Quiz 8 Flashcards
Diphtheria toxin kills eukaryotic cells by affecting translation. More specifically, the toxin prevents movement of tRNAs from the A site to the P site of the ribosome. Predict what the result(s) of this inhibition would be.
- Protein synthesis will continue, but at a slower rate.
- New tRNAs will not be able to enter the ribosome.
- Protein synthesis will be inhibited because the 1st tRNA molecule will not be able to bind to the start codon.
- Protein synthesis will be interrupted because the peptide chain is inhibited from growing.
- New tRNAs will not be able to enter the ribosome.
- Protein synthesis will be interrupted because the peptide chain is inhibited from growing.
Which DNA strand is synthesized continuously?
leading strand
What is the initial target of RNA polymerase?
the promoter
What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands?
DNA is flexible
What is the basic function of the lac operon?
To code for enzymes involved in catabolizing lactose.
A mutation that affects the genotype of the organism but not the phenotype is called a
silent mutation
During elongation, how is the RNA synthesized?
5’ to 3’
What kind of bond is formed when two amino acids join together?
a peptide bond
During infection, C. diphtheriae expresses a variety of genes that are used to establish infection and cause disease. One of these genes encodes for diphtheria toxin. Expression of the toxin requires the genetic information contained in DNA be converted into protein. The 1st step in this process is transcription, in which DNA is converted into mRNA. The following is a short piece of the DNA sequence for diphtheria toxin (written 5’ to 3’): TAA GCG TAG AAC TTG. Which of the following sequences represents the mRNA (written 5’ to 3’) that will be generated from this template DNA sequence?
CAA GUU CUA CGC UUA
How does the ribosome know if the entering charged tRNA is correct?
The anticodon on the tRNA base pairs to the codon on the mRNA.
