Discussion: Enzymes Assessment
1. Fill in the following table. Compare all cups. Use relative terms to describe the size and number of bubbles in each cup. For instance, describe the Number of Bubbles using the terms: No bubbling, Moderate bubbling, Good bubbling, Very good bubbling. To describe average bubble size use the terms: Very small, Small, Large, or Very large. To describe pH without access to pH detectors, simply use the pH chart earlier in this chapter to describe each as acidic, neutral,or basic. To describe the Catalase Activity, use your data on the size and number of bubbles to estimate the amount of gas produced in the Catalase mediated process. Use the following terms: Very Low, Low, Moderate, High, Very high Discussion: Enzymes Assessment
Table 2.1. Catalase reaction observations.
Number of Bubbles Discussion: Enzymes Assessment
2. Bubbling indicates the formation of what chemical?
3. Describe the activity of Catalase as pH increases. Do you think that other enzymes are likely to behave in this way as well? Why or why not.
4. Assume that you have a pH meter which would enable you to very accurately measure the pH of a solution. Describe an experimental design that would allow you to pinpoint the exact pH at which Catalase is the most active.
5. Regarding cup #1:
a) Describe the utility of cup #1 as a control.
b) What other material did you introduce to this cup? Describe what you observed. How does Catalase activity in the material you investigated compare to potato?
Lab Summary (6p)
Lab Answers (14p)
1. List the following experimental materials:
a) Kind of yeast used:
b) Kind of water used:
c) Average temperature of the water bath during the experiment:
d) Average room temperature during the experiment (estimate if necessary):
e) Duration of yeast solutions exposure to bath:
2. List your results in Tables 3.1 – 3.4.
Table 3.1. Independent variables and experimental conditions.
height (in cm)
To be heated in warm water bath?
No. Leave this bottle at room temp.
Yes. Replicates bottle #2
Table 3.2. Observations of dependent variables.
Table 3.3. Balloon size and solution height measurements.
Uncertainty in C,
(long axis, R;
Uncertainty in R,
New height of
3. In Table 3.4, record yeast growth and estimated volume of each balloon on Bottles 1-6.
a. Yeast growth = New height (in Table 3.3) – Original height (in Table 3.1)
b. If the balloon did not inflate, it has a volume of zero.
c. To estimate the volume of each balloon, use the following formula for the approximate volume of an ellipsoid with a horizontal circumference C and long axis radius R (from Table 3.3):
Volume ? 2/19 × (C × C × R)
d. To estimate the fractional uncertainty in the volume, use this formula:
?V ? 2 × (?C +?R) / C
Table 3.4. Yeast growth and balloon volume.
1/3 teaspoon sugar
4. Outline the experimental questions in this yeast activity (in a paragraph or two).
5. Describe what is measured by the balloon volume. How does it correlate with yeast growth?
6. Compare Bottles # 2 & 3. Are they very different? Discuss the utility of having a duplicate measurement when considering the precision of your experimental technique.
7. Compare Bottles # 1 to 2 & 3 and discuss the effect of temperature on cellular respiration in yeast.
8. Compare Bottles # 2, 3, 4, 5 and discuss the effect of sugar on cellular respiration in yeast.
9. Discuss results obtained with your experimental Bottle #6 in comparison with the other experimental conditions.
10. In a paragraph or two, describe your conclusions, thoughts about what you learned about cellular respiration, and/or things that went wrong.
Unit 1 Home Lab 4: Genetics and DNA
Lab Summary (6p)
Lab Answers (14p)
1. Describe what you can see in the final DNA extraction solution. Is the precipitant bubbly or stringy? Does it stick together or does it form many islands?
2. List your phenotype for the tongue rolling, ear attachment, and hitch-hiker thumb traits in Table 4.1. Use the following notation:
a) If you can roll your tongue, then your phenotype is R. If you cannot, then your phenotype is r.
b) If your earlobes are unattached, then your phenotype is U. If your earlobes are attached, then your phenotype is u.
c) If you do not have a hitch-hiker thumb, then your phenotype is H. If you do have a hitch-hiker thumb, then your phenotype is h.
Use the information above to determine your possible genotypes and record them in Table 4.1. Notice that the phenotype for a given trait is recorded with a single letter, whereas the genotype requires two letters per trait.
Then, using what you have figured about your genotype, infer the different possible genotypes that your parents could have had. For instance, if you determine that your possible genotype for earlobe attachment is UU or Uu,then the possible parental genotypes are:
Possible parents of UU: UU ×UU; UU ×Uu; Uu × Uu
Possible parents of Uu: UU ×Uu; UU × uu; Uu × Uu; Uu × uu
For this question, do not ask your parents about their phenotypes! You will do this in question 3. Question 2 is an exercise in inference based on your understanding of genetics.
Table 4.1. Personal phenotype and genotype; inferred possible parental genotypes.
Inferred possible parental genotypes
(R or r)
(U or u)
(H or h)
3. Complete Table 4.2 for you, any blood relatives that you can ask (i.e., parents, siblings, children, etc.), and at least five unrelated “Others” (e.g., spouse, friends, co-workers, etc.). As before, phenotypes for a given trait are recorded with a single letter. You may wish to report separately on your children and spouse in Table 4.3.
Table 4.2. Observed parental, sibling, and other’s phenotypes,
(R or r)
(U or u)
(H or h)
In Table 4.2, are there any traits that are particularly common or uncommon among you and your relatives, compared to the unrelated others?