Lab Experiment

1
Lab Experiment 2

• Scientific Method

2
Steps

• Observation
• Statement of problem (question)
• Inductive reasoning (specific detail to general
  statement)
• Hypothesis development (testable answer to
  question)
• Deductive reasoning (general statement to
  specific expectation)

3
Steps (cont)

• Experimentation
• Repeatable tests
• Variables
• Independent variable - controlled by researcher)
• Dependent variable(s) - result from changes in
  independent variable

4
Steps (cont)

• Experimentation
• Controls
• Includes all of the variables except the one to
  be tested
• Assay controls
• Positive control shows what a positive result
  looks like
• Negative control shows what a negative result
  looks like

5
Steps (cont)

• Results
• Results support or refute hypothesis. A
  hypothesis can never be proven
• Repeated verification and acceptance leads to a
  theory.

6
Activities

• Case study on childbed fever
• Experiment on sugar metabolism by yeast
• Identify the question
• Formulate a hypothesis
• Experiment
• Identify the control(s)
• Identify the variable(s)
• Record and examine your results

7
Yeast Experiment

• Fermentation rate slope of line
• Slope ?y/?x or (y2-y1)/(x2-x1)
• change in y / change in x
• Change in pressure / change in time
• ? Time 15 minutes
• ? pressure
• (pressure at 15 min) (pressure at 0 min)
• Logger Pro calculates the slope for you.
• Replication each variable (e.g., type of sugar)
  should be tested multiple times and an average
  taken

8
Short Report

• Complete the short report with observations
  (taken from introduction to sugar experiment),
  hypothesis (which you make up), results (which
  includes your data table) and discussion of
  results.
• Answer questions 1, 2, 4 and 6 from the
  conclusions page of the lab manual.