The role of oxysterols in human body and disease
Oxysterols are 27-carbon derivatives of cholesterol created by spontaneous or enzymatic oxidation (Figure 1, (Brown and Jessup, 2009)). The oxidation of cholesterol occurs either on the side chain or on the sterol core. Side chain oxidation generates, e.g., 24-hydroxycholesterol (24-HC), 25-hydroxycholesterol (25-HC) or 27-hydroxycholesterol (27-HC) while the core oxidation gives rise to ring oxysterols, mostly ring-B oxysterols,…
In pursuit of our continued interest in the development of solvent-free and green synthetic procedures, we decided to explore the use of tartaric acid catalyst for synthesis of polysubstituted quinolines via Friedlander condensation in high to excellent yields at 70 °C under solvent-free conditions. Initially the reaction between 2-aminobenzophenone (1.0 mmol) and dimedone (1.0 mmol), as the model reaction was examined in the presence varying amount of tartaric acid as catalyst and the results…
Sterile Saline (0.9% w/v NaCl)
Dissolve 9.0gm of NaCl in 1000ml water and dispense 9.0ml of the solution into 20ml test tubes. Autoclave the tubes as per the validated cycle and cool to room temperature.
Sterile saline with polysorbate 80:
Dissolve 9.0gm of NaCl in 1000ml water and add .5gm of tween 80 to the resulting saline solution, dispense 9.0 ml of the solution into a number of 20ml test tubes. Autoclave the tubes
Preparation of Inoculums and its Standardization:
1) Take loop full of…
The purpose and objective of this experiment was to determine the percent by mass of acetic acid within a sample of vinegar using volumetric analysis with the titration technique. The theory is that if the volume and molar concentration of the standardized sodium hydroxide (NaOH) solution is known, then the percent by mass of the acetic acid (CH3COOH) in vinegar can be calculated after a titration.1 Within this experiment, a NaOH solution was standardized with a primary standard acid of…
TRIS Hcl, NBT, NADH, Ethanol, PMS, l-ascorbic acid
1. The superoxide radicals is generated in 3 ml of TrisHCl buffer (16 mM, pH 8.0) containing 1 ml of NBT (50 μM), 1 ml NADH (78 μM) and ethanol extract of sample (25 – 50 μg).
2. The reaction was started by adding 1 ml of PMS solution (10 μM) to the mixture.
3. The reaction mixture was incubated at 25° C for 5 min, the absorbance was read at 560 nm using a spectrophotometer (Schimadzu UV-Vis 1700) against blank samples using l- ascorbic acid…
AP Biology, A2
15 September, 2015
Measure the activity of catalase in potato extract using several different methods.
a) Cut 20 small circles from a large filter paper disk using a hole puncher. Clean and dry several medicine cups and pour hydrogen peroxide into one. Put the catalase enzyme, previously prepared by blending a potato, into another medicine cup. Make a 1/8 dilution of the catalase by adding chilled distilled water.…
the plate.5 Thus, compounds are separated according to their differing behavior in the adsorbent-solvent system, with their final heights on the plate and Rf values determined, in general, by their relative degrees of polarity. For best results, acetic acid was a necessary component of the development solvent in this experiment because it was a source of protons, which prevented the…
The effects of caffeine on Daphnia magna
Lab Section: P0501
1. Materials and Methods:
Clean 3-well specimen chambers were kept in ice and a cooling chamber was then prepared to be put under the microscope, by filling it with ice and a small volume of water. This was done to ensure the temperature would remain around 15 degrees Celcius, which could keep Daphnia magna efficiently cool. Furthermore, the different concentrations were prepared in separately…
experiment tested why mixing reactants in different mole ratios affected the amount of the product and the amount of each reactant that is left over.
To solve the problem, the lab contained reacting sodium bicarbonate(baking soda) and acetic acid(vinegar) in different ratios and seeing if the product changed. The data suggests that the higher ratio of baking soda to vinegar creates the most product. For the ratio 3:1, the final grams of sodium acetate(product) was 0.09, the product…
This lab used techniques in steam distillation to extract crude oil from cloves. The cloves were boiled in a round bottom flask and using a hydrodistillation apparatus, the crude oil was separated from the cloves and sent into a clean flask. This step was used to separate the essential oils from the cloves (Setzer, W., 2008).
The distillate was poured into a separatory funnel and extracted three times with dichloromethane to extract the water. After being extracted three times, a fifth of the…