Bacterial growth may be controlled by many methods; the techniques relevant to this experiment include heat, ultraviolet (UV) light, and antimicrobial control. Using heat as a means of controlling bacterial growth is favorable because it is quick, safe, and cost-effective (Nester, 2007). There are two kinds of heat: moist heat, which destroys the proteins of microorganisms by boiling or steaming, and dry heat, which requires high temperatures to oxidize cell components and damage proteins by incineration or dry heat ovens (Nester, 2007). Cellular proteins are essential in carrying out important biological activities, so without them, the bacteria will not be able to survive (Nester, 2007). Moist heat is widely used to treat drinking water, …show more content…
pasteurize milk, sterilize microbiological media, or in the commercial canning industry (Nester, 2007). Dry heat is often used to flame inoculation loops and destroy medical waste (Nester 2007). UV light is a form of radiation that damages the DNA of cells; however, it penetrates poorly, so it is most effective when it is used in close-range and directly exposed to the microorganism (Nester, 2007). DNA is crucial for the proper functioning of cells, as it contains all the information necessary to carry out the biological functioning of the cell; thus, if this mechanism is hindered, the cell may not survive (Murnaghan, 2015). UV light is often used to disinfect surfaces and treat drinking water. Antimicrobials, including antibiotics, antiseptics, and disinfectants, kill or inhibit the growth of microorganisms by targeting specific areas of the microorganism (Nester, 2007). For example, the antibiotic tetracycline blocks the attachment of tRNA to the prokaryotic bacterial ribosome, which is different from a eukaryotic ribosome, and thus effective for bacteria and not harmful to humans (Nester, 2007). Antibiotics and antiseptics are both substances that prevent the growth of microorganisms, but they differ in the specific kinds of organisms they target (Nester, 2007). Antibiotics kill or inhibit the growth of bacteria, specifically; they do not have an effect on other microorganisms, such as viruses or fungi (Nester, 2007). Antiseptics and disinfectants target a wider variety of microorganisms and have more of an inhibitory effect. In this experiment, the Kirby-Bauer test was used to determine the susceptibility of bacteria to an antibiotic.
The Kirby-Bauer test was developed in the 1950s by W. Kirby and A. Bauer and their co-workers as a form of susceptibility testing; in 1961, the test was standardized by the World Health Organization (Reynolds, 2001). The purpose of the Kirby-Bauer test is to determine whether bacteria are susceptible, intermediate, or resistant to a specific antibiotic (Hudzicki, 2013). A filter paper is soaked with the antibiotic and placed on an agar plate; after it is incubated, the diameter of the zone of inhibition (area of no bacterial growth around the filter paper) is measured and compared to a standard zone chart to determine the susceptibility of the bacteria to the specific antibiotic (Hudzicki, …show more content…
2013). The antibiotics used in this lab experiment include streptomycin, penicillin, erythromycin, chloramphenicol, tetracycline, and lincomycin.
Streptomycin is part of the category of aminoglycosides (Nester, 2007). Aminoglycosides and tetracyclines affect the ribosomes of bacterial cells; aminoglycosides block the initiation phase of translation during protein synthesis, which causes a misreading of mRNA, and tetracycline blocks the attachment of tRNA to the ribosome of the bacterial cell (Nester, 2007). Aminoglycosides also have a low therapeutic index, meaning it can be harmful to humans (Nester, 2007). Streptomycin is often used for treating tuberculosis and tetracycline is used for a variety of bacterial infections, including Lyme disease and syphilis (Nester, 2007). Penicillin includes a family of antimicrobial medications that interfere with the cell wall synthesis of bacteria; penicillin often treats pneumonia and UTIs, for instance (Nester, 2007). Erythromycin prevents the continuation of protein synthesis, and is often the drug of choice for people that are allergic to penicillin, and thus has similar uses (Nester, 2007). Chloramphenicol is a broad-spectrum antibiotic that prevents peptide bonds from being formed in bacterial cells; it has a low therapeutic index, however, so it is used a last-resort drug (Nester, 2007). Lincomycin has the same mechanism of bacterial growth control as chloramphenicol and is often used to treat severe bacterial infections. There were
also various antiseptics and disinfectants used in this experiment including Lysol, Clorox, and bleach, which are common household disinfectants used to clean surfaces and clothes, ethanol (alcohol), mouthwash, glycerol (used to form soap), and betadine (used on eyes and sk
One bacterium was gram negative. It underwent four different tests. These tests were the EMB test (Eosin Mehylene Blue), the Sulfur Indole Motility (SIM) test, the Urease test, and the Simmon’s Citrate Utilization test. The EMB test checks for a bacteria’s ability to ferment lactose. This test is accomplished by placing the bacteria on Eosin Methylene Blue agar. The agar is selective for gram negative bacteria and those bacteria that can ferment lactose will have colored growth, usually a metallic green sheen.
