Midterm study Flashcards
Human genome
complete set of nucleic acid sequences to code for a human (codes for a human)
3 fundamental discoveries for the human genome
1) Restriction endonucleases
2) Cloning techniques
3) Synthesis of specific probes
Restriction endonucleases:
Enzymes cleave(cut) long DNA strands into many smaller fragments at specific cut sites
Bacteria produces restriction enzymes (EX. EcoRI)when virus adds its DNA into the enzyme
They cut at restriction sites that correspond to the enzyme. 4-6 base pair stretches
Sticky ends: leave some bases without their complementary base pairs making “sticky ends” so that they can re-stick easier
Blunt ends: cut straight down middle
Palindromes:
same back and forth (read same 5’ to 3’ as 3’ to 5’)
Cloning techniques
Combine DNA and introduce to new organism to amplify or increase amount
Introduce a foreign DNA molecule into a replicating cell allowing amplification (make many copies of the foreign DNA that is now tagging along the replication process)
Cloning VECTORS:
a specialized plasmid that has been engineered to act as a carrier or a vehicle that transfers specific foreign genes into the host cells (car that drives the foreign DNA into the host cell)
EX. viral, bacteria, yeast
Cloning techniques STEPS
- Restriction enzyme digests/cuts
- Target gene is joined/connected/stuck to at the cut
- Recombined into plasmid & can now transport into a host cell/put into an environment that can grow !!!!!Either host cell OR pcr!!!!!!
Prokaryotic Plasmids:
smaller circular piece of DNA that naturally exists. extra-chromosomal DNA molecule that replicates independently.
Polymerase Chain Reaction PCR:
where you amplify the specific target gene using science(laboratory technique) (In vitro(in test tube) amplifying technique AKA no host cell required)
Denaturing: template strand is heated up and double DNA strand breaks
Annealing: lower temp & primer is added
Extension: gives proper environment to grow by increasing the temp a bit
Advantages of PCR
Fast
Only need trace amount (a bit) of DNA to make a lot
Disadvantages of PCR
Need to know exact sequence of DNA that you want to amplify
When to use PCR in real life?
Viruses have long latency(showing symptoms) period and are difficult to detect early, can use to see it before symptoms show up
Gel electrophoresis:
- Large molecules travel less because heavy & small molecules travel more because light
- DNA= negatively charged so attracted to positive side which is further away from the probes
- Use stains or probes(markers) to visualize
Synthesis of specific probes
Allow identification and manipulation of specific DNA sequences
Probe:
sequences we made to then stick onto DNA so we can see it, a way to detect if something/a sequence is showing up/appearing
Complimentary to the gene of interest
tRNA
Transfer RNA
what carries the aminoacid and what connects to the aminoacyl site in translation
mRNA
Messanger RNA
What copies the code from the DNA in the nucleus by transcription, and sends the message of the codons to then go through translation
rRNA
Ribosomal RNA
The ribosomal subunits that help in translation
Types of mutations:
- Silent mutation→ the codon (3 letters) that had the change of 1 letter(nucleotide) still codes for the SAME amino acid
- Missense Mutation → the codon (3 letters) that had the change of 1 letter(nucleotide) codes for a DIFFERENT amino acid
- Nonsense Mutation → the codon (3 letters) that had the change of 1 letter(nucleotide) codes for a STOP/TERMINATION codon
Silent mutation
the codon (3 letters) that had the change of 1 letter(nucleotide) still codes for the SAME amino acid
Missense Mutation
the codon (3 letters) that had the change of 1 letter(nucleotide) codes for a DIFFERENT amino acid
Nonsense Mutation
the codon (3 letters) that had the change of 1 letter(nucleotide) codes for a STOP/TERMINATION codon