Translation Flashcards
How are the introns removed from the DNA strand?
They are removed by splicing RNA precursors. The complex removes the introns and joins the adjacent exons to produce a mature mRNA. That can leave the nucleus through a pore and enter the cytoplasm to begin translation.
What is the start codon?
A U G
What are the three stop codons?
U G A
U A G
U A A
Where does transcription take place?
The mRNA strand leaves the nucleus and goes to the ribosome for translation.
What is Ribosomal RNA?
It makes the ribosome. Helps to read mRNAs message and assemble proteins.
What is transfer RNA?
Transfers amino acids to ribosome that are complementary to the mRNA.
What is snRNA?
Small nuclear RNA, forms complexes with proteins used in eukaryotic RNA processing.
What is miRNA/ siRNA
Micro RNA/ small interfering RNA, short - 22 base RNA sequences that bind to 3’ UTR target mRNAs and result in gene silencing
What is the function of messenger RNA?
Encodes the amino acid sequence of a polypeptide.
How does translation begin?
With the binding of the mRNA strand binding to the small ribosomal subunit upstream of the start codon. The type of amino acid is determined by the anticodon sequence by the tRNA. the first one will be met.
How does translation take place?
When complementary base-pairing occurs between a codon of the mRNA and the anticodon of the tRNA.
How does translation end?
Amino acids are brought until the entire mRNA is read. Each tRNA drops off one amino acid then goes into the cytoplasm to grab another. The ribosome bonds each amino acid together creating a polypeptide. Eventually the stop codon is reached and the final amino acid is added.
Describe a molecule of tRNA.
The look like a long clover-leaf shape. Each molecule has; an anticodon site with sequence of 3 unpaired bases that is complementary to codon in mRNA, an attachment site to bind to a specific amino acid, and a recognition site enabling correct amino acids to bind each tRNA.
What bond forms between the amino acids?
A peptide bond
How do cells protect themselves from viral infection?
They protect themselves by inhibiting viral protein synthesis. Induction and action of interferon.
Why are some strains of staphylococcus aureus resistant to erythromycin?
Certain strains of staphylococcus can carry a plasmid that encodes an RNA methylase. This RNA methylase converts a single adenosine residue in 23S rRNA to N6-dimethyladenosine. this is the site of action of erthromycin, linomycin and clindamycin. N6-dimethyladenosine blocks the action of these antibiotics. The organism that produces erythromycin has its own RNA methylase and thus is resistant to the antibiotic it makes.
