Enzyme+Substrate+reaction+(class+activity)

** SIMULATING THE ENZYME-SUBSTRATE MODEL **
OBJECTIVES ** = = = =
 * 1) To study reaction rates of an enzyme-mediated reaction
 * 2) To study the effects of an environmental variables on enzyme function
 * 3) To collect, graph, and analyse data relating to the reaction

=
**Apparatus: PROCEDURE** =====
 * 1) 16 pairs of black/white balls
 * 2) 10 coloured balls
 * 3) Muskin Tape
 * 4) Tennis ball
 * 5) Stopwatch
 * 6) Box

** Trial 1 **

 * 1) Divide into teams of four students each.
 * 2) Place 16 pairs of black/white balls and 10 coloured balls into the opaque box.
 * 3) The balls represent two different molecules in a solution, one of them represents water molecule.
 * 4) One student in the group is assigned to be a picker, counter, recorder and timer.
 * 5) The picker will reach in the box without looking at the content to pick up a pair of balls.
 * 6) If it is a pair of coloured balls, throw it back into the box and grab another pair of balls.
 * 7) If it is a pair of black/white balls, pull the balls apart and hand them to the counter.
 * 8) The counter will count the number of pairs of black/white balls that she has separated.
 * 9) At every 10 seconds, the timer will call out the time so that the recorder could write down the accumulated number of pairs that have been separated (sum of all previously separated) in **table 1**. //E.g. if in the first 10 seconds (1 - 10) 2 pairs of balls are separated and in the next 10 seconds another 2 are separated, it should be entered as 4 in the row 10 - 20.//
 * 10) Repeat this till all 16 pairs of black/white balls have been separated.

** Trial 2 **

 * 1) Fix all the black/white balls to form the 16 pairs and throw them back into the box.
 * 2) Remove six pairs of the coloured balls. Shake to mix the balls.
 * 3) Repeat step 6 – 9 from trial 1 and record the data.

** Trial 3 **

 * 1) Fix all the black/white balls to form the 16 pairs and throw them back into the box. Put in all the coloured balls that were taken out.
 * 2) Repeat step 6 – 9 as before but this time the picker will have the help of one of the teammate.
 * 3) The picker only needs to pick the right pair of balls and hand it to the one of the teammate to separate it.
 * 4) Proceed till all black/ white balls have been separated.

** Trial 4 **

 * 1) Prepare for the new trial as before.
 * 2) Shake to mix the balls.
 * 3) Tape the thumb and four fingers of the picker’s hand securely together.
 * 4) Use this hand to pick the balls from the box and repeat the process as in step 6 – 9 and record the data in **table 1**.
 * 5) Stop after 100 seconds or when all the black/white balls have been separated, whichever comes first.

**Trial 5**

 * 1) Mix all the pairs of balls in the box as before.
 * 2) In this last trial, the picker is handicapped by taping a tennis ball to the palm of the hand to be used for picking.
 * 3) Repeat step 6 – 9 and stop after 100 seconds when all the black balls have been separated, whichever occurs first.

**Table 1 – Team Data**

 * **Time Periods** || **Trial 1** || **Trial 2** || **Trial 3** || **Trial 4** || ====**Trial 5**==== ||
 * **0 – 10** || 3 || 3 || 5 || 0 || 1 ||
 * **10 – 20** || 6 || 7 || 9 || 0 || 1 ||
 * **20 – 30** || 7 || 8 || 14 || 0 || 1 ||
 * **30 – 40** || 9 || 9 || 16 || 0 || 1 ||
 * **40 – 50** || 12 || 14 || 16 || 1 || 1 ||
 * **50 – 60** || 16 || 16 || 16 || 1 || 1 ||
 * **60 – 70** || 16 || 16 || 16 || 1 || 1 ||
 * **70 – 80** || 16 || 16 || 16 || 2 || 2 ||
 * **80 – 90** || 16 || 16 || 16 || 3 || 2 ||
 * **90 - 100** || 16 || 16 || 16 || 4 || 2 ||

Class Data: Time Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 1 - 10 17 31 5 5 58 10 - 20 36 58 9 9 112 20 - 30 49 79 14 14 156 30 - 40 68 98 16 16 198 40 - 50 82 107 16 16 221 50 - 60 96 111 16 16 239 60 - 70 107 112 16 16 251 70 - 80 109 112 16 16 253 80 - 90 111 112 16 16 255 90 - 100 96 112 16 16 240

Refer to graph: https://spreadsheets.google.com/ccc?key=0Aqm72wNcBFpWdGNadmlabEh3ZlB1Y25JbjN2aWR4N2c&hl=en# **DISCUSSION**

In this activity, state what the following was represented by and explain your reason for suggesting it in your online journal. > =** ANALYSIS **= Create a new table using a new Excel file. Combine the data from each group to obtain a class data. Record the totals for each trail at each time interval. Plot a graph of total numbers (Total #) of each trial vs final time of each time period. This will result in a graph with five lines illustrating the five sets of trial data.
 * 1) Enzyme: Picker's hand. It was responsible for separation of the balls.
 * 2) Substrate: Black / white balls. They would be separated by the hand.
 * 3) Water: The coloured balls.
 * 4) Coenzyme: The team member that helps to separate the balls. This helped to speed up the process.
 * 5) Competitive inhibitor: The taped fingers / tennis ball. They altered the hand's ability to separate the balls.

** QUESTIONS **
//Answer these questions in your online journal.// 1. In **trial 1**, why did the rate eventually decrease? What could have been added to maintain the initial rate? As the reaction took place over time, the amount of remaining substrate increased, hence it was harder for the enzyme to break them down as they were few in number. More substrates could have been added to maintain the initial rate. 2. If a huge number of black balls were added will it change the maximum rate? Why? Yes. This is because the reaction would occur at a faster rate, given there is a higher concentration. 3. Coloured balls were removed in **trial 2**. What does this simulate? How does that affect the rate of enzyme reaction? This simulates a higher concentration of substrates in water. The enzyme reaction rate will increase. 4. How else could you change the rate of reaction? Making the solution of substrate more dilute. 5. Why does an active site not work as well if its active site is changed? The substrate cannot fit properly into the active site, and hence little or no reaction can take place. 6. What environmental factors affect enzyme shape? pH, temperature 7. How might chemical affect you if they act like the tennis ball during your bodily reactions? It could cause serious disorders, even death.