Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions.

Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions. Lecture: Phenotypic Classifcation. Complete Powerpoint review of lecture At the end of the lesson, write for 2 minutes about what you learned in Lesson 4.

Microbial evolution http://www.youtube.com/watch?v=XawzIjX72U0
4 parts of video

Lesson 4 What is a species?
A species is defined as a population that can naturally interbreed and produce fertile offspring, and that is reproductively isolated from other species. Right! Well, maybe not……..

Species Concept - Microbiology
A bacterial species is a prokaryote whose 16S ribosomal RNA sequence differs by no more that 3%. That is, at least 97% of the rRNA sequence is identical in a bacterial species. A bacteria whose rRNA differs by more than 3% usually turns out to be a different species.

Species Concept- Microbiology
Prokaryotes do not fit the biological species concept because they are haploid and reproduce asexually. They cannot produce “fertile offspring” like plants and animals can. In microbiology, evolutionary (molecular)chronometers measure evolutionary change. In other words, differences in nucleotide or amino acid sequences of functionally similar (homologous) macromolecules are a function of their evolutionary distance. The greater the number of differences in a sequence the more distantly related the two species are.

Species Concept - Microbiology
Molecular Chronometers The chronometer must be present in all groups being classified and it must be functionally homologous (not many sequence differences). The following genes and proteins are most frequently used to classify bacteria. - ribosomal RNA - ATPase proteins (synthesize ATP)  - RecA (enzyme facilitates genetic recombination) - Certain translation proteins.

Species Concept- Microbiology
Ribosomal RNA is the most widely used chronometer for identifying bacterial species : - It is relatively large. - Universally distributed - Has many nucleotide sequences that are conserved. 16S rRNA are part of the small subunit (SSU) of the ribosome; used to classify prokaryotes.

Evolutionary Tree - Microbiology
Phylogenetic Tree of Life - rRNA

Three Domains - Microbiology
Bacteria At least 40 phyla of bacteria in this domain. Most of the phyla are related from a phylogenetic standpoint but have little in common in terms of phenotype. Proteobacteria contain species which are the ancestors of mitochondria.

Archaea 4 phyla in this domain Contain extremophiles - Hyperthermophiles: live in high temperatures. - Methanogenic : produce methane. - Extreme halophiles: live in high salt environments. Contains Ignicoccus, bacteria with the smallest genome.

Eukarya rRNA phylogeny based on 18S rRNA. Four kingdoms: Protista, Fungi, Plant, and Animal. Range from single cell to complex multi-cell organisms. Rapid diversification of Eukarya was tied to changes in oxygen levels on earth.

Phenotypic Classification-Bacteria
Working microbiologists use phenotypic commonality in identifying bacteria. Most frequently these phenotypes are: Cell shape Cell wall structure Cell respiration Growth factors Colony morphology

Cell Shape There are 4 bacterial shapes: - Cocci (coccus s.) or round - Bacilli (bacillus s.) or rod shaped - Spirillum or cork screw shaped - Filamentous or like jelly beans in straw

Phenotypic Classification- Bacteria
Cocci Round shape Examples -Staphlococcus  (in clusters) -Streptococcus (in chains) 

Phenotypic Classification - Bacteria
Bacilli Rod shaped Examples - Bacillus anthracis  (agent in anthrax) - Escherichia coli  (used in biotechnology)

Spirillum Cork screw shape Example - Treponema pallidum (agent of syphilis)

Filamentous Jelly beans in straw Example -Leptothris discophora (aquatic bacteria uses iron the way we use oxygen).

Phenotypic Classification -Bacteria
Composition of Cell Walls Difference in cell wall structure becomes clear when a technique called the Gram stain is used. Bacteria on a glass slide are stained first with a purple dye; the slide is rinsed with ethanol, and then a red counter stain is applied. If bacteria remain purple = Gram positive. If bacteria turn red = Gram negative.

 Gram + cocci Gram – rods 

Phenotypic classification
All bacteria have a cell membrane and a cell wall composed of peptidoglycan.

Gram positive bacteria have their cell membrane and a simple but thick cell wall of peptidoglycan . Peptidoglycan gives shape to the cell. Gram negative bacteria have their cell membrane and a thinner layer of peptidoglycan plus an outside layer of lipopolysaccharides. Lipopolysaccharides make gram negative organisms more threatening than gram positive organisms.

