Bio 93 Lecture 27 Flashcards
biotechnology
manipulation of organisms or their components to make useful products
DNA technology
applications affect everything from agriculture, to criminal law and medical research
Main techniques of biotechnology? (6)
-DNA sequencing
-Gene cloning
-PCR amplification
-Expressing genes
-Analyzing gene expression
-Gene editing
Main applications of biotech? (5)
-Agriculture
-Medicine
-Environmental cleanup
-Ancestry
-Forensics
Human Genome Project
(2007) sequencing of the entire Human Genome
recombinant DNA
often combined IN VITRO (into the same DNA molecule)
DNA Cloning
-uses plasmids in bacteria
plasmids
small circular DNA that replicate separately from bacterial chromosome, shared between bacteria cells, used in DNA Cloning
Why are plasmids used in cloning?
-readily obtained
-easily manipulated
-easily introduced into other bacterial cells
-rapidly multiply
Process of cloning a gene
1) gene inserted into plasmid
2) plasmid put into recombinant bacterial cell
3) host cell grown in culture to “clone” gene of interest
4) proteins expressed & copies of gene extracted for application
cloning vector
the original plasmid, can carry foreign DNA into a host cell & replicate it
What cuts out the DNA?
restriction enzymes
Why isn’t the bacteria’s own DNA cut?
methylated
Where do restriction enzymes work?
Restriction sites
What do restriction enzymes produce?
“sticky ends”
What is the role of DNA ligase in DNA cloning?
seals bonds between restriction fragments (binds sugar phosphate backbones)
CRISPR stands for
Clustered Regularly Interspaced Short Palindromic Repeat
What does cas9 do?
creates novel “spacer” from new viruses and adds to CRISPR
What is cas9?
RNA-guided DNA endonuclease (guided by guide RNA- gRNA or crRNA)
Genome editing
1) cas9 protein & guide RNA bind & introduce in cell
2) guide RNA binds to target gene
3) cas9 cuts DNA on both strands
4) broken strands are repaired (knocked our or switched our for a normal copy of the gene)
What animal was cloned in 1997?
Dolly the sheep, suggested clones were not always identical to donor`
Problems with animal cloning
- only a small number of embryos were viable
- many epigenetic changes
stem cells
unspecialized, can reproduce indefinitely and differentiate into diff. cell types
embryonic stem cells
–> all cell types
adult stem cells
replace non-reproducing specialized cells (limited)
pluripotent stem cells (IPS)
inserting the correct combination of transcription factors can reprogram cells back into stem cells, used to treat sickle cell disease
