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Flashcards in Translation Deck (11)
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1

tRNA translates the codon into

the correct amino acid

2

Ribosomes

are the factories where translation occurs

3

3 stages of translation

Initiation
Elongation
Termination

all require GTP

4

Initiation

the first stage of translation

in prokaryotes occurs when the 30S ribosome attaches to the Shine Delgarno sequence and scans for a start codon; it lays down N - formylmethionine in the P site of the ribosome

in eukaryotes occurs when eh 40S ribosome attaches to the 5' cap and scans for a start codon; it lays down methionine in the P site of the ribosome

5

Elongation

involved the additions of a new ammoniacal - tRNA into the A site of the ribosome and transfer of the growing polypeptide chain from the tRNA in the P site to the tRNA in the A site. The now uncharged tRNA pauses in the E site before exiting the ribosome

6

Termination

occurs when the codon in the A site is a stop codon; release factor places a water molecule of the polypeptide chain and thus releases the protein

7

Posttranslational modifications include:

- folding by chaperones
- formation of quaternary structure
- cleavage of proteins or signal sequences
- covalent addition of other biomolecules

8

Phosphorylation

addition of phosphates by protein kinases to activate or deactivate proteins

9

Carboxylation

addition of carboxylic acid groups, usually to serve as calcium binding sites

10

Glycosylation

addition of oligosaccharides as proteins pass through the ER and Golgi apparatus to determine cellular destination

11

Prenylation

addition of lipid groups to certain membrane - bound enzymes