Photosynthesis & Respiration LAB

Complete the lab (questions & charts) before Sunday.

Photosynthesis & Respiration

Exercise 1 – Photosynthesis Part 1

Bag mass ____ g + 1.5 g NaHCO3 = ____ Final mass (g)

Data Table 1. Photosynthetic rates.

Rate

Distance (mm)

Solution starting measurement

Net photosynthesis

Respiration

Gross photosynthesis (net photosynthesis + respiration)

Rate of photosynthesis (gross photosynthesis / 10 min)

Questions:

A. What molecules did the plant produce when exposed to light?

B. What resources were consumed to produce the molecule?

C. What part did light play in the reaction?

D. What molecule was consumed by the plant while it was in the dark?

Plants consume Oxygen molecule (O2) . But oxygen can only be consumed in conjunction with fuels to oxidize: glucose, amino acidsand fatty acids at night in the process of respiration. 

E. What molecule was produced by the plant while it was in the dark?

 In the dark, at night, plants respire just as we do, taking oxygen molecules and glucose to produce ATP and carbon dioxide – the later released as a gas

F. Where did the molecules go that were produced in the dark?

G. What critical service do plants provide humans?

H. Would animal life on Earth be possible without plants?

I. Would any life on Earth be possible without sunlight?

Exercise 2 – Photosynthesis Part 2

Data Table 2. Respiration results.

Experimental

Conditions

Starting distance (mm)

Final distance (mm)

Change in movement

(mm)

Time (min)

With Elodea

Without Elodea

Questions:

A. When you blew through the straw into the Bromothymol blue solution, what gas did you add? What color change did you observe in the solution and why?

B. What color change occurred after you placed the plant into the respirometer and turned on the light?

C. What was happening when the solution in the horizontal tubing started to move?

D. How long did it take the color change to occur after the solution started to move?

E. Why did the color change?

F. When you repeated the experiment without a plant in the respirometer, what happened and why?