Cell Respiration There are 3 types of cell respiration( synthesis of ATP): - Aerobic: Use oxygen for cell respiration. - Anaerobic: Cannot tolerate oxygen. Use fermentation - Facultative anaerobes: Can use or not use oxygen depending on availability.

Growth Factors Nutrient Source - Heterotroph: Consume energy from outside source. - Autotroph: Make and consume energy. Energy Source (Autotrophs) - Chemoautotroph : Use chemicals as energy source. - Phototrophs: Use light as energy source.

Colony morphology A single bacteria put onto a solid agar plate, if given sufficient nutrients, optimal temperature and pH, will multiply and form a colony. All members of the colony are genetically identical. Bacterial colonies of different species differ from one another.

To identify a colony, the following basic elements are noted. Form- What is the basic shape of the colony? Elevation - What is the cross sectional shape of the colony? Margin - What is the magnified shape of the edge of the colony? Surface - How does the surface of the colony appear? Opacity – Is the colony translucent, transparent, iridescent? Chromogenesis – pigmentation.

Phenotypic Classification
Form - Shape of the colony

Elevation – Cross sectional shape

Margin - Shape of the colony edge.

Opacity – Clear, Opaque, Iridescent Iridescent

Phenotypic Classification
Chromogensis - Pigmentation

Lesson 5 Visit the 3 websites noted on your handout to learn about prokaryotic structures and function. Respond to all questions. Next read the Powerpoint slides on prokaryotic structure and respond to all questions.

Prokaryotic structure
DNA in prokaryotes DNA is found in the - Nucleoid Region - Plasmids A typical prokaryote has one chromosome containing most of the genes in the cell. A few species of Bacteria & Archaea contain two chromosomes. The DNA is a double stranded circular molecule. Bacterial genomes contain from 500,000 base pairs to about 4 million base pairs, depending on the species..

Prokaryotic Structure
Plasmids Plasmids are genetic elements (DNA) that exist and replicate separately from the chromosome. Most are circular, some are linear. Many prokaryotes contain one or more plasmids. They range in size from 100 to 1,000 base pairs. Plasmid DNA can be exchanged among bacteria. For example, genes for antibiotic resistance are found on plasmids and one bacteria can transfer these genes to another bacteria. Bacterial plasmids play a role in recombinant DNA technology.

The differences between a bacterial chromosome and a plasmid: - Chromosomes carry many more genes than plasmids and the genes are essential to cellular function. Essential genes are called housekeeping genes. - Plasmids carry far fewer genes and are expendable because the genes are not necessary for growth under all conditions.

Restriction Endonucleases (Enzymes) Are naturally found in bacteria. When viruses invade bacteria, restriction endonucleases have the ability to cut up the foreign viral DNA. The possibility of viral infection plummets. Can be thought of as a bacterial immune system because the role of restriction endonucleases is to protect the bacteria. Bacteria can have more than one type restriction enzymes. Bacterial restriction enzymes play a role in recombinant DNA technology.

Lesson 6 Lab experiment to demonstrate effectiveness of antimicrobial soap. Lab: - Review the following videos for instruction in microbiological techniques. Pouring agar plates. Dilutions and spread plating Streaking plates Aseptic transfer Making smears Gram stains

Lab Day 1: Handwashing and plate innocculation
Day 2: Review Streaking for isolation video, collect data, and streak plates for isolation Day 3: Collect data, study colony morphology, and gram stain

Lesson 7 E.coli Lecture: - E.coli the organism and its use in biotechnology. - Pathogenic E. coli Read handout on pathogenic E.coli. Respond to questions. Class Review Case Study “Microbial Pie” Track the Epidemic

E.coli Escherichia coli
Gram negative rod normally found in the intestines of warm blooded animals. E.coli can benefit its host by producing vitamin K and by reducing numbers of pathogenic bacteria in the intestine.

E. coli E.coli is a hardy organism that is easy to culture and easy to manipulate in the lab. It is a model organism in biotechnology. Model organisms are extensively studied to understand biological phenomena and the information can be applied to other organisms. E.coli genome was one of the first to be sequenced in 1997.

E.coli Most economically robust area in biotechnology is production of human proteins. E.coli has played a major role in production of these proteins. Human genes for proteins can be cloned and inserted into plasmids in E.coli through recombinant DNA technology

E.coli E.coli is then grown in large bioreactors and it produces the protein of interest. Purification methods separate the target protein from the biological molecules in which it was produced. The proteins can then be used by humans.

