Biology Spectrophotometer In Biology

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Enzymes are specialized proteins present in all living organisms, whether animals, plants or microorganisms (Reece et al., 2012) .In addition, life would cease to exist without these vital organic molecules, as they are needed for metabolic processes, and other reactions and processes in the body (Reece et al., 2012). Sometimes some RNA molecules can act as enzymes (Reece et al., 2012). Enzymes as well as their substrates work best at optimal levels, and are affected by temperature and pH environments (Reece et al., 2012). Other factors that influence enzymes include substrate and enzyme concentration, competitive & non-competitive inhibitors and, allosteric sites (Reece et al., 2012).
Enzymes are reusable biological molecules
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The spectrophotometer used in this lab is SPECTRONIC 21 MILTON ROY COMPANY. First it was turned on and 10 minutes were awaited for warm up. The wavelength was then set to 540 nm, after cleaning the outside of the measurement instrument with a Kimwipe to ensure accurate readings. The blank tube containing 5 mL of distilled water was put and, the spectrophotometer was calibrated, so the reading will only account for the solute absorbance. Subsequently the blank tube was inserted in the spectrophotometer, after the amount in grams of solute needed to prepare one litre of stock solution was measured. In addition the percent (%) w/v of the solution concentration was determined. Thereafter 1, 2, 3, and 4 mL(s) of stock solution were added to test tubes 1 to 4 in order, and each test tube was diluted with 4, 3, 2, and 1 mL(s) of distilled water accordingly (Table 1). After the diluted solution concentration and dilution factors were noted, the absorbance of all solutions was determined (Table 1). This information was later used to plot a graph of diluted solution concentration against absorbance at 540 nm (Figure …show more content…
The masking tape label was placed at the top of a test tube so it does not interfere with spectrophotometer’s readings, or vanish from heat treatment. Fifteen, ten, ten, and five drops of distilled water were placed in test tubes 1, 2, 3, and 4 accordingly. Following that, five, five, ten, and five drops of substrate starch solution were transferred into tubes 2, 4, 5, and 6 respectively. Furthermore five drops of enzyme were placed in test tube 3, 4, and 5, along with ten drops poured to test tube 6. This step was done rapidly as the reaction initiate as soon as the enzyme is added. In addition five drops of dinitrosalysicilic acid (DNSA) were added to all solutions, after and incubation period of 10 minutes. Again this was performed as quickly as possible, as DNSA reagent terminates the alpha- amylase enzyme reaction. The tubes were thereupon placed in a hot block set at 80_90°C, and 5 minutes were awaited to ensure that enzymes and substrates react. Next 5 mL of distilled water were pipetted and poured into each tube, upon inverting with a parafilm. The spectrophotometer was calibrated using test tube 1; the blank tube, and the wavelength control was set to 540 nm. The absorbance of every other test tube was measured and test tubes were handled carefully and cleaned with a kimwipe to avoid off readings (Table

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