After the end of the experiment, the unknown 10 sample was Staphylococcus epidermidis. Come to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man-made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester, it was determined that the blood agar, MSA, and catalase tests are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria.
In the experiment “ Talking to plants “ from Mythbusters, potential problems include the use of greenhouses with no sound insulation, a non-homogeneous location and the use of only one specie to infer on a population. In another scientific study, researchers chose to use “ a noiseless growth chamber to prevent any effects from extraneous noise “ and the use “ growth chambers under continuous light at 28 c and 65-75% relative humidity “ in order to maintain a homogeneous location for all plants during the experiment (Jeong et al., 2008) . This helped further explain the findings because with the use of noiseless chambers you can assure that the only noise that the plant was receiving was the one given in the treatment and a valid conclusion
In this experiment the heat shock method will be used to deliver a vector (plasmid) of GFP to transform and grow E. coli bacteria. Four plates containing Luria Bertani (LB) broth and either –pGLO and +pGLO will have E. coli bacteria added to it. The plate containing –pGLO (no pGLO) and LB will show growth as ampicillin will be present killing bacteria but no glowing because no arabinose will be present for glowing to be activated, the same result will be seen in the plate containing +pGLO, LB and ampicillin. The plate with –pGLO, LB and ampicillin will show no growth and no glowing as no arabinose is present for glowing to be activated
In the last decade, the number of prescriptions for antibiotics has increases. Even though, antibiotics are helpful, an excess amount of antibiotics can be dangerous. Quite often antibiotics are wrongly prescribed to cure viruses when they are meant to target bacteria. Antibiotics are a type of medicine that is prone to kill microorganisms, or bacteria. By examining the PBS documentary Hunting the Nightmare Bacteria and the article “U.S. government taps GlaxoSmithKline for New Antibiotics” by Ben Hirschler as well as a few other articles can help depict the problem that is of doctors prescribing antibiotics wrongly or excessively, which can led to becoming harmful to the body.
Summary Dr. Stanley Milgram conducted a study at Yale University in 1962, in an attempt to understand how individuals will obey directions or commands. This study became known as the Milgram Obedience Study. Stanley Milgram wanted to understand how normal people could become inhumane, cruel, and severely hurt other people when told to carry out an order, in blind obedience to authority. This curiosity stemmed from the Nazi soldiers in Germany, and how their soldiers could do horrible acts to the Jews. To carry out his study, Dr. Milgram created a machine with an ascending row of switches that were marked with an increasing level of voltage that could be inflicted on another person.
Ever since the discovery of antibiotics in the 1920’s, treating bacterial infections in humans, and animals alike, has emerged as a revolutionary possibility. Antibiotics are drugs that are naturally produced by bacteria or fungus to defend against other bacteria via death or inhibiting reproduction (1). Since their detection, antibiotics have been diversified into many different forms and classes which are arranged by mode of action. Glycopeptides are a class of antibiotics which are composed of glycolsylated cyclic or polycyclic nonribosomal peptides that inhibit cell wall synthesis in susceptible bacteria (2). However, it was soon discovered that the use of these antibiotic drugs would lead to antibiotic resistance. This paper will discuss the history, function, and resistance associated with vancomycin, a glycopeptide antibiotic.
The Little Albert experiment has become a widely known case study that is continuously discussed by a large number of psychology professionals. In 1920, behaviorist John Watson and his assistant Rosalie Rayner began to conduct one of the first experiments done with a child. Stability played a major factor in choosing Albert for this case study, as Watson wanted to ensure that they would do as little harm as possible during the experiment. Watson’s method of choice for this experiment was to use principles of classic conditioning to create a stimulus in children that would result in fear. Since Watson wanted to condition Albert, a variety of objects were used that would otherwise not scare him. These objects included a white rat, blocks, a rabbit, a dog, a fur coat, wool, and a Santa Claus mask. Albert’s conditioning began with a series of emotional tests that became part of a routine in which Watson and Rayner were determining whether other stimuli’s could cause fear.