E.coli The following proteins are manufactured via this technique:
Insulin For diabetes Human Growth Hormone For growth hormone deficiency Factor VIII For hemophilia Erythropoietin For stimulation RBC growth

E. coli Pathogenic vs. Non-pathogenic E.coli.
Most E.coli strains live commensally in the intestines of warm blooded animals. These strains are non-pathogenic. Non-pathogenic strains of E.coli strains are used in biotechnology research. Some E.coli strains are virulent and produce gastrointestinal disease. These strains are pathogenic.

E. coli Causes of virulence Toxicity
- Ability to cause disease by a preformed toxin. Toxin inhibits host cell function and kills host cell. Invasiveness - Ability of organism to grow in host cell tissue in such large numbers that pathogen inhibits host cell activity.

E. coli E.coli virulence Due to an enterotoxin, a type of exotoxin.
The enterotoxin is secreted by the bacteria and affects the cell membrane of intestinal cells. It makes the host cell membrane more permeable to chloride ions. As chloride enters the host cells, sodium and water leave the host cells. This causes diarrhea and abdominal pain. Virulent E.coli is acquired by eating contaminated food.

Lesson 8 Lecture: Natural gene transfer and recombination.
Whole class lecture: Gene transfer in prokaryotic organisms. Pantomime of gene transfer Case Study: Antibiotic resistance Read each section of case study. Respond to questions. In between each section of the case study, the whole class will have a discussion to clarify any of your concerns.

Gene Transfer and Recombination
Bacteria pass on their genetic material to the next generation asexually through binary fission. Many bacteria, however, have the capacity to physically exchange genetic material with other bacteria. There are 3 processes in which genetic material can be exchanged: Transformation Transduction Conjugation These 3 process are collectively referred to as lateral or horizontal gene transfer.

Transformation Is a process by which free DNA is incorporated into a recipient cell and brings about genetic change.

Do you remember the Griffith experiment?

Transformation If a bacterial cell is lysed, the DNA pours out. The bacterial chromosome then breaks apart into fragments with about 10 genes on them. Other bacterial cells that are competent can take up the DNA from the environment. Competency is genetically determined. The DNA enters the cell and is escorted through the cytoplasm by competence specific proteins to prevent degradation. DNA is then recombined (integrated) into the bacterial chromosome.

Transformation in Biotechnology In biotechnology procedures, the term transformation has a slightly different meaning. E.coli are poorly transformed under natural conditions. If you treat the organism with calcium ions and chill it, it becomes easily transformed. Transformation of this organism generally occurs in the plasmid.

Transduction DNA is transferred from cell to cell by a virus. Virus can transfer host cell DNA along with its own genetic material.

In transduction, any gene on a donor bacterial chromosome can be transferred to a recipient. A phage (virus for bacteria) enters the host cell and during a lytic infection enzymes responsible for packaging viral DNA sometimes package the host DNA accidentally. The resulting virus with a piece of the donor DNA is called a transducing particle. This transducing particle cannot go on to cause infection in a new cell. The DNA released is incorporated into a recipient bacterial cell chromosome.

Transduction

Plasmids revisited Before we learn conjugation, let’s review plasmids. Plasmids: Are genetic elements that replicate independently of the host chromosome. Are unessential, do not control vital cell functions. Are double stranded, mostly circular (some linear), structures with fewer genes than the bacterial chromosome. Of different types may be present in a cell and numbers of these types can vary. Called episomes can integrate into the bacterial chromosome.

Types of plasmids F (fertility) plasmid - most studied, results in the expression of sex pili. R (resistance) plasmids - contain genes that can build a resistance against antibiotics Col plasmids - which contain genes that code for bacteriocins that can kill other bacteria. Degradative plasmids, which enable the digestion of unusual substances. Virulence plasmids- which turn the bacterium into a pathogen.

Conjugation Is a process of genetic transfer that involves cell to cell contact. A conjugative plasmid uses this process to transfer a copy of itself to a new host. The process involves a donor cell and a recipient cell.

Conjugation (using the F plasmid as an example) The F+ cell has the plasmid and the ability to donate it. (donor) The F- cell is the recipient.

Conjugation F+ cell synthesizes a sex pillus. Sex pillus makes specific contact with the F- cell; pulling it toward the F+ cell.

Conjugation The DNA (plasmid) is transferred from the F+ to the F- cell through the sex pillus. Depending on the species, sometimes the plasmid is replicated first in the F+ cell and then transmitted to F-. Other times, the 2 DNA strands are separated in F+ and one strand is transferred to F-. Both cells will then make a complimentary strand..

