7. Definition of Enzymes Enzymes are biological catalysts that alters/speed upthe rate of a chemical reaction and remains chemically unchanged at the end of reaction.
8. Definition of Enzymes made of proteins Enzymes are biological catalysts that alters/speed upthe rate of a chemical reaction and remains chemically unchanged at the end of reaction. ^
9. Enzyme in action Substrates Enzyme Enzyme-substrate complex + products + Active sites
12. Properties of an enzyme Speeds up chemical reaction Required in small amounts Highly specific in action Work best at their optimum temperature and pH May need co-enzymes for activity
13. Properties of an enzyme Speeds up chemical reaction Required in small amounts Highly specific in action Work best at their optimum temperature and pH May need co-enzymes for activity
14. Enzymes are Highly Specific In Action Each chemical reaction in a cell is catalyzed by unique enzyme(s). Sucrose Sucrase Lipid Lipase
17. Lock & Key Hypothesis Presence of Active sites (depressions) Substrates fit into active site of enzyme Enzyme = lock; Substrate = key shape of substrate complementary to shape of enzyme.
18. Properties of an enzyme Speeds up chemical reaction Required in small amounts Highly specific in action Work best at their optimum temperature (practical) and pH May need co-enzymes for activity (FYIO) Both properties and factors affecting enzymes
28. Toothpickase activity Directions: Get into pairs. Each pair will receive 70 toothpicks and a stopwatch. Use 35 toothpicks for part I and 35 toothpicks for part II. 1 person will be the ‘breaker’ the other the timer. Do only pg 1 & 2 in class…
29. What can you deduce from the ‘Toothpickase’ activity? If enzyme concentration increases, number of products form increases.
30. Questions to think about What if you only had 10 toothpicks for the activity? What happens to the rate of enzymatic reactions at very cold and very high temperatures? What are some of the properties of the enzymes that are found in the human stomach?
31. Summary Enzyme definition Enzymes are biological catalysts made of protein that alters/speed upthe rate of a chemical reaction and remains chemically unchanged at the end of reaction. Properties of Enzymes Speeds up Small/minute amounts Highly specific in action Work best at their optimum temperature and pH May need co-enzymes for activity Factors affecting Enzyme Activity -Temperature - pH - Substrate Concentration - Enzyme Concentration
32. Homework Complete ‘Toothpickase’ WS 3. Do workbook Ex 3.2 ‘Enzymes’ pg 29-32 by tomorrow (fri 12th Mar 10). Explore ‘Factors affecting enzyme rate of reaction’ website http://www.kscience.co.uk/animations/model.swf Read up textbook pg 77-85 to prepare for short quiz next lesson to prepare for quiz when school re-opens.
33. Next Lesson Tips for experiment on “Effects of temperature on amylase (enzyme) activity”
![Lesson Review Definition of Enzymes Properties of Enzymes ,[object Object]](https://image.slidesharecdn.com/nasenzymeslesson2-100312014623-phpapp02/85/Nas-Enzymes-Lesson-2-1-320.jpg)
