31 Bio 100 Lab Cellular Respiration Worksheet and Answers PDF

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Bio 100 Lab Cellular Respiration Worksheet and Answers...

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Cellular Respiration MATERIALS • Test tubes • Test tube rack • Graduated cylinder • Pipette • Aspirator • Balloon CHEMICAL REAGENTS • 2.5% sucrose solution • 5.0% sucrose solution • 10% sucrose solution • Phenol red • Yeast

PROCEDURE A. Yeast cellular respiration 1. Add 5 ml of 2.5% of sucrose solution to the test tube. 2. Add approximately ¼ tablespoon (15 ml) of yeast to the sucrose solution and gently swirl the test tube to allow mixing of the yeast with the sucrose solution. 3. Before positioning the balloon on top of the test tube, blow up the balloon a few times to stretch it out. 4. Allow the test tube be warmed in a warm water bath. 5. Observe how the balloon changes every five minutes for 20 minutes. 6. Repeat the procedures for 5% and 10% sucrose solutions. B. Effect of exercise on cellular respiration B1. 1. Measure approximately 10 ml of tap water and transfer to a test tube. 2. Using a dropper, add 4 drops of phenol red and swirl gently. 3. With the aid of a soda straw, blow into the solution until the solution changes color from red to yellow. Take account the time the solution changed color from red to yellow. Record your data in Table 1. 4. Perform the procedure on three different individuals with three trials each. Average the results and record on the corresponding table. 5. Count the number of breaths (1 breath = inhale + exhale) the individual takes for 1 minute. Do this for each trial per individual and record your data on Table 2. 6. While calculating the breathing rate, simultaneously count the number of pulses the individual takes in 30 seconds. Do this for each trial per individual and record your data on Table 3. B2. 1. Exercise, by doing jumping jacks, for exactly one minute. 2. Prior to the exercise, prepare the phenol red solution similar to the procedures in B1.

3. With the use of a straw, immediately exhale or blow into the phenol red solution after the one minute exercise. 4. Record the time it takes for the phenol red solution to change color from red to yellow in Table 1. 5. Immediately account the breathing and pulse rates of each individual as was performed in B1. 6. Repeat the procedures for a two minute exercise. GUIDE QUESTIONS 1. Why was it needed for the yeast suspension needed to be warmed? 2. What factors affect how much gas is created by the yeast? How do these factors effect gas production? 3. What water or room temperature helps the yeast create the most gas? Why? 4. What “yeast food” allows the yeast to create the most gas? Why? 5. How can exercise affect the required time for the phenol red solution to change color? How does phenol red work? 6. What is the correlation of breathing and pulse rates on the amount of carbon dioxide production? How do these factors affect carbon dioxide production?

Data Sheet Table 1. Carbon dioxide production (time of color change of phenol red). Student 1

Student 2

Student 3

Student 2

Student 3

Student 2

Student 3

Trial 1 Trial 2

Resting

Trial 3 AVERAGE 1 minute

Exercise 2 minutes

Table 2. Breathing rates of each individual per trial. Student 1 Trial 1 Trial 2

Resting

Trial 3 AVERAGE 1 minute

Exercise 2 minutes Table 3. Pulse rate of each individual per trial. Student 1 Trial 1 Trial 2

Resting

Trial 3 AVERAGE 1 minute

Exercise 2 minutes...