Biology

Effects of pH on enzyme-catalyzed reactions The pH (acidity) of the environment can affect the molecular bonds that maintain the shape of an enzyme’s “active site,” the site on the enzyme molecule responsible for binding to the substrate or substrates. A pH value of 2 is highly acidic, 7 is neutral, and 11 is highly […]

Effect of temperature on extent of browning Sample Temp (oC) Absorbance after ( ) minutes Any color changes? (see #11 below)   10. If you experience measuring delays, you will need to control for the fact that the reaction product continues to form while you are waiting to measure it. After measuring the absorbance in

PART II: EFFECTS OF ENVIRONMENTAL FACTORS ON RATE OF ENZYME-CATALYZED REACTIONS In this section you and a partner will design and carry out experiments to test the two hypotheses you made at the end of Part I concerning the effects of temperature and pH on enzymes. The quantitative techniques you will be using will allow

PART I: A SIMPLE ENZYME-CATALYZED REACTION When you cut open an apple, banana or pear, you cut through many cell walls and release the complex contents of many cells. Left exposed to the air, the white surface of the fruit will turn brown in a short time. This familiar color change is a good example

PART V: MEASURING LIVING CELLS 6.10 Exercise 10 – Preparing a wet mount of a naturally pigmented (red onion) cell. To view living cells under a microscope, you first have to “wet” mount them on a glass slide. Prepare wet mounts of onion cells as follows: 1. Place a clean microscope slide on a paper

PART IV: ESTIMATING THE SIZES OF CELLS When looking at objects through a compound microscope, it is difficult to get a feel for just how big (or small) they really are. We need some kind of “ruler”. The actual size of an object seen under the microscope can be estimated by first measuring the diameter

PART III: THE DISSECTING MICROSCOPE 6.5 Exercise 5 – Features of the dissecting microscope 1. Locate the dissecting microscope in your carrel or in the Central Study Area. Identify the major features of the dissecting scope: stage (for specimen), eyepieces, objective lens, zoom knob, focusing knob, and light sources above and below specimen (Figure 2).

Effect of PH on enzyme-catalyzed reactions Through the second experiment-effects of pH on enzyme-catalyzed reactions, we get PH and absorbance of whole 5 sample with the use and compare of blank sample. No.1 sample with PH 3 and the absorbance is 1.76. No.2 sample with PH 5 and the absorbance is 1.08. No.3 sample with

Effect of temperature on enzyme-catalyzed reactions Through the first experiment-effect of temperature on enzyme-catalyzed reactions, we get temp (°C), absorbance and color changes of whole 5 sample with the use and compare of blank sample. No.1 sample is in 0 °C, the absorbance after whole experiment ends is 2.34 and it change to yellow, not

Effects of pH on enzyme-catalyzed reactions Materials 1. 6 test tubes with a test tube rack 2. a wax pencil 3. a pipette 4. spec 20 5. potato extract 6. water 7. catechol 8. distilled water 9. 5 different buffer solutions (PH 3, PH 5, PH 7, PH 9, PH 11). Method 1. We use