Absorbance Measurement and Fermentation Basics

Stop the timer and turn off the lamp.

Every 2 minutes for a total of 14 minutes.

To investigate its effect as an inhibitor on the Hill reaction of photosynthesis.

<p>Add 0.2 mL of DCMU stock to 1.8 mL of RO water and vortex to mix.</p> Signup and view all the answers

<p>2 mL buffer, 1 mL DCPIP, and 1 mL Stock DCMU.</p> Signup and view all the answers

<p>To ensure thorough mixing of the solutions for accurate results.</p> Signup and view all the answers

<p>Rinse the tubes and cuvettes and leave them upside down to dry.</p> Signup and view all the answers

<p>They provided nutritious, carbohydrate-rich, and safe options for consumption when food was scarce or unsafe.</p> Signup and view all the answers

<p>Saccharomyces ferments carbohydrates to produce ethanol and carbon dioxide, which is essential for alcohol production and causes bread to rise.</p> Signup and view all the answers

<p>The ethanol evaporates during the baking process.</p> Signup and view all the answers

<p>Carbohydrates serve as the energy and carbon source for yeast during fermentation.</p> Signup and view all the answers

<p>They must first be broken down into simple sugars like glucose.</p> Signup and view all the answers

<p>The reaction represents glucose being converted into ethanol and carbon dioxide in the presence of water.</p> Signup and view all the answers

<p>It is now used to produce ethanol fuel, maximizing efficiency and resource utilization.</p> Signup and view all the answers

<p>Sugarcane, corn, and barley are mentioned as substrates for fermentation.</p> Signup and view all the answers

<p>Sodium carbonate is added to stop the reaction by inactivating the enzyme.</p> Signup and view all the answers

<p>They should be reported as 1.00.</p> Signup and view all the answers

<p>Add 3.5 mL phosphate buffer and 0.5 mL of the appropriate ONPG solution to each tube.</p> Signup and view all the answers

<p>Staggering the addition helps prevent all tubes from completing the reaction at the same time, allowing for accurate measurement of each sample.</p> Signup and view all the answers

<p>The blank tube is used to zero the spectrophotometer, ensuring accurate measurement of absorbance for the reaction tubes.</p> Signup and view all the answers

<p>They should be reported as 0.000.</p> Signup and view all the answers

<p>Rinsing the cuvette prevents cross-contamination between samples, which can skew absorbance readings.</p> Signup and view all the answers

<p>To create an airtight seal that prevents air leaks and ensures accurate measurement.</p> Signup and view all the answers

<p>The three positions are 'At Rest' (idle), 'Stop 1' (measures the selected volume), and 'Stop 2' (blows out the last drops).</p> Signup and view all the answers

<p>Immerse the tip approximately 3 mm into the liquid while holding the micropipette vertically.</p> Signup and view all the answers

<p>Gliding back slowly helps create a consistent and accurate volume measurement without allowing air bubbles.</p> Signup and view all the answers

<p>The blow-out ensures any remaining liquid in the tip is expelled completely.</p> Signup and view all the answers

<p>Hold the micropipette over the disposal bag and depress the eject button carefully to shoot the tip off.</p> Signup and view all the answers

<p>Exceeding volume limits can damage the micropipette and lead to inaccurate measurements.</p> Signup and view all the answers

<p>The presence of other absorbing molecules in the solution can interfere with the measurements.</p> Signup and view all the answers

<p>The purpose is to determine a proper concentration of b-galactosidase that allows for measurable enzyme activity without being too diluted or too concentrated.</p> Signup and view all the answers

<p>They should be labeled according to their dilution factors, such as 1:10, 1:100, 1:1000, etc.</p> Signup and view all the answers

<p>Staggering the time ensures that each reaction has a distinct incubation time, allowing for accurate measurement of absorbance at the same time interval.</p> Signup and view all the answers

<p>Sodium carbonate is used to stop the reaction after a set incubation period, allowing for consistent measurement of absorbance.</p> Signup and view all the answers

<p>The cuvette must be wiped with a Kimwipe to ensure that there are no smudges or contaminants affecting the absorbance reading.</p> Signup and view all the answers

<p>The concentration is determined using a standard curve that correlates absorbance to o-nitrophenolate concentration.</p> Signup and view all the answers

<p>The reaction rate is calculated by dividing the concentration of o-nitrophenolate produced by the time interval, typically in minutes.</p> Signup and view all the answers

<p>Using a blank solution ensures that the spectrophotometer readings account for the background absorbance of the reagents, providing accurate measurements of the samples.</p> Signup and view all the answers

