Blog

A substance that releases hydrogen ions (H+) in solution is known as:

Which of the following terms describes a molecule that is attracted to water?

In a laboratory experiment using spectrophotometry, an enzyme is combined with its substrate at time zero.  The absorbance of the resulting solution is measured at time zero and at five-minute intervals.  In this procedure, an increase in absorbance is related to the amount of product formed during the reaction.  The experiment is conducted using the three preparations shown in the table below. Absorbance of Solution at different times Enzyme Preparation 0 min 5 min 10 min 15 min 20 min I.    3 mL of enzyme preparation    2 mL of substrate   pH 5.0 0.0 0.22 0.33 0.38 0.37 II.    3 mL of boiled enzyme preparation      2 mL of substrate      pH 5.0 0.0 0.06 0.04 0.03 0.04 What is the constant (standardized) variable of this experiment? Check all that apply.

If a substance has a pH of 6, it is considered …

The diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to bacteria?

If the shape of an enzyme’s active site is altered, it can result in:

The following questions refer to an experiment in which a dialysis-tubing bag is filled with a mixture of 3% starch and 3% glucose and placed in a beaker of distilled water, as shown below. After 3 hours, glucose can be detected in the water outside the dialysis-tubing bag, but starch cannot.     If, instead of the bag, a potato slice were placed in the beaker of distilled water, which of the following would be true of the potato slice?

In a laboratory experiment using spectrophotometry, an enzyme is combined with its substrate at time zero.  The absorbance of the resulting solution is measured at time zero and at five-minute intervals.  In this procedure, an increase in absorbance is related to the amount of product formed during the reaction.  The experiment is conducted using the three preparations shown in the table below. Absorbance of Solution at different times Enzyme Preparation 0 min 5 min 10 min 15 min 20 min I.    3 mL of enzyme preparation    2 mL of substrate   pH 5.0 0.0 0.22 0.33 0.38 0.37 II.    3 mL of boiled enzyme preparation      2 mL of substrate      pH 5.0 0.0 0.06 0.04 0.03 0.04 What is the independent variable of this experiment?

Feedback inhibition is

To study the actions of the enzyme catalase on hydrogen peroxide, students performed the following experiment.  Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water.  The filtrate was stored on ice.  The following hydrogen peroxide solutions were made: 1 %, 5%, 10%, and 15%. Filter paper disks were soaked in the catalase filtrate and dropped into beakers containing the various solutions.  The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction.  The following data were obtained. Time it takes for disks to float in different Hydrogen Peroxide concentrations Hydrogen Peroxide Solution Average Time, in seconds, for disks to float 1% 30 sec 5% 25 sec 10% 20 sec 15% 10 sec If the potato solution was boiled for 10 minutes and cooled for 10 minutes before being tested, the average time for the disks to float to the surface of the hydrogen peroxide solution would be