The original F- cell turns into an F+ cell and can conjugate with other bacteria. Conjugative plasmids can spread rapidly through populations much like infectious agents. If plasmids contain genes that offer a selective advantage (like an antibiotic resistance gene), this can ensure survival of that population.

Think-Pair-Share Work with a partner and explain transformation, transduction, and conjugation to your partner. Exchange places and have your partner explain the same to you.

Create 6 groups We will create pantomimes of horizontal gene transfer. 2 groups – Transformation 2 groups- Transduction 2 groups - Conjugation

Lesson 9 Products of microbial biotechnology For homework read and familiarize yourself with the Powerpoint. Read each article on the website at the bottom of each slide and make a copy of it for your notes. Class Review: You will be assigned one of the articles and you will have to write an abstract of the article on the following day in class. Genetically modified foods Work with a partner and read research articles on genetically modified foods. Discuss the pros and cons of the argument with partner. Work in groups of 4 on assigned topic. Research on computer additional information to support your topic. Develop a 5 minute argument defending your position. Debate: One person from each group will present pro or con argument. Instead of rebuttal, each student will have to speak for 1 minutes about their opinion on genetically modified food. Class will vote at end of debate.

Lesson 9 Products of microbial biotechnology For homework read and familiarize yourself with the Powerpoint. Read each article on the website at the bottom of each slide and make a copy of it for your notes. Homework: You will be assigned one of the articles and you will have to write an abstract of the article on the following day in class. Genetically modified foods Work with a partner and read research articles (on handout) on genetically modified foods. Discuss the pros and cons of the argument with partner. Work in groups of 4 on assigned topic. Research on computer additional information to support your topic. Develop a 5 minute argument defending your position. Debate: One person from each group will present pro or con argument. Instead of rebuttal, each student will have to speak for 1 minutes about their opinion on genetically modified food. Class will vote at end of debate.

Products Microbial Biotechnology
Food Biotechnology - fermentation We have discussed fermentation of foods. Scientists are currently working on ways to improve micro-organisms for food production. - Developing virus resistant organisms through recombinant DNA technology to prevent economic losses in the dairy industry. - Developing bacteria to produce chemicals to kill contaminating organisms in food making processes. - Produced a microbial enzyme used to make cheese.

Enzymes, Antibiotics, and Human Proteins. Recombinant DNA technology has enabled production of new enzymes, antibiotics, and human proteins from microbial fermentation. Prourokinase is an enzyme which helps heal wounds infected with E.coli. New and novel antibiotics with two pathways for treatment are being developed. Tissue plasminogen activator, a protein which dissolves blood clots is being produced. Read about biotechnology and detergents.

Fuels and Biopolymers Hydrogen power is a fuel of the future. Biotechnologists are looking at Clostridium species as generators of hydrogen. Plastics worldwide are polluters because they are not biodegradable. Several organisms are being studied as producers of bioplastics. These biodegradable plastics will have several applications in the industrial and medical fields.

Agriculture A Pseudomonas bacteria has been bioengineered with B. thuringiensis toxin . The bacteria colonizes plants and acts as a biopesticide to kill insect larvae. Baculoviruses are used to contaminate plant material. Insects ingest the plant and develop a lethal viral infection Biotechnologists are working on ways to bioengineer the Baculovirus to enhance its ability as a biopesticide.

Products Microbial Technology
Bioremediation Microorganisms with hydrocarbon oxidizing enzymes clean oil spills. Microorganisms are used in waste water treatment facilities to purify water. Bacteria are being studied which have the capacity to remove heavy metals such as arsenic, copper, tin, and mercury from the environment.

Lesson 10 Lecture and discussion: Eukaryotic microbes and biotechnology products.

Lesson 10 Eukaryotic Cells
Eukaryotic cell review: Review structure & function, sketch a eukaryotic cell, and trace the pathway of lipoprotein assembly. Lecture: Yeast, Fungi, and Biotechnology products. Video: The Biology of Fungi (16 min) Reading and response: Evolutionary ties of fungi.

Microbial Eukaryotic Cells
Review of basic eukaryotic cell

Fungi – General Characteristics Fungi are composed of eukaryotic cells. Some are unicellular and some are multicellular. Habitats: Most are terrestrial and some are aquatic Energy : Fungi are heterotrophic decomposers. (A few are parasitic) Cell Walls: Resemble plants architecturally but are made of chitin not cellulose. Reproduction: Many reproduce asexually and sexually using spores. Recent molecular evidence suggests fungi are probably more closely related to animals than to plants or protists.

