Chapter 13 Flashcards
What is a restriction enzyme?
A protein that cuts DNA into fragments at specific places called restriction sites. If you want to combine two different DNA strands together you need to use the same restriction enzyme bc it only cuts at specific locations.
What is a plasmid?
A small circular DNA molecule that is found in bacterial cells. Makes for a really good vector because it has multiple restriction sites
Simple steps to clone a gene
- Cut DNA into fragments using restriction enzymes
- Paste DNA fragments into a vector (thats DNA has been cut by the same restriction enzymes so they will stick together with ligase)
- Allow to reproduce
Palindromic DNA
DNA that’s nucleotide sequence reads the same on both strands
5’ GAATTC 3’
3’ CTTAAG 5’
What is the polymerase chain reaction (PCR) used for?
To make more copies of a specific section of DNA. This is done by heating a mixture of original DNA with primers to unwind it. As it cools, the primers will stick to the open strands of DNA and create new side strands. Therefore, every time PCR is preformed the amount of DNA doubles.
What is a DNA Microarray?
It allows the expression of many if not all the genes in a genome to be compared side by side.
This is done by using cDNA to make a reverse DNA strand from RNA and dying each strand from each type of cell a certain color. The dyes go into a palette and depending on the gene strand on each spot (probe), certain complementary dyes will stick to certain spots. That way you can tell instantly what gene is expressed more in each type of cell.
How does gel electrophoresis work?
DNA is negatively charged. As a positive charge in put on the gel, the DNA will try to move away from it. The smaller the DNA the easier it can move through the gel, so normally smaller DNA moves further.
How does whole genome sequencing work?
It fragments entire chromosomes, amplifies DNA by PCR, determines the sequence of a short piece of DNA, then it reconstructs the genome using software.
Most modern and comprehensive genetic test now available
How does the Sanger sequencing method work?
It uses PCR to copy DNA, and adds a dyed dideoxynucleotide (its missing the 3’ OH so nothing can bind after it) to stop transcription. The new DNA strands are arranged into shortest to longest and a computer is used this to figure out the sequence of the template DNA
