Genetic Code and Translation

This set of flashcards covers key vocabulary and concepts related to the genetic code and the process of translation in molecular biology.

Genetic Code

The set of rules used by living cells to translate information encoded within genetic material into proteins.

Central Dogma of Molecular Biology

The model that describes the flow of genetic information in cells from DNA to mRNA to protein.

Redundancy of the Genetic Code

The property that multiple codons can encode the same amino acid.

Codon

A sequence of three nucleotides in mRNA that specifies an amino acid.

Start Codon

The codon that begins translation, typically AUG, which codes for methionine.

Stop Codons

Codons that signal the termination of protein synthesis: UAA, UAG, UGA.

Triplet Code

A genetic code that consists of triplets of nucleotides.

Non-overlapping Code

A genetic code in which each nucleotide is part of only one codon.

Wobble Hypothesis

The idea that the third base of a codon can vary, allowing a single tRNA to recognize multiple codons.

Aminoacyl-tRNA Synthetase

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

Peptide Bond

The chemical bond formed between amino acids during protein synthesis.

Translation

The process of synthesizing proteins from mRNA.

Elongation

The stage in translation where the polypeptide chain grows by adding amino acids.

Termination

The final stage of translation when the ribosome recognizes a stop codon.

mRNA

Messenger RNA that carries genetic information from DNA to the ribosome.

tRNA

Transfer RNA that delivers amino acids to the ribosome during translation.

Ribosome

The molecular machine that facilitates the synthesis of proteins by translating mRNA.

Polypeptide Chain

A chain of amino acids linked by peptide bonds, which folds into a functional protein.

Degenerate Code

The property of the genetic code that allows for several codons to encode the same amino acid.

Mutation

A change in the DNA sequence that can lead to changes in protein structure and function.

Frameshift Mutation

A mutation caused by insertion or deletion of nucleotides that alters the reading frame.

Initiation Complex

The assembly of ribosomal subunits and initiation factors at the start codon of mRNA.

Quality Control in Translation

Mechanisms to ensure accurate protein synthesis, such as mRNA surveillance.

Polyribosome

A complex of multiple ribosomes translating a single mRNA molecule simultaneously.

5' Untranslated Region (UTR)

The region of mRNA upstream of the start codon that is not translated into protein.

3' Untranslated Region (UTR)

The region of mRNA downstream of the stop codon that is not translated into protein.

Shine-Dalgarno Sequence

A ribosomal binding site in bacterial mRNA, important for initiation of translation.

Ribosomal RNA (rRNA)

RNA components of ribosomes that play crucial roles in the translation process.

Eukaryotic Translation Initiation

The complex steps that occur in the beginning of translation in eukaryotic cells.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, often a protein.

Covalent Linkage

The strong bond formed between amino acids and tRNA during tRNA charging.

mRNA Surveillance Mechanism

A cellular system that detects and degrades mRNAs with errors, such as premature stop codons.

Chaperone Proteins

Proteins that assist in the proper folding of other proteins.

Deacylated tRNA

tRNA that has released its attached amino acid and is ready for recharging.

GTP Hydrolysis

The conversion of GTP to GDP that provides energy for various cellular processes, including translation.

Catalysis by Ribosomal RNA

The role of rRNA in driving peptide bond formation and other enzymatic functions during translation.

Inosine (I)

A nucleotide that can pair with multiple bases in codon-anticodon interactions, contributing to wobble.

Eukaryotic Ribosome Structure

The structure of ribosomes in eukaryotes, made of large (60S) and small (40S) subunits.

Bacterial Ribosome Structure

The structure of ribosomes in bacteria, consisting of large (50S) and small (30S) subunits.

Protein Folding

The process by which a polypeptide folds into its functional three-dimensional structure.

Ribosome Binding Sites

The regions in the ribosome where tRNA molecules bind during translation: A, P, and E sites.

Nonsense Mutation

A mutation that creates a premature stop codon, truncating protein synthesis.

Amino Acid Sequence

The order of amino acids in a polypeptide chain, determined by the mRNA codons.

Translocation

The movement of the ribosome along mRNA during protein synthesis.

Active Protein

A fully synthesized protein that has completed translation and is functional.

Inactive Protein

A protein that cannot perform its function, often due to mutations or errors in synthesis.

Transcription

The process of synthesizing RNA from a DNA template.

Codon Assignment

The mapping of specific codons to their corresponding amino acids based on experimental data.

Post-transcriptional Modification

Chemical modifications that mRNA undergoes after transcription and before translation.

UAA, UAG, UGA

The three stop codons that signal the end of translation.

Methionine (Met)

The amino acid specified by the start codon, AUG.