BSC 197: Molecular and Cellular Basis of Life Lab

TA info

• Drinie Clairardin

• sgclair@ilstu.edu

• Office/Lab: SLB 245/247

• http://biology197.wikispaces.com/

Lab Info

• Lab schedule can be found on the syllabus– Course website: www.bio.ilstu.edu/bsc197

• Lab will consist of an exercise one day and a wet lab the following day

Lab Safety

• Safety is the number one priority

• ABSOLUTELY NO food, drink or tobacco in Lab

• Lab safety equipment available and will be used as needed (eg. Goggles, gloves)

• Location of Eyewash, fire extinguisher

• Do not endanger yourself or others

• Respect everyone in lab

Assignments• All lab reports must be typed (including graphs)• Do the lab report as follows

– Intro: Short background about the lab; include hypothesis

– Materials and Methods: Summarize briefly; focus on the reasons, don’t need exact details

– Results: tables/graphs of data and text to summarize what they show

– Discussion: analysis of results; troubleshoot lab if it didn’t work

– Conclusion: short summary of everything

• All lab reports are due at the beginning of the lab, two days after the lab was completed

Plagiarism Policy

• Plagiarism will not be tolerated – Consequences of being caught for plagiarism

include receiving a zero for the class and being referred to student affairs for disciplinary action

• Do your own work– Make your own graphs– Write your own papers– Cite sources

Exercise 1

• We will use several types of graphs in the lab– Bar (listed as column graph in excel): good

choice when only using a few data points; can have words in the x-axis; x-axis is not evenly numbered

Graphs (cont’d)

• Line Graph: used when you are looking at a change over time; x-axis not drawn to scale and x-axis can have letters

Graphs (cont’d)

• Scatter (XY Scatter): X-axis drawn to scale; data will be plotted in its exact position not just at the labeled point; can not be used if there are letters needed on the x-axis

Graphs (cont’d)

• Pie chart: Used when describing a part or percentage of a whole

Graphs (cont’d)

• Graph requirements:– X and Y axis titles, labels and units– Graph title (must be descriptive)– Legend

– Failure to include ALL requirements will result in point deductions

Statistical Calculations

• Pages 11-14 (top portion-not including T-Test)

• Mean- Average

N

XXXXXMEAN

...54321

•N = total number of replicates•X1, X2, X3… Individual data Points

Mean Calculation Example

• X1 = 79

• X2 = 85

• X3 = 92

• X4 = 87

• X5 = 93

• X6 = 99• (79 + 85 + 92 + 87 + 93 + 99)=535 • 535/6=89.17

Statistical Calculations (cont’d)

• Standard Deviation (S.D.)- measures variability of the mean

)1(

)()(*..

22

NN

XXNDS

•N- number of replicates•(X2)- Sum of the squares of X•(X)2- The square of the sum of the values for X

Standard Deviation (S.D.) Example Calculation

Larva # X

1 0.124

2 0.11

3 0.131

4 0.099

5 0.119

Larva # X X2

1 0.124 0.015376

2 0.11 0.0121

3 0.131 0.017161

4 0.099 0.009801

5 0.119 0.014161

Square X values

N = 5

Sum of X = 0.583

Sum of X2 = 0.068599 )15(5

)((0.583)-0.068599)(5..

2

DS

S.D.= 0.012461942

Statistical Calculations (cont’d)

• Standard Error (S.E.): estimates reliability of the mean

)(

.).(..

N

DSES

5

42)(0.0124619.. ES

S.E.= 0.005573149 = 0.006 (rounded off)

Statistical Calculations (cont’d)

• Do not round values until the end

• Show all your work for the calculations

For tomorrow:

• Exercise 1 due

• Lab 1: The Properties of Enzymes – Read Lab 1 in the manual

• Dress appropriately – No open toed shoes or shorts above the

knee!