Super Yeast

1
Super Yeast
2
Why did we do the lab?

• Apply steps of scientific method
• Apply key terminology of scientific method
• variables, controls, constants, hypotheses
• Data collection, data graphing and data analysis
• Hands-on scientific techniques and proper use of
  scientific equipment proper measuring
• Error analysis
• Introduction into biochemistry and cellular
  respiration

3
What we did well during the lab and not so
well?(error analysis)

• Correct procedures were followed
• Could go smoother if read ahead as instructed
• Excellent behavior in the lab setting on task
• Team work was great lots of helping one another
• Measurements pretty good, although some initial
  errors but corrections were made
• Ex. not adding any drops of sucrose at first and
  wondering why it wasnt changing color opps!

4
What we did well AFTER the lab and not so well?
(post lab write-ups need some work)

• First hypotheses need to be done before the
  experiment is performed. This WILL be checked
  next time.
• Graphing data titles, labels and units!
• Maximize graph space for best analysis of data

5
Compare graphs
6
Post lab reflection continued

• Analyzing data
• Does it support or not support your hypotheses?
• Your lab results do NOT prove anything just
  support or not support your prediction

7
Part 1 - reviewed

• Recap What were we trying to find out in part 1
  of the Super Yeast lab?
• Which type of sugar will cause the yeast to have
  the fastest rate of cellular respiration?
• How did we measure cellular respiration?
• CO2 bubble produced
• Biggest CO2 bubble fastest rate of cellular
  respiration

8
Review data for part 1

• Rate of cellular respiration was measured by?
• CO2 produced (mL)/ the time (min) __mL/min
• Do the calculations the solutions below stayed
  in the incubator for 10 mins.

Yeast and sugar solution Volume of solution remaining (mL) Volume of CO2 produced (mL) Rate of cellular respiration (mL/min of CO2)
Sample 1 with glucose 7.1 mL 2.9 mL .29 mL/min
Sample 2 with fructose 8.5 mL 1.5 mL .15 mL/min
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So what does the rate mean?

• Which yeast sample had the faster rate of
  cellular respiration according to the data?
• Sample 1 because it produced .29 mL of CO2 every
  minute
• Sample 2 only produced .15 mL of CO2 every minute

Yeast and sugar solution Volume of solution remaining (mL) Volume of CO2 produced (mL) Rate of cellular respiration (mL/min of CO2)
Sample 1 with glucose 7.1 mL 2.9 mL .29 mL/min
Sample 2 with fructose 8.5 mL 1.5 mL .15 mL/min
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Why would Sample 1 yeast be faster than Sample 2
yeast?

• Glucose was the better sugar for the yeast to use
  for cellular respiration when compared to the
  fructose
• Ok so now what question(s) should you be asking
  and answering?
• Why does glucose increase rate of cellular
  respiration for yeast?
• What is the difference between glucose and
  fructose?

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What is the difference between all of the sugars
in part 1 of Super Yeast lab?

• Such an important question we asked you twice!
• Glucose, fructose monosaccharides
• Sucrose disaccharides
• Starch polysaccharide
• Different structures different functions
• Glucose smaller, faster energy source, main
  energy molecule for all cells to break down

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Know and love glucose the sooner the better!
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Part 2 - reviewed

• Recap what were we trying to find out in part 2
  of the Super Yeast lab?
• Does the concentration of sucrose cause a faster
  rate of cellular respiration?
• How did we measure cellular respiration?
• Increase in CO2 causes increase in acid
• Measure how fast it turns acidic (blue to green
  using Bromothymol blue indicator)

14
Review data for part 2

• Rate of cellular respiration was measured by?
• time for color change to occur
• Faster color change faster production of CO2

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How would you graph the following data?
of drops of sucrose added to TT Time in mins/secs for color change TEAM Time in mins/secs for color change CLASS AVERAGE
0 - -
2 5 mins 20 sec 7 mins 30 sec
4 4 mins 15 sec 6 mins 20 sec
6 4 mins 1 sec 4 min 52 sec
8 3 mins 40 sec 3 min 58 sec
10 3 mins 5 sec 2 min 49 sec
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Variables

• Independent (x-axis)
• of drops of sucrose
• Dependent (y-axis)
• Time for color change
• Type of graph to make
• Line relationship between sucrose concentration
  and rate of cellular respiration (as measured by
  color change)

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Various amounts of sucrose drops added to yeast
solution and the time in minutes for the color
change
10
8
Red class average Blue team results
Time In Minutes for color change
6
4
2
0
2 4 6 8 10

Drops of 2 sucrose added to the yeast solution
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Was there a relationship between sucrose
concentration and rate of cellular respiration?

• Yes how did you know?
• More sucrose drops faster color change meaning
  CO2 was being produced at a faster rate.

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Cellular respiration two types presented in the
introduction of lab

• Aerobic- with oxygen
• C6H12O6    6O2  ----? 6CO2    6 H2O    36 ATP
• Anaerobic (aka fermentation) without oxygen
• C6H12O6 ----? 2CO2    2C2H5OH    2 ATP

YEAST CELLS DO BOTH TYPES OF CELLULAR
RESPIRATION!!!!!! What do they produce in each?
20
Controls vs constants

• Control for part 1?
• Distilled water added to yeast solution
• Control for part 2?
• Zero drops of sucrose added to yeast solution
• Purpose of having a control?
• Needed as a base or standard to compare the
  experimental groups

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Controls vs constants

• Constants for part 1?
• Amount of yeast, amount of sugar, time in
  incubator, temperature
• Constants for part 2?
• Amount of yeast, amount of indicator, start time,
  temperature
• What is the purpose of constants?
• To ensure that you are only testing one
  experimental variable

22
How would you test the effect of temperature on
cellular respiration in yeast?

• Question
• Background research on the effects of temperature
  on
• Hypothesis
• Materials
• Procedure
• Data to be collected (tables and calculations)

23
Review your lab

• What did you do well?
• What do you need to improve upon next time?
• Did you procrastinate?