Percentage Calculations Quiz

To pellet out the protein.

To collect the precipitated protein.

To make the next concentration and repeat the process.

<p>It is a simple and cost-effective method for purifying proteins.</p> Signup and view all the answers

<p>It would lead to inaccurate enzyme activity assay results.</p> Signup and view all the answers

<p>To remove low molecular weight contaminants and salts.</p> Signup and view all the answers

<p>By measuring the rate of substrate conversion to product.</p> Signup and view all the answers

<p>To normalize protein amounts for further analysis.</p> Signup and view all the answers

<p>Ammonium sulfate is used to precipitate proteins based on their solubility. By adding increasing concentrations of ammonium sulfate, different proteins will precipitate out of solution, allowing for selective isolation.</p> Signup and view all the answers

<p>Dialysis separates proteins from smaller molecules like salts and buffers by utilizing a semi-permeable membrane. The membrane allows smaller molecules to pass through while retaining the larger proteins.</p> Signup and view all the answers

<p>A standard curve is a graph that relates known protein concentrations to their corresponding absorbance values. A blank is a sample containing all the reagents except the protein, used to zero the spectrophotometer and account for background absorbance.</p> Signup and view all the answers

<p>A control group is essential to establish a baseline for enzyme activity. It allows for comparison with experimental groups and ensures that any observed changes are due to the specific treatment being tested.</p> Signup and view all the answers

<p>As the protein concentration increases, the absorbance of the solution also increases. This relationship is typically linear within a certain range, forming the basis for the standard curve.</p> Signup and view all the answers

<p>Enzymes are sensitive to temperature changes. Maintaining a constant temperature ensures that the enzyme activity is measured under controlled conditions and avoids potential denaturation or inactivation of the enzyme.</p> Signup and view all the answers

<p>By plotting the enzyme activity (e.g., product formation rate) against substrate concentration, we can observe the enzyme's kinetic properties. The shape of the curve reveals the maximum activity, substrate affinity, and potential inhibition or activation.</p> Signup and view all the answers

<p>Each substance absorbs light at specific wavelengths. Choosing the correct wavelength ensures that the measurement is sensitive to the target molecule and minimizes interference from other components in the sample.</p> Signup and view all the answers

<p>Ammonium sulfate precipitation is a technique used to separate proteins based on their solubility. By adding increasing concentrations of ammonium sulfate, proteins with lower solubility will precipitate out of solution, allowing for their separation from other proteins.</p> Signup and view all the answers

<p>Dialysis is used to remove small molecules, like salts (e.g., ammonium sulfate) from a protein solution. It involves placing the protein solution in a semi-permeable membrane bag. The bag is then immersed in a large volume of buffer, allowing smaller molecules to diffuse out while retaining the larger proteins within the bag.</p> Signup and view all the answers

<p>Maintaining a low temperature during dialysis helps to minimize protein degradation and denaturation. Proteins are more stable at lower temperatures, reducing the risk of enzymatic activity or structural changes that could compromise the protein's functionality.</p> Signup and view all the answers

<p>Enzyme activity is typically measured by monitoring the rate at which the enzyme catalyzes a specific chemical reaction. This often involves measuring the disappearance of a substrate or the appearance of a product over time.</p> Signup and view all the answers

<p>The Bradford assay is a colorimetric method used to determine the concentration of protein in a solution. It relies on the binding of a dye (Coomassie Brilliant Blue G-250) to protein molecules, resulting in a color change that can be measured spectrophotometrically.</p> Signup and view all the answers

<p>Dissolving protein pellets in the appropriate buffer ensures the optimal pH and ionic strength for the enzyme activity and protein concentration assays. This helps to maintain the protein's structure and functionality, leading to accurate and reliable results.</p> Signup and view all the answers

<p>Changing the buffer during dialysis increases the concentration gradient of ammonium sulfate across the membrane. This accelerates the diffusion of ammonium sulfate out of the dialysis bag, effectively speeding up the removal process.</p> Signup and view all the answers

<p>Enzyme activity assays measure the catalytic activity of an enzyme, while protein concentration assays quantify the total amount of protein present. Enzyme activity assays focus on the function of the protein, while protein concentration assays provide a measure of the overall protein content.</p> Signup and view all the answers