Chris Lee

The Cooper Union for the Advancement of Science and Art · Mechanical Engineering

If I wanted to introduce a foreign protein into the human stomach without it getting cleaved up by proteases such as trypsin, how would I do so?

Since bacteria produced a single RNA polymerase, is T7 RNA polymerase the single RNAP produced in Lemo cells? Does T7 polymerase require a specific binding sequence or can it bind non-specifically to most promoters?

I know that several genes come one after the other under a single promoter in an operon, but what is exactly between those genes? Does the start codon of the second ORF come right after the ORF of the first gene? If there is a specific example with the dna sequence, that would be great.

Also, does an operon always require an operator?

Question 1: For example, if 70 bps of complete homology exist between a fragment and host chromosome (in let's say E. coli), will all 70 bp's be exchanged between the two DNA molecules?

Question 2: Will each strand go through recombination as in holiday junction etc...?

Another way of phrasing this question would be: Is there a chance that a transformed plasmid with homologous sequences does not recombine with the chromosomal DNA? If so, will a cell still be selected due to the plasmid vector containing the selectable marker? Accordingly, if previous statements are true, would one have to run multiple samples through a gel and select the colony without the plasmid (my guess)?