Chapter 11: Translation Flashcards
production of a protein from the information in an mRNA
translation
provides the physical link that decodes mRNA into protein
tRNA (transfer RNA)
tRNAs read the mRNA by base-pairing 3 nucleotides: region in tRNA is the (1), while the region on the mRNA is the (2)
- anticodon
- codon
amino acids are attached to tRNAs by ()
aminoacyl-tRNA synthetases
Protein synthesis is carried out by a large molecular machine ()
ribosome
ribosomes have ()
2/3 RNA (rRNA) + 1/3 protein (r-proteins)
the (1) subunit of the ribosome deciphers the mRNA and the (2) subunit mediates the chemical bond formation
- small
- large
ribosomes move () along an mRNA molecule
processively (5’ to 3’)
Proteins are synthesized at a rate of about (1) amino acids per second, with
an error rate of about (2) per residue
- 15
- 10-3 to 10-4
translation factors are often () that use the energy of () hydrolysis
GTPases, GTP
4 main stages of translation
- initiation
- elongation
- termination
- ribosome recycling
two essential processes of transfer RNAs (tRNAs)
- decipher mRNAs
- carry amino acids
(): tRNA structure has four regions of double-stranded RNA, including 3 stem-loops
clover-leaf pattern
2D structure of tRNA: 5’ and 3’ ends base pair and form the (1), with a conserved (2), which is the attachment point of the amino acid
- acceptor stem
- 3’ CCA tail
2D structure of tRNA: the () has 3 nucleotides that base pair with the codon in mRNA in an antiparallel fashion
anticodon loop
a folded tRNA has an () structure (3D)
L-shape
the bases in a tRNA anticodon (position 34-36) are typically stacked on top of each other in a structure called a () -> anticodon loop positions the nucleotides to effectively base pair with mRNA
U-turn
A () (e.g. base Y) occurs just after the anticodon (typically position 37, found in anticodon loop), to prevent this from base-pairing with the codon in mRNA.
hypermodified purine
hypermodified purine after the anticodon aligns the codon and anticodon properly -> critical for ensuring high fidelity of ()
decoding
in tRNA, () is typically in position 34 (in anticodon loop) is important for wobble pairing
inosine
the DHU (D) loop in tRNA is named after the () in the loop
dihydrouridine (D)
the TpsiC (T) loop has (1) and (2) in the T loop
- ribothymidine (T)
- pseudouridine (psi)
Each triplet codon specifies a single amino acid (1) or no amino acid (2).
- sense codon
- stop codon; nonsense codon
() codons signal the end of the protein-coding region of the mRNA
stop