7 Enzymes II Background - LAB EXERCISE#7 All students...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 LAB EXERCISE #7 All students should download and print this document that contains background information on all the variables studied. All students are responsible for background information for the practical. Each student should only download and print the procedure document that applies to the variable his/her lab group is investigating. As stated previously, chemical reactions may be classified on a kinetic basis and enzyme kinetics is simply the study of rates . Chemical reactions are also classified on a kinetic basis by reaction order , and the reaction rate is influenced by the concentration of the reactants under a given set of conditions. There are those reactions that proceed at a rate exactly proportional to the concentration of one reactant (A B); reactions that have two reactants (A+ B C); and so forth. Enzymes are usually assayed by measuring initial reaction rate under conditions in which the enzyme is saturated with substrate and the pH and temperature are optimal. OBJECTIVE: The goal today is to do a comparative study between a baseline run and experimental runs. The results show how an enzyme behaves in a normal state to how it performs under various other conditions. The results are then visualized graphically. This section will address a few of the variables common to enzyme theory (know that whole courses are taught on this subject!) These variables assume that the enzyme is operating under normal conditions. BACKGROUND INFORMATION ON ALL THE INDEPENDENT VARIABLES STUDIED QUESTION 1: BACKGROUND ON HOW VARYING ENZYME CONCENTRATION AFFECTS THE REACTION RATE. In order to study the effect of increasing the enzyme concentration upon the reaction rate, the substrate must be present in an excess amount (i.e., the reaction must be independent of the substrate concentration). Any change in the amount of product formed over a specified period of time will be dependent upon the level of enzyme present. Experimentally, the effect of varying enzyme concentration upon the reaction rate is studied by observing changes in the initial velocity of the reaction . So that any variation of initial velocity observed reflects only differences of enzyme concentration, therefore, it is essential that the experiment be run at optimal pH and temperature; and there must be a constant amount of substrate present such that the enzyme is saturated during the initial period . From the Science Writing document, you would know these variables as the standardized variables (variables which must be kept constant through the experiment).
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Therefore, no enzyme means no reaction; more enzyme means the faster the reaction will proceed unless the reaction runs out of substrate. The independent variable is the enzyme concentration. The dependent variable is the reaction rate, velocity or enzyme activity. Shown graphically below, you see the concept of Velocity (V 0 ) vs. concentration of enzyme. FIGURE 1:
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/18/2011 for the course CHEMISTRY 209 taught by Professor Cohen during the Spring '11 term at Pittsburg State Uiversity.

Page1 / 9

7 Enzymes II Background - LAB EXERCISE#7 All students...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online