Essay On Reductive Dehalogenation

The organism fermented the sugar producing an acid which caused the phenol red pH indicator in the broth to become yellow. Phenol red is red in basic conditions and yellow in acidic conditions. Under oxygen limiting conditions, some organisms utilize sulfur compounds as terminal election acceptors (lab manual). The byproduct of this reaction is hydrogen sulfide. The medium contains iron salt which binds with hydrogen sulfide to produce a black color.

  Sucrose fermentation: This fermentation makes energy available for use by microorganisms by anaerobic breakdown of carbohydrates. It can either be an acid or gas. When positive turns red to yellow and can have gas present which form bubbles.   H2S production: H2S is a toxic gas produced by the decomposition of sulfur-containing amino acids cysteine and methionine or the reduction of inorganic sulfur compounds by enzymes of certain bacteria. If hydrogen sulfide is formed, it reacts with ferrous salts to form black metal sulfides that can be visualized

The medium did not change color after the Kovac reagent was added. Thus, the microorganism was not able to reduce sulfur to hydrogen sulfide (Leboffe and Pierce 202). The lack of blackening in the medium confirms the negative results. The organism tested negative for indole production. If indole was produced, dimethylaminobenzaldehyde (DMABA), which is in the reagent, would reacts with any indole that is present in the media (Leboffe and Pierce 202,203).

Many organisms use energy to perform their cellular functions. That energy comes from the energy that is stored in food then converted to adenosine triphosphate or ATP. ATP can be obtained with or without oxygen, aerobic respiration and anaerobic respiration. Aerobic respiration produces carbon dioxide (CO2) as a by-product while anaerobic respiration produces Ethanol (C2H6O) or Lactic acid (C3H6O3). In aerobic respiration the “CO2 produced during cellular respiration can combine with water to produce carbonic acid.”

There are several reactions occur when there is plenty of oxygen present. Then the energy released is used by the yeast for growth and activity. However, when the oxygen supply is limited, the yeast can only partially breakdown the sugar. Alcohol and carbon dioxide are produced in this process known as alcoholic fermentation. The fermentation occur when the carbon dioxide produced in these reactions.

We got negative for indole (no production of indole, pyruvic acid and ammonia), negative for Methyl Red (our bacteria does not perform mixed-acid fermentation when supplied glucose), negative for Voges-Proskauer (no fermentation of glucose in order to produce 2,3-Butanediol-Butanediol fermentation), but positive for Citrate utilization, which means our bacteria uses citrate as a sole carbon source and energy. Something interesting here is that according to the lab textbook organism that degrade citrate must also use ammonium salts, and in the process, they produce ammonia that causes the medium to become alkaline (under this condition the medium turns to deep Prussian blue, indicating the utilization of citrate). The genus Alcaligenes is well known for being alkali-producing

For example, fermentation occurs in yeast in order to gain energy by transforming sugar into alcohol. Fermentation is also used by bacteria, they convert carbohydrates into lactic acid. Ethanol fermentation is done by yeast and certain bacteria, when pyruvate is separated into ethanol and carbon dioxide. Ethanol fermentation has a net chemical equation: C6H12O6 (glucose) > 2C2H5OH (ethanol) + 2CO2 (carbon dioxide). This process of ethanol fermentation is used in the making of wine, bread, and beer.

Introduction: Enzymes are biological catalysts that increase the rate of a reaction without being chemically changed. Enzymes are globular proteins that contain an active site. A specific substrate binds to the active site of the enzyme chemically and structurally (4). Enzymes also increase the rate of a reaction by decreasing the activation energy for that reaction which is the minimum energy required for the reaction to take place (3). Multiple factors affect the activity of an enzyme (1).

Introduction In class, a series of experiments were performed that pertained to the enzyme known as catalase, which converts hydrogen peroxide into oxygen. Due to peroxide being toxic to the tissues of both plants and animals, both possess the enzyme catalase, which breaks into two non-toxic compounds: water and oxygen gas. Enzymes are proteins that react to certain substrates to create a product, and continue doing so afterwards. Methods and Materials To test reactions between catalase and hydrogen peroxide, groups of three to four people were formed.

Distortion of reality is a symptom of mental illness and also known as derealization. In this disorder, a person feels that his surrounding is not real. Having a feeling of detachment from reality is normal. But it turns into a disorder when you repeatedly or persistently have the feelings that you are detached from your body or the things in your surroundings are not real.

Sugar/ glucose is an important carbohydrate that can be made during photosynthesis from water and carbon dioxide, using energy from sunlight. Carbon dioxide is given off as a waste product when energy is released by the breaking down of glucose. This can be used by plant cells in the process of photosynthesis to form new carbohydrates. Yeast is a single-celled fungus that can break down sugars (glucose) to help produce carbon dioxide. Research Question

As a result the presence of the enzyme catalase in the cell helps to quickly convert this toxic substrate into safer products of water and oxygen (All Science Fair Projects, 2004). Hypothesis: According to the Collision Theory, in order for a reaction to occur, particles need to collide with a sufficient amount of energy and with the correct orientation. The temperature of the particles can affect the rate at which the particles collide.

Chemistry Extended Essay “How does pH affect the concentration of trihalomethanes formed in a sample of reservoir water when it is disinfected with chlorine or chloramine and to what extent do both chloramine and free chlorine decompose when exposed to ultraviolet light?” Abstract This investigation aims to find out how pH affects the concentration of trihalomethanes formed in a sample of reservoir water when it is disinfected with chlorine or chloramine and the extent to which both free chlorine and chloramine decompose when exposed to ultraviolet light. Headspace gas chromatography and mass spectrometry were used to measure the concentration of the four main constituents of total trihalomethanes (TTHMs), namely chloroform,

Disinfection Chemicals Introduction Water disinfection is removal, deactivation or elimination of pathogenic bacteria. Bacteria gets damaged or even deactivated, disabling reproduction. Disinfectants must not just eliminate bacteria. They must have residual effect. The disinfectant must not allow pathogenic bacteria to develop within the domestic plumbing after disinfection, causing water being decontaminated.

They can also act as a final electron acceptor. Many bacteria can be differentiated and are identified by their capacity to reduce nitrates to nitrites. Most of the bacteria belonging to the family Enterobacteriaceae reduce nitrates [165]. OF test is used to differentiate those organisms that utilize carbohydrates aerobically (Oxidation) such as P. aeruginosa, from those that utilize carbohydrates anaerobically (Fermentation) such as members of the Enterobacteriaaceae. The OF medium contains peptone, test carbohydrate and bromothymol blue as indicator.