Carly , Tyler , Cara

Rachyl , Candice , Kathryn

Katherine, Nicole, Keionna

Hailey , Angel , Alexandra

Michaela , Tamilla, Lindsay

Jacob, Jessica , Jordann,

Natalia

1a.) In a graph of absorbance vs. wavelength, explain what the area above the graph represents. (15 pts) b.) Explain what the purpose of cutting out and weighing the graphs was. How did you use this information in your lab report? (25 pts)  2.) Why is it reasonable to hypothesize that photosynthesis would work better in a non-green permitting solution? (roughly two sentences) (20pts) 3.) What material gives leaves their color? (Hint: it also used in photosynthesis) (10pts)Mitochondria b) Chlorophyll c) Electrons d) Polystyren 4.) DCPIP is a redox indicator and indicates when electrons are being stolen or not. When it receives electrons, it turns from BLUE to CLEAR. If it does not steal electrons, it stays blue.  Indicate below which states are true or false regarding the above information. (20 pts) ____________ If DCPIP turns clear, it has been reduced  ____________ If DCPIP stays blue, it is said to be reduced ____________ If a drug blocks electrons from reaching DCPIP, the color of DCPIP will become clear  ____________ If nothing blocks DCPIP from stealing electrons, the color of DCPIP will become clear

 4.) DCPIP is a redox indicator and indicates when electrons are being stolen or not. When it receives electrons, it turns from BLUE to CLEAR. If it does not steal electrons, it stays blue.  Indicate below which states are true or false regarding the above information. (20 pts) ____________ If DCPIP turns clear, it has been reduced  ____________ If DCPIP stays blue, it is said to be reduced ____________ If a drug blocks electrons from reaching DCPIP, the color of DCPIP will become clear  ____________ If nothing blocks DCPIP from stealing electrons, the color of DCPIP will become clear

Photosynthesis &e- transport

Photosynthesis &e- transport

Pathway thinkingPathway thinking

How? Why?

Evaluations

• What did you think of the semester (requires lab instructor to be gone)

6Goals for this lab

• Design an experiment given tools you know, a process you’ve looked at, and a straightforward goal

• DERIVE the purpose & implementation of ‘controls’ from your experiment

• SOLVE an actual question about the ‘invisible world’ through your experimental design & execution

What is DCPIP?• What are its uses

• What does it ‘indicate’

What is Vitamin C?

• What do you know about Vitamin C?

• It’s an anti...

9Putting a cork in it

• These tests confirm our claims for NEXT WEEK

• One more thing: confirming an herbicide is a photosynthecide

• 0.15ml herbicide/ml final*

• Blue one (DCPIP): 0.2 ml/ml*

• To your leaf disks!

*We’re gonna be a little sloppy: ignore the change in volume adding these produces.

First things first, testing DCPIP and

Herbicide

First things first, testing DCPIP and

Herbicide

• You will test the effect of DCPIP and Herbicide on photosynthesis

• Same approach as with the color permitting dyes

• DCPIP: 4mls DCPIP + 20 mls buffer• Herbicide: 3 mls Herb. + 20 mls buffer

• You will test the effect of DCPIP and Herbicide on photosynthesis

• Same approach as with the color permitting dyes

• DCPIP: 4mls DCPIP + 20 mls buffer• Herbicide: 3 mls Herb. + 20 mls buffer

X1

X2

Following the Scientific Approach: Predicting

The experiment’s afoot!

• Hypothesis I: The herbicide (‘X ’) acts before DCPIP has a chance to nab the electron

• Hypothesis II: The herbicide (‘X ’) acts after DCPIP has a chance to nab the electron

X1

• NO reduction of DCPIP (stays blue)

If we get this result, are we ready to publish a conclusion?

If we get this result, are we ready to publish a conclusion?

• Rampant reduction of DCPIP (turns clear)

X2

Technical aspects I

• Where’s the photosynthetic stuff?

• Round I: get rid of huge chunks of cellular debris

• Round II: acquire chloroplasts

What goes in the experiment

tube?

What can you ’conclude’ if the

DCPIP in the solution becomes clear?

What can you ‘conclude’ if the

DCPIP in the solution stays

blue?

HomeworkHomeworkCome Prepared the week of Nov. 26th!!!

Fill out the back side of this worksheet in DETAIL; use what you did today and the

protocol on pgs. 13-8 thru 13-12

Come Prepared the week of Nov. 26th!!!

Fill out the back side of this worksheet in DETAIL; use what you did today and the

protocol on pgs. 13-8 thru 13-12