicing.

Frameshift mutations

Mutations caused by insertions or deletions of nucleotides that change the reading frame of the gene, often leading to nonfunctional proteins.

Genetic code

The set of rules by which information encoded in mRNA is translated into proteins.

Helix-turn-helix motif

A common structural motif in proteins that allows for binding to DNA, often found in transcription factors.

Holoenzyme

The active form of an enzyme that includes the core enzyme plus any necessary cofactors or regulatory proteins.

Homeodomain

A conserved protein domain that binds to DNA, often involved in regulating development and gene expression.

Initiation complex

The assembly of mRNA, ribosomal subunits, and the initiator tRNA that begins the process of translation.

Introns

Non-coding regions of a gene that are removed during RNA processing before translation.

Induction

The process by which a molecule (inducer) increases gene expression, often by inhibiting a repressor.

Lac operon

A set of genes in bacteria that are regulated together and are involved in the metabolism of lactose.

Lariat

A loop structure formed during the splicing of introns from pre-mRNA.

Leucine zipper motif

A structural motif in proteins that facilitates dimerization and DNA binding, characterized by repeating leucine residues.

Mature mRNA

The final processed form of mRNA that contains only exons and is ready for translation.

Messenger RNA (mRNA)

A type of RNA that carries genetic information from DNA to the ribosome, where proteins are synthesized.

Missense mutation

A type of mutation that results in the substitution of one amino acid for another in a protein.

Negative control

A regulatory mechanism in which a repressor protein inhibits gene expression.

Nonsense mutations

Mutations that create a premature stop codon in a protein-coding sequence, leading to truncated proteins.

Operon

A cluster of genes under the control of a single promoter, often involved in related metabolic pathways in prokaryotes.

Peptidyl transferase

An enzymatic function of the ribosome that forms peptide bonds between amino acids during translation.

P (peptidyl) site

The site on the ribosome where the tRNA carrying the growing polypeptide chain is located.

Point mutation

A mutation that affects a single nucleotide in the DNA sequence, potentially altering the protein produced.

Positive control

A regulatory mechanism in which an activator protein enhances gene expression.

Promoter

A DNA sequence located upstream of a gene where RNA polymerase binds to initiate transcription.

Proteome

The entire set of proteins expressed by a genome at a given time.

Regulatory proteins

Proteins that control the rate of transcription of genetic information by binding to nearby DNA.

Repression

The process by which gene expression is inhibited, often by repressor proteins binding to the promoter or other regulatory regions.

Ribosomal RNA (rRNA)

The RNA component of ribosomes, crucial for protein synthesis.

Ribosome binding sequence (RBS)

A sequence on mRNA that is recognized by ribosomes, facilitating the initiation of translation in prokaryotes.

RNA polymerase

The enzyme responsible for synthesizing RNA from a DNA template during transcription.

RNA polymerase I, II, and III

Different forms of RNA polymerase in eukaryotic cells, each responsible for synthesizing specific types of RNA.

RNA Pol I promoters

Promoters that regulate the transcription of rRNA genes by RNA polymerase I.

RNA Pol II promoters

Promoters that regulate the transcription of mRNA and some snRNA genes by RNA polymerase II.

RNA Pol III promoters

Promoters that regulate the transcription of tRNA and rRNA genes by RNA polymerase III.

3′ poly-A tail (Polyadenylation)

A stretch of adenine nucleotides added to the 3′ end of eukaryotic mRNA, enhancing stability and translation.

Signal recognition particle RNA (SRP RNA)

RNA that is part of the signal recognition particle, which targets proteins for secretion.

Silent mutation

A mutation that does not change the amino acid sequence of a protein.

Small ribonucleoprotein particles (snRNPs)

Complexes of RNA and protein that play a crucial role in splicing pre-mRNA.

Small nuclear RNA (snRNA)

A class of RNA molecules that are involved in the splicing of pre-mRNA.

Small RNAs (miRNA and siRNA)

Short RNA molecules that regulate gene expression by targeting mRNA for degradation or inhibition of translation.

Spliceosome

A complex of snRNPs and proteins that catalyzes the splicing of introns from pre-mRNA.

Start site

The nucleotide in the DNA where transcription begins.

Terminator

A sequence in DNA that signals the end of transcription.

Transcription

The process by which RNA is synthesized from a DNA template.

Transcription unit

The segment of DNA that is transcribed into RNA.

Transcriptome

The complete set of RNA transcripts produced by the genome at a given time.

Transfer RNA (tRNA)

The type of RNA that carries amino acids to the ribosome during protein synthesis.

Translation

The process of synthesizing a protein from mRNA.

Triplet repeat mutation

A mutation characterized by the expansion of a repeat sequence of three nucleotides in a gene.

Wobble pairing

A concept explaining how certain tRNA anticodon nucleotides can pair with more than one codon due to flexible base pairing.

Zinc finger motif

A protein structure that binds to DNA, typically involved in transcription regulation.

TFIID = transcription factor RNA polymerase II

A multi-subunit protein complex that plays a crucial role in the initiation of transcription by RNA polymerase II.

Posttranscriptional regulation

The control of gene expression at the RNA level after transcription has occurred.