1 Enzymes - Level

2 1. Enzymes - Level I. Enzymes are proteins and have a 3D shape. II. Enzymes turn the food we eat into energy and unlock this energy for use in the body. III. Act as catalyst to accelerate a reaction. IV. Not permanently changed in the process.

3 1. Enzymes V. Enzymes are specific for what they will V. Enzymes are specific for what they will catalyze VI. Are reusable VI. End in – ase a. Examples: -Sucrase a. Examples: -Sucrase -Lactase -Lactase -Maltase -Maltase

4 1. Enzymes VII. How do enzymes work? a. Enzymes work by weakening bonds which lowers activation energy

5 1. Enzymes VIII. How do enzymes function? a. Enzymes attach to molecules called substrates, forming the enzyme-substrate complex: i. The substrate i. The substrate is the molecule that the enzyme acts upon. Enzyme Substrate Joins

6 1. Enzyme b. The substrate enters a specific location on the enzyme known as the active site. i. Active site: A restricted region of an enzyme molecule which binds to the substrate. Enzyme Substrate Active Site

7 1. Enzymes c. Induced Fit: A change in the shape of an enzyme’s active site i. Induced (started) by the substrate ii. A change in the configuration of an enzyme’s active site. Enzyme Active Site substrate induced fit

8 1. Enzymes Enzyme may be used again Enzyme- substrate complex E S P E E P Reaction coordinate

9 1. Enzymes IX. What Affects Enzyme Activity? a. Two factors: 1.Environmental Conditions 2.Enzyme Inhibitors

10 1. Enzymes 1.Environmental Conditions: A. Extreme Temperatures are the most dangerous. i. High temps may denature (unfold) the enzyme. B. pH (most like pH near neutral) C. Ionic concentration (salt ions)

1. Enzymes V. The pH scale is a measure of the concentration of hydrogen ions (H + ) in a solution. The scale runs from 0 – 14. Pure water has a pH of Basic solutions have pH values above Acidic solutions have a pH below Each number on the scale has 10 times the number of hydrogen ions as the number before it.

12 1. Enzymes 2. Two examples of Enzyme Inhibitors: a. Competitive inhibitors: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site. Enzyme Competitive inhibitor Substrate

13 1. Enzymes 3. Two examples of Enzyme Inhibitors: b.Noncompetitive inhibitors: Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site. Enzyme active site altered Noncompetitive Inhibitor Substrate

Enzymes