1. Biotechnology Nicole & Ahlina P2
Bacteria, Viruses, and Genetic Engineering
Nicole & Ahlina P2

2. Bacteria: How does bacteria become resistant to antibiotics?
Images: 1. 2.
How does bacteria become resistant to antibiotics?
Efflux pumps pump antibiotics of the cell.
Prokaryote (bacteria) makes enzyme to degrade.
Bacteria’s enzyme can change the structure of the bacteria = changes its function.

3. Bacteria: Three reasons why organisms are resistant:
Naturally resistant or inherited
Acquired Resistance
Random Mutations
Vertical Gene Transfer: when an organism receives genetic material from its ancestors or parents.
Naturally resistant or inherited: the prokaryote might have been born without the proper cellular structures (transport system, membrane receptors, etc.) needed for the antibiotic to be effective.
Acquired Resistance: when organisms gain resistance from another source.
Required mutations: when organisms or bacteria developed resistance when exposed to an antibiotic.

4. Bacteria: Horizontal Gene Transfer:
Transformation
the update of naked DNA (usually a plasmid) by a prokaryote
Griffith mice experiment
Transduction
viral transmission of genetic information
Hershey/ Chase sulfur experiment
Conjugation
One bacterium gives resistance to another bacterium.
Sex pilus and mating bridge
Transposition
Movement of DNA segments within and between DNA molecules
“Jumping Genes” and Retrotransposition
Plasmid: genetic structure in cell that replicates independently of chromosomes (small and circular double strand DNA in cytoplasm)
Transformation: change in the geno/phenotype by incorporating foreign genetic material to make a recombinant cell ….example is the Griffith mice experiment ( S=killer, R=useless virus...mice given heat killed S virus injected into R virus die)
Transduction: virus takes over bacteria … hershey and chase sulphur( radioactively labeled the proteins on a phage and the dna on other phages and made them attack bacteria. Blended it together and found that the dna was found inside the blended bacteria while the proteins were found outside of the bacteria)
Conjugation: sex pilus pulls that bacteria together then mating bridge forms and genetic info shared
Transposition: dna segments are “cut/paste” and “copy/pasted” to different parts of the sequence. Jumping genes in corn (McClintock). Reverse transcriptase used to turn RNA into DNA that is inserted into the sequence.
Use of RNA increases genetic variety as it is more unstable

5. Viral: Phage: virus that infects bacteria
Discovered by Beijerinck when he found that the diseased tobacco were infected by something smaller than bacteria.
Differences in viruses:
All have: consist of nucleic acid and proteins, capsid coat, genetic material (DNA or RNA)
Differences: some have membrane that protect the capsid, some have glycoproteins for disguise, all have different shapes (structure=function)
Capsid coat made of capsomeres
Phages include tail sheaths and tail fibers

6. Viral: Viral Reproduction: Lysogenic vs. Lyctic
Phages that replicate only via the lytic cycle are known as virulent phages while phages that replicate using both lytic and lysogenic cycles are known as temperate phages.
Viral Reproduction: Lysogenic vs. Lyctic
Lytic: Phage injects genetic material into bacteria and takes over so that the viral DNA replicates and the bacteria transcribes viral mRNA that is then translated into the proteins that the virus needs (Capsids, tail, etc.) It eventually lyses(explodes) and the viruses escape to reproduce elsewhere.
Lysogenic: Viral DNA injected into bacteria and hides in genome and are multiplied as the bacteria copies its genome .This dormant cell is a prophage.

7. Viral: Reproduction of Viruses increase rate of evolution:
1.Viruses have highly efficient replicative capabilities that allow for rapid evolution and acquisition of new phenotypes.
2.Virus replication allows for mutations to occur through usual host pathways.
3.RNA viruses lack replication error-checking mechanisms, and thus have higher rates of evolution.
Related viruses can combine/recombine information if they infect the same cell.
4.Retroviruses that infect animals turn DNA into RNA using reverse transcriptase. EX: HIV

8. Viral:
Plant viruses usually have RNA genomes and they can be horizontally transmitted through the cell wall or vertically transmitted from parents.
Viroids are small, circular RNA molecules that can replicate within the host cell, but do not encode proteins.They cause disruptions in the regulatory systems that control plant growth
Prions are infectious proteins that cause brain diseases in mammals. They “reproduce” by turning healthy proteins into infectious proteins (prions). Some diseases caused by prions are Creutzfeldt-Jakob disease in humans, mad cow disease, and scrapie in sheep.

9. Genetic Engineering:
Biotechnology is the manipulation of natural biological processes to fill societal needs.

10. Genetic Engineering:
Transgenic examples: HGH deficiency, Golden Rice, and Reproductive Insulin
Cloning: and Organismal
Transgenic:
Human growth hormone originally extracted from pituitary gland of dead people until we began to inject the HGH into plasmids that would be taken up by bacteria that reproduce until we have the necessary HGH supply.
Insulin from pancreas and developed similarly to HGH using E.Coli, safflower, and yeast
Golden Rice is a GMO that contains beta carotene which supplies Vitamin A to people.
Cloning:
A clone is an exact genetic copy.
Cloned DNA using the Polymerase Chain Reaction, cloned cells using tissue cultures and stem cell lines.
Whole organisms: Plants have been cloned for years and animals (sharks) have cloned naturally using parthenogenesis(creating asexual offspring)

11. Genetic Engineering: Reprogramming: Stem Cells and iPS Cells
•When a sperm meets an egg, the resulting zygote is totipotent. The inner cell mass, the source of “embryonic stem” cells, are pluripotent.
•Totipotent cells have the ability to create a whole organism, or at least all different types of tissues.
•Pluripotent cells can only give rise to most types of tissues, and definitely NOT a whole organism.
Forensic: PCR and Electrophoresis
Stem Cells:
Controversial as they come from embryos
Can be used for tissue/ organ regeneration and to treat diseases such as heart disease and leukemia.
Plant cells are totipotent, meaning that they are essentially capable of anything
iPS=induced pluripotent stem cells splice a differentiated somatic cell with a reprogramming gene which makes the cell pluripotent. Eliminate need for embryoes.
Forensic:
used to discover parentage, criminals, and identify people
Gel electrophoresis sees if DNA is similar and if it matches
PCR: Takes a small amount of DNA and multiplies it
Analysis is for short tandem repeats which match

12. Go to kahoot.it and put in the Pin:
LET’S PLAY KAHOOT!
Go to kahoot.it and put in the Pin:
1ac0014d0b61