Gene Expression: From Genes to Proteins

Vocabulary flashcards covering key terms and definitions related to gene expression, transcription, translation, and the molecular machinery involved.

Gene Expression

The process by which DNA directs protein synthesis.

Transcription

The first step of gene expression, where DNA is transcribed to RNA.

Translation

The process where messenger RNA is translated into a polypeptide.

Ribosome

Molecular machinery that facilitates the translation of mRNA into proteins.

mRNA

Messenger RNA, the RNA molecule that carries genetic information from DNA.

tRNA

Transfer RNA, which translates mRNA codons into amino acids.

rRNA

Ribosomal RNA, a component of ribosomes that facilitates translation.

Codon

A three-nucleotide sequence in mRNA that specifies an amino acid.

Anticodon

A three-nucleotide sequence in tRNA that is complementary to an mRNA codon.

Promoter

A DNA sequence that signals the beginning of transcription.

Terminator

A sequence in DNA that signals the end of transcription.

RNA Polymerase

The enzyme responsible for synthesizing RNA from the DNA template.

Intron

Non-coding regions of pre-mRNA that are removed during RNA splicing.

Exon

Coding regions of pre-mRNA that remain in mature mRNA.

5' Cap

A modified guanosine added to the 5' end of mRNA to protect it from degradation.

Poly-A Tail

A string of adenine nucleotides added to the 3' end of mRNA.

Alternative RNA Splicing

The process by which various combinations of exons are joined to produce different mRNAs.

Central Dogma

The flow of genetic information from DNA to RNA to protein.

Amino Acid

The building blocks of proteins, specified by mRNA codons.

Polypeptide

A chain of amino acids that folds into a functional protein.

Stop Codon

A codon that signals the end of translation (UAA, UAG, UGA).

Start Codon

The codon (AUG) that signals the start of translation.

Reading Frame

The way nucleotides are divided into codons to be read by the ribosome.

Peptide Bond

A covalent bond formed between two amino acids in a polypeptide.

Sigma Factor

A protein that helps RNA polymerase recognize the promoter region in prokaryotes.

Post-Transcriptional Modification

Changes made to pre-mRNA before it becomes mature mRNA.

snRNP

Small nuclear ribonucleoproteins that are involved in splicing pre-mRNA.

Spliceosome

A complex of snRNPs that removes introns from pre-mRNA.

Degenerate Code

The genetic code is degenerate; multiple codons can code for the same amino acid.

Hydrolysis of GTP

The process providing energy for the assembly and function of ribosomes during translation.

Polyribosome

A cluster of ribosomes translating the same mRNA strand simultaneously.

Cytoplasm

The fluid inside a cell where protein synthesis occurs.

Nucleus

The cellular organelle where transcription takes place in eukaryotes.

Eukaryotic RNA Processing

The modification of pre-mRNA, including capping, tailing, and splicing.

Transcription Factors

Proteins that influence the ability of RNA polymerase to transcribe genes.

Nucleotide

The basic building block of nucleic acids (DNA and RNA).

Template Strand

The strand of DNA used by RNA polymerase to synthesize mRNA.

Non-coding RNA

RNA molecules that do not encode proteins.

Aminoacyl-tRNA Synthetase

An enzyme that attaches the correct amino acid to its corresponding tRNA.

Wobble Base Pairing

Flexibility in base pairing at the third position of the codon, allowing for multiple matches.

Ribozyme

An RNA molecule that acts as an enzyme, catalyzing biochemical reactions.

Gene

A segment of DNA that contains the necessary information for producing a functional product.

RNA Modification

Chemical changes to RNA after transcription, including capping and splicing.

mRNA Codons

The sequences of three nucleotides that correspond to a specific amino acid.

Polypeptide Chain

A linear chain of amino acids forming a protein.

E site

Exit site in a ribosome where uncharged tRNA leaves.

P site

Peptidyl site in a ribosome where the polypeptide is attached to tRNA.

A site

Aminoacyl site in a ribosome where the charged tRNA and amino acid enter.

Termination Factors

Proteins that recognize stop codons and facilitate the end of translation.