Translation and Proteins

Flashcards covering vocabulary from the Translation and Proteins lecture.

Translation Overview

Process where mRNAs bind to ribosomes, tRNAs string together amino acids, and ribosomes couple mRNA codons with tRNA anticodons.

Ribosomes

Composed of ribosomal RNA (rRNA) and proteins, facilitates the coupling between mRNA, translation factors, and tRNA.

P Site

Binding site for Peptidyl-tRNA

E Site

Exit site on the ribosome

A Site

Binding site for Aminoacyl-tRNA

Transfer RNA (tRNA)

RNA that transfers amino acids for polypeptide elongation, contains an anticodon and carries a specific amino acid.

Anticodon

Sequence of 3 nucleotides that bind to the codons of the mRNA.

Aminoacyl-tRNA synthetases

Enzymes that link tRNAs with their specific amino acids

Aminoacylation site

The location on the tRNA where the amino acid is linked.

Three stages of translation

Initiation, elongation, and termination.

Shine Dalgarno sequence

A nucleotide sequence upstream to the start codon that binds to the small ribosomal subunit during translation initiation.

Initiator tRNA

tRNA with a UAC anticodon that binds to the start codon (AUG).

Start Codon (AUG)

The start codon recognized by the initiator tRNA, which codes for methionine.

P site (peptidyl tRNA binding site)

Site where the initiator tRNA is located during translation initiation.

A site (aminoacyl tRNA binding site)

Ribosome site where a tRNA with an anticodon complementary to the mRNA codon enters during elongation.

E site (exit site)

Ribosome site where the uncharged tRNA enters and releases from the ribosome during elongation.

Translation Termination

Occurs when the ribosome's A site encounters a stop codon (UAG, UAA, or UGA).

Release Factor

Binds to the stop codon in the A site and breaks down GTP to release the polypeptide.

Polyribosomes/Polysomes

Multiple ribosomes actively translating a single mRNA molecule.

Kozak sequence (GCCGCC)

A sequence upstream of the start codon that aids in translation initiation in eukaryotes.

Chaperones

Folding proteins that some polypeptides bind to, to achieve proper conformation .

Signal Peptide

Amino acid sequence in the front end of proteins destined for the extracellular fluid or to the cell’s endomembrane system.

Signal-recognition particle receptors

Proteins in the ER membrane that recognize the signal peptide and channel the protein into the ER.

Translation

The process of making a protein.

Translation

The primary structure of a protein is formed during this process.

Nucleolus

The location in eukaryotic cells where ribosomes are made.

Post-translational modification

Enzymatic modification of proteins after translation, such as amino acid removal or modification.

Cytoplasm

The cellular location where ribosomal subunits bind to mRNA in eukaryotes.

Protein trafficking

The process by which proteins are directed to their correct location

Cytoplasm

The location within cells where all proteins are initially synthesized.

ER (Endoplasmic Reticulum)

The location signal peptides target proteins to.

Large ribosomal subunit

Peptide bond formation is catalyzed here.