<p>10</p> Signup and view all the answers

<p>10 mg mL−1</p> Signup and view all the answers

<p>Volume of the original or stock solution.</p> Signup and view all the answers

<p>50 µL</p> Signup and view all the answers

<p>Terrestrial and aquatic plants, water chemistry, and aquatic microorganisms.</p> Signup and view all the answers

<p>Cd = Cu × D</p> Signup and view all the answers

<p>To compare and analyze how fertilizer impacts different ecosystems.</p> Signup and view all the answers

<p>It is the total volume of the solution; it represents the degree of dilution applied.</p> Signup and view all the answers

Dilute DCMU stock solution 1:10 using RO water.

Dilute a 1:10 DCMU solution 1:10 using RO water.

Contains buffer, water, and DCPIP but no DCMU.

Transfer chloroplast solution to labeled cuvettes, seal with parafilm, and invert to thoroughly mix.

Measure change in absorbance of DCPIP over time in the presence and absence of DCMU.

A chemical herbicide that inhibits photosynthesis.

Use a spectrophotometer to determine the absorbance of light by a substance.

Measure absorbance of Cuvette #3 solutions every 2 minutes for 14 minutes.

A process where yeast converts carbohydrates into ethanol and carbon dioxide.

Sugars like glucose that yeast can directly use for fermentation.

Larger molecules like starch that need to be broken down into simple sugars first for fermentation.

Components like cellulose, that plants use to build their structures, harder to ferment.

Microscopic organisms that are used for fermentation to produce desirable outputs.

The ethanol and CO2 created during the fermentation of carbohydrates by yeast

A simple sugar that is a crucial part of fermentation.

Ethanol with a purity of 200 proof (100%) and an additive so alcohol tax is avoided.

A solution containing o-nitrophenyl-β-D-galactopyranoside, used in enzymatic reactions.

A solution maintaining a stable pH in enzymatic reactions.

A solution containing the enzyme to be tested in Part 1.

A control tube containing all components except substrate or enzyme, used as a reference for measuring absorbance.

The speed at which the substrate is broken down by the enzyme.

A device measuring the absorbance of light by a solution.

An unknown chemical substance used to determine its effect on enzyme activity (as inhibitor).

A solution used to stop the enzymatic reaction.

The tip must be placed securely on the micropipette barrel to ensure a tight seal and prevent leakage of air or tip detachment.

The control button has three positions: "At Rest" for inactivity, "Stop 1" to measure pre-selected volume, and "Stop 2" for expelling last drops when transferring liquid.

Attach the tip, press to the first stop, immerse vertically, release slowly, slide out of solution, and discard.

Position tip carefully in the receiving vessel, press to first stop, press to second stop for complete expulsion, remove the tip slowly.

Discard used tips into designated disposal bags.

0.1 milliliter (mL) is equal to 100 microliters (μL), and 1.0 mL is equal to 1000 μL.

Handle micropipettes carefully to avoid damage or dropping. Store in the provided stands when not in use.

Ensure your solution doesn't contain unwanted molecules absorbing light, since this will cause inaccuracies in your experiments.

A method of progressively diluting a solution by a constant factor, creating a series of solutions with decreasing concentrations.

The rate at which an enzyme catalyzes a specific reaction, measured by the amount of product formed per unit time.

To determine the optimal concentration of the enzyme for an experiment, ensuring it's neither too diluted nor too concentrated for accurate measurement.

A graph that relates the absorbance of a solution to the concentration of the substance being measured.

A yellow-colored product produced by the enzyme b-galactosidase, used to measure enzyme activity.

A small portion of a larger sample taken for analysis or testing.

The ratio of the volume of the original solution to the total volume of the solution after dilution. It represents the fraction of the original solution present in the diluted solution.

The total volume of the diluted solution, which is the sum of the original solution volume and the diluent volume.

The concentration of the substance in the diluted solution, calculated by multiplying the undiluted concentration by the dilution.

The concentration of the substance before dilution, also known as the stock solution concentration.

A formula used to calculate dilutions, where V1 is the volume of the stock solution, C1 is the concentration of the stock solution, V2 is the volume of the new solution, and C2 is the concentration of the new solution.

Cd = Cu × D, where Cd is the concentration of the diluted sample, Cu is the concentration of the undiluted sample, and D is the dilution.

The process of determining the ratio of the original solution volume to the total volume of the solution after dilution.

The process of making a solution with a lower concentration by adding a diluent to a stock solution.