Deoxyribose Lab

In the test for a reducing sugar, if it changes to a red orange color is it known as a precipitate as it comes out of the solution and forms solid particles dispersed around the water. The test of non-reducing sugar is striving as a result of if there is any sucrose presents it is broken down into those monosaccharides, which can be proved for using the common reducing sugar test. A positive result indicates that non-reducing sugars are present on the original sample. Sucrose fermentation it involves inoculating of sucrose broth with inoculating loop. Usually done for the differentiation of Enterobacteriaceae species.

Once iodine was dropped onto the circle, which was labeled “HCL+ saliva”, was divided into two colours, white and navy blue, this arose because the starch did not get broken down. The enzyme got denatured with the extension of hydrochloric acid of hydrochloric acid. The acid found in hydrochloric acid obtains a low level oh pH (2), causing it not to be broken down, rather to be denatured, confirms amylase can’t continue it’s activity without a particular high amount of acid, (that is found in stomach acid). My hypothesis is incorrect due to the fact that my prediction is

Discussion: End point in this acid-base titration experiment refers to the point where the chemical reaction has reached its conclusion and no additional titrant should be added. The end point of this experiment can be obtained when the indicator used changes colour. For example colourless to light pink when phenolphthalein is used and red to orange and subsequently yellow when methyl orange is used. Equivalence point, also known as stoichiometric point in an acid-base titration refers to the point where the reacting acid and base is in equal proportions. In the graph plotted, pH against volume of NaOH, the graph becomes nearly vertical at the equivalence point.

Biuret test is a test which is utilized to indicate unhydrolyzed proteins. When there are peptides in a solution, a copper (II) ion forms violet-coloured coordination complexes in an alkaline solution. The biuret test can be utilised to analyse the concentration of proteins due to peptide bonds that occur with the same frequency per amino acid inside the peptide. In this experiment, the colour changed to purple to indicate the presence of protein. The pH was found to be 7, which is in the range of a healthy person’s pH (which is 7.4).Benedict`s solution is made up of alkaline copper sulphate and sodium citrate (blue in colour) (Danson and et al, 1996).

Therefore, acid fat, lactose fermentation, mannitol fermentation were not needed to be performed, because they are selective to a specific thing. As a result, Unknown bacteria “W” was concluded to be gram stain positive, endospore positive, bacilli shape (rod shape), and arranged in chains (strepto-). Test Purpose Reagents Observation Results Gram Stain To determine gram reaction of bacteria.

1. How pure is your sample? When analysing our sample under UV light we could see if our sample was pure. We labelled the sample with 1= which was our sample, 2= the pure aspirin sample, 3= the salicylic acid.

Enzymes are proteins that lower the activation energy needed for a chemical reaction in the body. The chemicals that they act on are called substrates. When combined with their substrates, the enzymes decrease the amount of energy needed for a chemical reaction to occur. Enzymes are similar to a lock and key, because one enzyme can only work on a specific substrate, just like only one key can fit into a lock. Each enzyme has an ideal environment, and if the environment of an enzyme changes, the enzyme’s ability could decrease.

CHAPTER 3 EXPERIMENTAL PROCEDURE 3.1 Materials & Reagents Adsorption of Cu (II) was studied using Montmorillonite-K 10, procured from Sigma Aldrich. It is a very soft phyllosilicate group of minerals that typically form in microscopic crystals, forming clay. Its Cation Exchange Capacity, CEC was 119 meq/100 g .The elemental composition of this clay was [Al1.47Fe0.29Mg0.23][Al0.076Si3.29]O10(OH)2 as reported by the supplier.

This test tube lacked hydrogen peroxide in order to keep the reaction from occuring. In two test tubes labeled “Substrate”, we mixed 0.2 ml of hydrogen peroxide with 0.1 ml guaiacol and 4.7 ml of distilled water. We also labeled two test tubes “enzyme” using a glass marking pen and filled them with 1.0 ml of turnip extract and 4.0 ml of distilled water. After the test tubes were prepared, we put the blank test tube into a cuvette and put it into the spectrophotometer in order to zero it out. While one group member set the spectrophotometer to zero, another mixed one enzyme test tube with one substrate tube and observed a change in it’s color.

Blank solution and oil solution were prepared and stored in the dark. Then, they were titrated with Na2S2O3 and volume of titrant was determined for blank and oil solution. Finally, iodine value was determined by using volumeaof titrant. B) Determination of Peroxide Value In this experiment, peroxide value of sunflower oil was tried to determine.

The Ornitine Decarboxylase (ODC) results were yellow so it, too, was negative. My Citrate (CIT) result was turquoise so that meant the test was positive, and the Hydrogen Sulfide (H2S) had no black precipitate so it was negative. The Urea (URE) and Tryptophane Deaminase (TDA) results were both an orange color, which meant they were both negative. For Indole (IND), my result was yellow

More specifically, this lab was met in terms of gaining an understanding in separating an acid, base and neutral compound from a mixture and identify through melting point. Overall, the experiment was successful as the acid (benzoic), base (5-chloro-2- methoxyaniline) and neutral (biphenyl) compounds were correctly identified. The separation of mixtures compounds to give pure components is of great importance in chemistry and in specific in organic chemistry. Many synthetic reactions give mixtures of products and it is important to isolate the wanted compound with a precise methodology of extraction and purification. Identification of the compound can always be identified by melting point

This lab’s end result was to correctly identify each unknown solution using prior knowledge of chemical properties and the results of the first experiment conducted. Unknown solution D was the only colored solution, being blue while the others were clear. This made it easy to then match D up to Copper Sulfate because of its color. As unknown A and B were added together, lots of gaseous bubbles formed and revealed the fact that that reaction was the reaction between Hydrochloric Acid and Sodium Carbonate because it was the only reaction that produced a gas release. Unknown A and C produced the only yellow, brown precipitate just as the reaction between Sodium Carbonate and Silver Nitrate had previously.

When determining the solubility of malonic acid in different solvents both water and methyl alcohol were found to be polar when mixed with malonic acid. Hexane however was insoluble. Lastly biphenyl was mixed with water and was found to be insoluble, methyl alcohol was determined to be partially soluble. Hexane on the other hand was the only soluble solvent for biphenyl 2. Part B. of this experiment determined the solubility of different alcohols in hexane or water.

The phenol-red indicator helps to identify the bacteria. Upon viewing my results it was determined that my colonies did not ferment mannitol. This was easily observed because they remained translucent. The incubation times for all of the inoculated tests were for 48 hours (due to lab schedule, supposed to be 24 hours) and the temperature they were incubated at was at 37C. 37C is the optimal temperature to maintain the state of the agar as well as the ideal temperature for continued microbial growth to occur. My fourth and final test conducted to help identify my bacteria was an Oxidase test.