6.1 Biotechnological Tools and Techniques
Retrieved from simzymes.com
Restriction enzyme: an enzyme that cuts a strand of DNA at a specific nucleotide sequence (recognition sites)
· Originally found in bacterial cells (bacteria and archaea) as a protective method against viral invasion
· Many recognition sites are palindromic, an inverted repeat palindrome being most significant in biological processes (when a sequence of DNA is palindromic across the two DNA strands in the double helix)
Ex: ACGTACGT
TGCATGCA
· Each enzyme has a specific shape that allows it to move along the helix until it finds it’s specific recognition site to cut the DNA strand
· A cut that produces “sticky ends” cuts each strand of the double helix at a different point
Ex: A|CGTACG
TGCATG|C
· A cut that produces a “blunt” end cuts each strand of the double helix at the same point
Ex: AT|ACGT
TA|TGCA
· Originally found in bacterial cells (bacteria and archaea) as a protective method against viral invasion
· Many recognition sites are palindromic, an inverted repeat palindrome being most significant in biological processes (when a sequence of DNA is palindromic across the two DNA strands in the double helix)
Ex: ACGTACGT
TGCATGCA
· Each enzyme has a specific shape that allows it to move along the helix until it finds it’s specific recognition site to cut the DNA strand
· A cut that produces “sticky ends” cuts each strand of the double helix at a different point
Ex: A|CGTACG
TGCATG|C
· A cut that produces a “blunt” end cuts each strand of the double helix at the same point
Ex: AT|ACGT
TA|TGCA
6.2 Genetic Engineering
Retrieved from cliffsnotes.com
Recombinant DNA: a DNA sequence synthesized in the laboratory that doesn’t occur naturally – DNA sequences can come from many different sources
· Recombinant DNA can be inserted into a host cell and be replicated as the cell undergoes natural division
o Remember: A host cell is a normally functioning cell that receives a strand of foreign DNA and replicates it with the replication of its own DNA
· Restriction enzymes are used to splice DNA from different sources, while DNA ligase is the enzyme used to reattach the spliced nucleotides, forming a new DNA sequence
Vectors: a DNA molecule used to transfer genetic information from one cell to another
· The purpose of a vector is to isolate, multiply, or replicate a desired trait in a host cell
· The vector generally contains a “backbone” DNA sequence that contains the genetic code for a desired trait, as well as an insert gene, that helps the cell recognize and replicate the new genetic sequence
· Inserting a vector into a bacterial cell is called transformation
· Inserting a vector into a eukaryotic cell is called transfection (inserting a viral vector into a eukaryotic cell is called transduction)
Common types of vectors:
· Plasmids: a double-stranded, circular sequence of DNA that can replicate on it’s own in a host cell
o Plasmids are simply circular strands of DNA that can be modified to contain different genetic sequences and express different genes
· Viral Vectors: non-infectious viral DNA or RNA that contains viral promoters, allowing for translation to occur in replication
· Recombinant DNA can be inserted into a host cell and be replicated as the cell undergoes natural division
o Remember: A host cell is a normally functioning cell that receives a strand of foreign DNA and replicates it with the replication of its own DNA
· Restriction enzymes are used to splice DNA from different sources, while DNA ligase is the enzyme used to reattach the spliced nucleotides, forming a new DNA sequence
Vectors: a DNA molecule used to transfer genetic information from one cell to another
· The purpose of a vector is to isolate, multiply, or replicate a desired trait in a host cell
· The vector generally contains a “backbone” DNA sequence that contains the genetic code for a desired trait, as well as an insert gene, that helps the cell recognize and replicate the new genetic sequence
· Inserting a vector into a bacterial cell is called transformation
· Inserting a vector into a eukaryotic cell is called transfection (inserting a viral vector into a eukaryotic cell is called transduction)
Common types of vectors:
· Plasmids: a double-stranded, circular sequence of DNA that can replicate on it’s own in a host cell
o Plasmids are simply circular strands of DNA that can be modified to contain different genetic sequences and express different genes
· Viral Vectors: non-infectious viral DNA or RNA that contains viral promoters, allowing for translation to occur in replication