Biotechnology Flashcards
what is biotechnology
the use of living organisms or substances from a living organism that has developed a useful purpose (medicine, agriculture, environment)
who found the first restriction enzyme
Hamilton smith (HINDII)
recombinant DNA
creating a fragment of DNA composed of two samples obtained from different sources. or analyzing and altering genes and their respective proteins
the function of restriction enzymes
molecular scissors (only cut specific base pair sequinces)
- fragment and break bonds
requirements for restriction enzymes
the sequence must be 8 characters long and a palindrome
when a restriction enzyme is in use what reaction does it cause to break the phosphodiester bond
hydrolysis
sticky cut
both fragments have one extended side of DNA that is missing its complimentary base pairs
blunt cut
fragments are fully base-paired
Naming a restriction enzyme
based on the bacteria they originate from
first letter = initial of their genus category
second and third = initials of the species name
fourth= indicates the strain (of bacteria)
- a roman numeral at the end to indicate the order of discovery
purpose of restriction enzymes in bacteria
acts as an immune system
- recognizing foreign DNA and chopping it up
Methylases
an enzyme that adds methyl groups to the recognition site of the organism’s DNA so the restriction enzymes can identify their purpose
purpose of Methylases
so restriction enzymes have a way to determine foreign DNA from the cells own DNA
gel electrophoresis
the separation of charged molecules (DNA) through a gel meshwork on the basis of size
what charge does DNA have and what gives it its charge
negative- phosphate groups
process of gel electrophoresis
- a rectangular or square slab of gel is submerged into a buffer containing
electrolytes and agarose - connected to a power source (negative and positive charges at opposite ends)
- DNA is inserted via wells at the top of the slab
- an electrical current is run through the gel
- the negative electrons from the power source push the DNA fragments through the gel towards the positive end (like charges repel and opposites attract-push and pull)
- the smaller fragments go farther due to less resistance
Marker DNA
- developed in a lab to meet the exact specifications of the gene of interest
- placed into the slab as well and which ever fragment lines up with the marker is the gene of interest
staining
dye is used to stain the DNA inorder to help visualize the banding patterns
does DNA have color?
no
PCR
polymerase chain reaction
what is PCR
the creation of DNA sequences by repeated cycles of strand separation and replication
PCR process
- break the hydrogen bonds separating the strands by using heat, specifically raising the temp to 94-96 degrees Celcius
- lower temp to 50-65 degrees so primers can attach
- Taq polymerase (found in hot springs) is used to build the complementary strand for BOTH strands
- during this process, the temp must be raised to 72 degrees - then you repeat
- each cycle doubles the amount of DNA in the machine
CRISPR
Clustered regularly short palindromic repeats
- protein/RNA hybrid molecule
CRISPR natural applications
- acts as bacteria immune system, cutting up foreign DNA
CRISPR artificial applications
Genome editing
- the simplest, most versatile and precise method of genetic manipulation currently developed
who developed CRISPR
Jennifer Douna and ammanuelle charpenteir
how does CRISPR work
- Guide RNA (gRNA) is a small piece of pre-designed DNA that is inserted into the cell to target a particular gene of interest, usually about 20 base pairs long.
(complementary to the target DNA) - binds with cas9 guiding the enzyme to the correct part of the genome
- molecular scissors and a guide in one
after cas9 has cut out the targeted segment of DNA
the cell recognizes the damage done to the DNA and tries to repair it
- this can be done by the cell itself leading to random base pairs causing mutations (this can help identify what gene codes for)
- or scientist can pre-design a segment of DNA that matches the length of the hole and insert it into the cell
- this allows for the removal of unwanted genes/mutations and allows for the insertion of new genes
who discovered the CRISPR gene
yoshizumi Ishino in 1987
who discovered viral DNA within the crispr gene
Eugene Koonin 2007
who identified the importance of cas9 + tracrRNA
emmanuelle charpenteir in 2011
who determined the mechanism to create CRSPR using biochemistry
Jennifer Duodna 2013
who published the humanization and commercialization paper on CRISPR
Feng Zhang 2015
who made the first genetically modified humans
He Jiankui 2018
when did the two women responsible for cas9 win the nobel prize
2020
potential benefits of CRISPR
-develop safer medical treatments
- cure diseases
- work with stem cells
- application in plants
- help humans better understand themselves