The experiment I’ll be exploring is the Harry Harlow experiment. Harlow theme of his experiment targeted the ideal of attachment between animal; human and monkeys. The need for and the different types of attachments. Harlow focused on how it affected the brain both negatively and positively based on one’s individual variables and differences. Harlow conducted experiments on baby monkeys to see how their behavior would develop if they didn’t have the influence of a mother monkey. Harlow placed infant monkeys into different crates which held a wire-mother, and a cloth mother. These objects represented the touch of an actual mother monkey. While observing the monkeys behavior Harlow noticed that there were things similar to children such as social withdrawal. Harlow did many tests and in one discovered that the hormone levels in some of the isolated monkeys were much higher than those of the non-separated monkeys. In Correspondence some of the growth hormone levels were less in many of the isolated monkeys and higher in the normal ones.
We all have our own perception of psychiatric hospitals. Some people may see them as a terrifying experience, and others may see them as a way to help people who cannot keep their disorders under control. David Rosenhan's perception led him to a variety of questions. How could psychiatric hospitals know if a patient was insane or not? What is like to be a patient there? According to Rosenhans study, psychiatric hospitals have no way of truly knowing what patients are insane or not; they quickly jump to labeling and depersonalizing their patients instead of spending time with them to observe their personality.
This paper will give an introduction and a brief overview in the different stabilities and pharmacokinetics of the erythromycin salts and an introduction into new approaches in the field of macrolide antibiotics.
Cooley performed extensive testing on children in an environment that was controlled. In this controlled setting children were told to go into a room and only take one piece of candy. While the children were there alone, they were being monitored by using a video camera. While in the room, the children took more candy than they were supposed to. The test was repeated, but instead of a regular room the children were in a room full of mirrors (Charles Horton Cooley, n.d.). In this specific experiment, most of the children only took one piece of candy. Cooley interpreted these results and saw that if children were able to see their own behavior, they would change because of guilt. He went on the suggest that they only picked one piece because
This essay takes a look at how the given passage from Christopher Marlowe’s Doctor Faustus reflects the play as a whole, and what the passage contributes to the play. Doctor Faustus deals with many issues, for instance: the failure of ‘Renaissance man—of his dreams and aspirations and, more particularly, his failures and illusions.’ This idea of overreaching is central to the excerpt. Moreover, religion plays a large role in the extract, and continues to resonate throughout the entire play. This paper looks at both, the overreaching Renaissance man and religion, closely to show the importance of the passage under analysis to the complete work. Moreover, during Marlowe’s time, drama was considered to be ‘a satanic opposition to the Word of God’; therefore, this essay will determine whether Doctor Faustus was originally created to challenge or subvert such criticism. Furthermore, the poetic style, rhetorical devices, and intertextuality Marlowe employs are analysed to show how they may be different to the rest of the play, and how this affects the play as a whole. It is important to recognise that Marlowe’s personal life and beliefs may have had an impact on his work; however, this paper focuses on the play itself, and does not draw parallels with Marlowe and, the protagonist, Faustus. All in all, this essay considers whether one can see the entirety of the play in the chosen section.
In 1963 Stanley Milgram, a social psychologist developed an experiment that raised awareness on how human beings are capable to act cruel towards others when following commands from someone with high authority. Obedience to authority can cause people to behave different form their own personal beliefs, causing someone to do evil things. For instance, Adolf Eichmann organized the holocaust in Germany that lead to death of six millions people. He ordered his soldiers to collect and exterminate victims that were killed during the Nazi Germany government (McLeod, 2007). After WWII, people became aware of the evil acts committed by the Nazis under Hitler’s authority, while Nazis reported to harming and killing people because they were following
The aim of this investigation is to: 1) find the rate equation for the reaction between hydrogen peroxide, potassium iodide and sulphuric acid by using the iodine stop clock method and plotting graphs of 1/time against concentration for each variable. Then to find the activation energy by carrying out the experiment at different temperatures using constant amounts of each reactant and then by plotting a graph of in 1/t against I/T, 3) to deduce as much information about the mechanism as possible from the rate equation.