Refrigeration slows food spoilage because the lower temperature slows binary fission. Under optimal conditions with no limiting factors prokaryotes can grow exponentially. 3. Some bacteria can form endospores in response to harsh environmental conditions. An endospore is a chromosome surrounded by a durable wall that can resist desiccation, freezing and boiling water.
By using the genes from two bacteria producing organisms such as Alcaligenes Eutrophus, they could insert them into cress plants with the aim of these plants producing the PHB. This process worked and the plants and some of their offspring produced around 14% of the dry weight as PHB. Although this is not as high yielding as when it is produced in the petri dishes, it is a much more economically viable method of production and hence would give a much more substantial impact to society. Chemically PHB is from a group of biopolymers known as the polyhyroxyalkanoates. Figure 1 below shows other examples of biopolymers in
This protein causes the jellyfish to glow in the dark. With gene transformation the bacteria will acquire this trait and they wil glow underneath an ultraviolet light. Bacteria contain a large singular chromosome and one or more smaller circular pieces of DNA called plasmids. these plasmids usually contain one or more genes that are beneficial to the survival of the bacteria. in nature, the bacteria can transfer these plasmids from bacteria to bacteria, transfering those beneficial genes.
| | | A) | endoplastic reticulum | | | B) | microtubules | | | C) | cytoplasm | | | D) | mitochondria | | | | | | Feedback: The cell's chemical processes take place in a semifluid material called the cytoplasm. This material provides an ideal environment for organelles because of its fluidity. | | 7 CORRECT | | This shows an example of endoplasmic reticulum. What is the significance of its structure? | | | A) | provides a location for DNA production | | | B) | helps decrease surface area | | | C) | allows selective permeability of cell membrane | | | D) | facilitates breakdown of chemical bonds | | | | | | Feedback: The pleats and folds of the endoplasmic reticulum provides a large surface area where cellular functions, such as breaking chemical bonds, can take place.
3. Why is it necessary to make pure subcultures of organisms grown from clinical specimens? So that the organism can be identified and tested for antibiotic sensitivities. 4. What kinds of clinical specimens may yield a mixed flora in bacterial cultures?
c) Name 2 different methods of measuring pH of substances (in a laboratory)? • Probe and meter • Litmus paper 5. Explain the relationship between the natural pH of the skin and the action of: a) Microflora • The bacterial microflora on our skin are able to survive acidic conditions with a pH range 4-6. Our acidic skin protects us from harmful bacteria or pathogens, our microflora are able to breakdown the fatty acid molecules and thereby increase its
Report One: Physical and metabolic characterization of unknown soil organism The objective of labs 1, 2, 3 is to find the physical and metabolic characterization of the unknown soil organism that was collected on campus. I collected my sample from the soil in the flower garden located outside of the BME building. After collecting my soil sample, I swabbed the sample on a NA plate. The following picture is the growth of the unknown soil sample after swabbing it on the NA plate. As you can see from this picture, there are many large, flat white colonies with irregular borders that are scatterred on the NA plate.
1) Genetic engineering or genetic modification is the process of altering an organism’s genetic material for a beneficial purpose. Genetic modification is used to improve the products we obtain from plants and animals making them more nutritious, less-harmful manufacturing processes, and production in large quantities making them less expensive. 2) Gene Therapy- when an absent or faulty gene is replaced by a normal gene in order to treat a disorder or medical disease Plasmid- small circular DNA molecules in the cytoplasm of bacteria, these molecules cut DNA into a recognizable sequences DNA Polymerase Chain (PCR)- technique used to make copies of a certain gene. Biologists particularly use this with tiny genes that are rarely available. Hybridization- crossing different traits to bring the best of organisms into one.
In order to break this link, various methods can be used, including the pasteurization of milk, the chlorination of drinking water, or the use of disinfectants. 2. The Reservoir. This is the natural environment that the pathogen requires for survival. Reservoirs can be a person, an animal, or an environmental component, such as soil or water.
This pro-infection role of the microbiota has been demonstrated in many cases of enteric infection. For instance, poliovirus relies on the microbiota for efficient replication, mainly through binding to microbial products such as LPS. Similarly, the retrovirus mouse mammary tumor virus (MMTV) can bind to bacterial LPS, triggering TLR4 and subsequent induction of the inhibitory cytokine IL-10 and inducing an immune evasion pathway.143 In these studies, the elements accounting for efficient pathogen transmission are highly represented microbial products, which illustrates the fact that viruses and perhaps other pathogens have evolved to bypass commensal bacteria population shifts by thriving on ubiquitous microbial