Phtosynthesis And Respiration

Essay by EssaySwap ContributorHigh School, 12th grade February 2008

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Purpose: The purpose of these experiments is to compare the two processes of photosynthesis and respiration and to find out what they do.

Equipment: Photosynthesis Disposable gloves, lab apron, safety goggles, two 5 cm sprigs of elodea, three 250 ml flasks, water, Bromothymol Blue (Ph indicator), rubber bands, drinking straw, plastic wrap, 100 ml graduated cylinder Respiration Disposable gloves, safety goggles, lab apron, 250 ml flask, 100 ml graduated cylinder, phenolphthalein solution, pipet, drinking straw, water, clock, sodium hydroxide solution Procedure: Photosynthesis Put on safety goggles, lab apron, and gloves. Label the flasks #1, #2, and #3. Put 200 ml of water and 20 drops of Bromothymol Blue into each flask. Put drinking straw in flask #1 and blow into blue solution until it turns yellow. In flask #2 do the same as in flask #1. Put one elodea sprig into flask #1 and the other one into flask #3.

Do nothing to flask #2. Cover flasks with plastic wrap and secure with a rubber band. Leave flasks in a well-lighted area and leave them overnight. Record observations.

Respiration Put on safety goggles, lab apron, and gloves. Put 50 ml of water and four drops of phenolphthalein to the flask. Using the drinking straw, gently blow into the solution for 1 minute. Add the sodium hydroxide one drop at a time, and gently swirl the flask. When the liquid turns pink, stop adding drops. Record the number of drops you used. Run around for 2 minutes and repeat from blowing into the solution with a straw.

Data: Photosynthesis Flask # Thursday Friday Monday 1 Yellow Clear Clear 2 Yellow Yellow Yellow 3 Blue Blue Blue Respiration Before exercise After exercise 15 Drops 30 Drops There was a 100% increase in the amount of drops it took to turn...