Translation and Proteins

Translation

The biological polymerization of amino acids into peptide chains, requiring amino acids, mRNA, ribosomes, and tRNA.

Ribosome

An organelle used in translation, playing an essential role in the expression of genetic information, made from rRNA.

rRNA

A form of RNA that builds ribosomes and performs the central catalytic functions associated with translation.

Svedberg Unit (S)

A subunit of the ribosome.

Ribosomal DNA (rDNA)

The genes that build rRNA, present in clusters with tandem repeats separated by noncoding spacer DNA.

Spacer DNA

Genetic material that separates different clusters of rDNA.

45S transcription units

Transcribed as a precursor to rRNA, processed into three mature rRNAs: 18S, 5.8S, and 28S.

tRNA

RNA that adapts genetic information in mRNA to corresponding amino acids, containing anticodons and carrying amino acids.

Anticodon

Part of tRNA that complementarily base-pairs with the codon in mRNA.

Charging

The process of linking the appropriate amino acid to the tRNA.

Aminoacylation

tRNA charging, the process of linking an amino acid to tRNA before translation.

Initiation Factor 3 (IF3)

Binds to 30S to prevent premature binding of 50S during the initiation of translation in prokaryotes.

70S

The structure formed when 30S binds to 50S, forming a complete initiation complex.

Shine-Dalgarno sequence (AGGAGG)

In prokaryotes, the sequence that 30S binds mRNA to, preceding the AUG start codon.

Peptidyl transferase

A function of 23S rRNA that catalyzes peptide bond formation between amino acids.

Termination

The process that ends translation, signaled by stop codons UAG, UAA, and UGA.

GTP-dependent release factors

Stimulate hydrolysis of polypeptide from peptidyl tRNA during termination.

Polysome

mRNA with several ribosomes translating it at once, allowing for efficient translation.

Cap-dependent translation

Eukaryotic translation that involves the m7G cap on the 7' end of mRNA.

Ubiquitin ligase

Attaches ubiquitin to misfolded proteins in eukaryotes.

Denaturation

When a protein loses its 3D structure and can lead to loss of biological activity.

Chaperones

Proteins that mediate the folding of other non-spontaneously folding proteins.

Enzymes

Proteins that increase the reaction rate of spontaneous reactions by lowering activation energy.

Catabolism

The process that degrades larger molecules into simpler ones and releases chemical energy.

Anabolism

The synthetic phase of metabolism, building molecules from smaller ones and using chemical energy.

Auxotrophy

The inability of an organism to synthesize a particular organic compound required for its growth.

Sickle Cell Anemia

Caused by a point mutation in hemoglobin, resulting in altered red blood cell shape.

Transcription factors

Proteins that regulate gene expression.

Proteosome

A large protease complex that degrades proteins flagged by ubiquitin.

Collagen/Keratin

Proteins important for structural integrity in skin and connective tissues.

Actin/myosin

Contractile proteins found in muscle tissue.

Immunoglobulins

Proteins that function in the immune systems of vertebrates.

Hemoglobin/Myoglobin

Proteins that transport oxygen required for cellular metabolism.

Cotranslational folding

The process whereby proteins begin to fold into their 3D conformation during translation.

Posttranscriptionally modified bases

Something contained in tRNAs structure, present after transcription of it and occurs as a result of cleaving a larger precursor

Cloverleaf Structure

What tRNA looks like

CCA Sequence

Where the amino acid is covalently linked to in tRNA, at the 3’ end