prac 3 Flashcards
Bacteria use operons to regulate gene expression. Explain what happens in the try operon when tryptophan is ABSENT in the environment.
when tryptophan is NOT present, the repressor protein is inactive and does NOT bind to operator
RNA polymerase is able to bind to promoter region and transcription of genes that are responsible for the biosynthesis of tryptophan can continue until there’s a lot , causing it to bind to the repressor and stop production
how does gel electrophoresis work
goal is to separate DNA by size, which can then be sequenced
-uses ethidium bromide to stain, so you can see DNA
-uses fragment DNA markers of a known length to determine length of the other DNA
-DNA is negatively charged and placed on the start end of the gel which has a negative electrode so once a current starts the DNA is repelled from the negative electrode and moves toward the positive electrode
-smaller DNA moves faster thru the agarose gel compared to larger DNA which means the closer it is to the positive, the shorter it is
-allows you to distinguish by size
alternative splicing and how does this relate to humans having the ability to make 100,000 different proteins from only 20000 genes
-utilizing a different combo of exons from a gene to make an mRNA
-relates to us, as it allows humans to build a variety of different proteins from just a single line of mRNA which can help with cellular processes