There are 3 basic types of fungi Unicellular fungi - Yeast Filamentous fungi – Mold and fungi Macroscopic fungi – Mushrooms We will limit our discussion to the first two types.

Yeast There are 1,500 species of yeast and yeast are not part of a single taxon. Cells - typically spherical, oval, or cylindrical - usually 3-4 microns in size - most are unicellular - some multicellular: a string of connected yeast cells connected by psuedohyphae.

Yeast with pseudohyphae Pseudohyphae help yeast invade tissues.

Yeast colonies growing on agar.

Energy Yeast flourish in environments where sugar is present. They are facultative aerobes; using aerobic cell respiration and fermentation. In a lab, yeast can be cultured with nutrient agar and grow colonies.

Reproduction Yeasts generally reproduce asexually by budding.

Reproduction Yeast can sexually reproduce by mating. Two different mating types fuse into a diploid cell. Diploid cell can bud to make additional diploid cells. Diploid cell undergoes meiosis and produces haploid cells called ascospores. Ascospores create new yeast cells.

Yeast containing ascospores.

Review What are the general characteristics of fungi?
Name the 3 types of fungi and provide an example. Describe the following: 1. Structure of yeast 2. Energy use in yeast 3. Asexual and sexual reproduction of yeast

Filamentous Fungi Widespread in nature, usually seen on stale bread, cheese, or fruit. Called molds.

Cell Structure A filament called a hypha (hyphae p,) grows from a single terminal cell  The hyphae grow together across a surface and form compact tufts called mycelium. This compact mat represents many intertwined hyphae. 

Cell Structure From the mycelium, hyphae grow upward. At the end of the vertical hyphae are spores called conidia. Conidia are asexual spores and are often pigmented.

Reproduction (asexual) The function of the conidia is the dispersal of the fungus(via spores) to new habitats. When new conidia form they are white and eventually become pigmented.

Reproduction (Sexual) Fungi can reproduce sexually. An example is bread mold Rhizopus. Hyphae called stolons of opposite mating types (+ & -) fuse to form a structure called gametangia Dipoid zygospore is formed. Zygospore produces sporandia which undergo meiosis and release haploid spores.

Review Describe the structure of a mold and the functions of each structure. Include the terms fungal cell, hyphae, mycelium, and conidia in your description. Explain fungal asexual and sexual reproduction.

Biology of Fungi http://www.youtube.com/watch?v=4NO299do_l4

Products Several yeasts, in particular Saccharomyces cerevisiae, have been widely used in biotechnology. S. cerevisiae is a simple eukaryotic cell, serving as a model organism for all eukaryotes. Fundamental cellular processes such as the cell cycle,, DNA replication, recombination, cell division, and metabolism have been studied. In 1996, S. cerevisiae was announced to be the first eukaryote to have its genome, consisting of 12 million base pairs, fully sequenced as part of the Genome project.

Products S. cerevisiae as a model organism has improved our understanding of human disease genes. Genetically engineered yeast and filamentous fungi have been used in the development of flavors, fragrances, food colorants, enzymes, pharmaceuticals (many human proteins), and solvents.

Lesson 11 MINI -Laboratory :Fungi
Read instructions for making a tease prep. Sketch a diagram of fungal structures and label. Please refer to your handout.

Lesson 12 Homework: Review and understand powerpoint and videos on virus structure, replication, and vectors. Class: Create 4 work groups and develop review questions on assigned slides Class: Present your slides and review questions to the class. Work in groups of 4 to create a rap song involving virus content. Create and present a rap song about viruses.(See handout).

Viruses General Properties
A minute particle containing nucleic acid, a protein coat, and sometimes other macromolecules. Can exist in extracellular or intracellular form. Extracellular –is metabolically inert. Intracellular – viral replication occurs,

Viruses - Genomes Genomes
Viral genomes are very small (3 to 100 genes)and encode for those functions that they cannot adapt from their host. Viral genomes are categorized by the type of nucleic acid present. Double stranded DNA Single stranded DNA Double stranded RNA Single stranded RNA Single stranded RNA that replicates with a DNA intermediate. Viral genomes can be linear or circular.

Viruses - Structure Virus Structure
Structures of viruses vary widely in size, shape, and chemical composition. Commonalities of structure Nucleic acid (DNA or RNA) Capsid- made of one to several proteins which surrounds nucleic acid. Envelope –most animal viruses have an envelope. The envelope is composed of a phopholipid bilayer from the host and proteins which the virus makes. Viruses without an envelope are called naked viruses.

Viruses - Structure Enzymes Some viruses contain enzymes.
Bacteriophages have lysozyme to make a small hole in bacterial cell wall. Retroviruses have reverse transcriptase that transcribes DNA from their RNA. Viruses have enzymes because the cell would not be able to replicate the viruses with out them.

Viruses - Replication Viral Replication
The phases of the replication process are Attachment Penetration Synthesis of nucleic acid and proteins Assembly Release

Viruses - Replication Attachment
Viruses are specific for the host cells they infect. Proteins on the outside of naked or enveloped virus interact with specific cell membrane receptors. If a cell membrane is altered, the virus cannot infect the cell; host resistance. However, viruses protein mutation enable viruses to interact with changed receptors.

Viruses - Replication Penetration
Three ways a virus can penetrate a cell membrane: Membrane Fusion or Hemifusion State: The cell membrane is punctured and made to further connect with the unfolding viral envelope. Entry Pore formation: An opening is established through which viral particles can then enter. Viral Penetration: The viral capsid or genome is injected into the host cell's cytoplasm. (enveloped viruses can uncoat the envelope at the cell membrane, cytoplasm, or nuclear membrane, depending on virus species).

Viruses Viral Attachment and penetration

Viruses - Replication Synthesis of nucleic acids and proteins - DNA viruses How viruses synthesize nucleic acids in the cell depends on the type of nucleic acid present in the virus. Double stranded DNA virus- Incorporates its DNA into the host genome and protein synthesis can begin. Single stranded DNA virus – A complimentary DNA strand must be synthesized in the host because RNA polymerase requires double stranded DNA.

Viruses - Replication Synthesis of nucleic acid and protein – RNA viruses RNA viruses need an RNA-dependent RNA-polymerase to replicate their RNA. Cells do not have this enzyme. RNA viruses need to code for an RNA-dependent RNA polymerase. No viral proteins can be made until viral messenger RNA is available . The nature of the RNA in the virus affects its replication strategy.

Viruses - Replication Synthesis of nucleic acids and proteins- RNA virus Single stranded RNA virus – There are 2 types of single stranded RNA viruses. Plus-stranded RNA viruses -In these viruses,RNA is the same sense (direction) as mRNA and it functions as mRNA. This mRNA can be translated immediately upon infection of the host cell. Negative-stranded RNA viruses - The virus RNA is negative sense (complementary to mRNA) and must therefore be copied into the complementary plus-sense mRNA before proteins can be made. The virus uses its own RNA polymerase to make the plus stranded m RNA. Double-stranded RNA virus - The virus RNA is double stranded and can’t function as mRNA; these viruses also need to package an RNA polymerase to make their mRNA after infection of the host cell.

Viruses - Replication Synthesis of nucleic acids and proteins – retrovirus. The single strand of retrovirus RNA serves as a template to make a single strand of DNA with the virus’ enzyme reverse transcriptase. A complimentary DNA strand is made and the double stranded DNA is then a template for mRNA synthesis.

Viruses – Replication Synthesis of nucleic acids and proteins
Once mRNA is made proteins can by synthesized. Early proteins – are made first which are necessary for viral replication. Late proteins- are then synthesized such as the viral coat protein.

Viruses - Replication Assembly Viruses self assemble in cells.
Virus self-assembly within host cells has implications for the study of the origin of life, as it lends credence to the hypothesis that life could have started as self-assembling organic molecule

Viruses Release Naked virus release
Enveloped virus release

Viruses - Vector Viruses as vectors
Vector (in biotechnology) DNA that can be used to carry and replicate foreign DNA in biotechnology experiments. Viruses can serve as vectors. Genes of interest can be inserted into the viral genome and the genes of interest will replicate along with the virus.

Viruses - Vector Viral vectors can be delivery system for gene therapy. Viruses have potential as delivery systems in gene therapy because A. They naturally enter cells. B. They can integrate in the host cell genome. C. They are cell specific which would allow for targeted gene therapy.

Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions.

Similar presentations

Presentation on theme: "Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions."— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions.

Similar presentations

Presentation on theme: "Lesson 4 View the video “Microbial Evolution” and respond to student worksheet Lecture: Species Concept and Evolutionary Domains. Response to questions."— Presentation transcript:

Similar presentations

About project

Feedback