A.photosynthesis consumes carbon dioxide(co2)and produces oxygen(o2).brespiration consumes oxygen(o2) and produces carbon dioxide(co2)as a byproduct – lab report example

A. Photosynthesis consumes carbon dioxide(CO2)and produces oxygen(O2). Brespiration consumes oxygen(O2) and produces carbon dioxide(CO2)as a byproduct

Lab Report Experiment To Determine That Photosynthesis Consumes Co2 And Produces O2 As By-Product While Respiration Consumes O2 And Produces Co2 As The By Product.
Introduction
Photosynthesis is a process in which there is conversion of light energy to chemical energy in the chloroplast (Kalman, 2005). The process takes place in the presence of energy, given by light, required to trigger the reaction therein. The reaction involves water and CO2 and in the presence of light energy, sugar and O2 are formed as a by-product. The pigments of leave tend to absorb wavelengths of light from 400-700nm which is known as optimum wavelength of visible light spectrum for photosynthesis. On the other hand, respiration is the process by which breakdown of sugars for energy takes place in an organism (Kalman, 2005). It takes place in the mitochondria and the by-products are CO2, H2O and energy. Both cellular respiration and photosynthesis relates in that the by-products of each process is a raw material for the other process. The major purpose of the experiment is to determine that photosynthesis consumes CO2 and produces O2 as a by-product while cellular respiration consumes O2 and produces Co2 as a by-product.
Materials and methods
In photosynthesis experiment, five 50ml test tube were labelled 1, 2, 3, 4 and 5 using wax pencil. A piece of Elodea plant was placed in tube 1-4 while except 5. Tubes were filled to the brim with 7. 0 pH phenol red solution and then each tube was plugged with a rubber stopper. The surfaces of the tubes were wiped with paper towel. Tube 2 then wrapped using two sheets of cellophane, tube 3 wrapped using 2 sheets of green cellophane while tube 4 wrapped with one sheet of aluminium foil and tube 1 and 5 were not wrapped. The tubes were placed under bright white light for 11/2 hours and colour changes noted in each tube. In respiration experiment, goldfish was placed in a 50ml tube containing water with normal conditions for fish. The temperature of water was measured and the number of breaths of the fish per 60sec recorded. Tap water was poured into 600ml beaker and tube with the fish was transferred into the beaker. Small pieces of ice were added one by one to the beaker until the temperature drops to 100C then process stopped and number of breaths recorded. More ice was added until the temperature drops to 50C then cold water was changed and the procedure above repeated for the temperature of 210C and 250C.
Results
Table 1: change in colour of phenol red due to photosynthesis
Test tube
Solution colour at 0min
Solution colour at 90min
Solution color after 1 week
1 (white light)
Orange
Yellow
Orange
2 (red light)
Orange
Orange
orange
3 (green light)
Orange
Orange
yellow
4 (no light)
Orange
Orange
Orange
5 (control)
Orange
Yellow
Orange
Table 2:
Number of breaths
Temperature(0C)
Group1
Group2
Group3
Average
25
65
20
145
76. 67
21
55
26
104
61. 67
15(room)
85
19
114
72. 67
9
80
13
156
83
5
77
5
129
70. 33
Discussion
The colour of the phenol red turned to orange in all the tubes since the CO2 was absorbed from the environment within the enclosed tubes to react with water thus forming weak acid of pH around neutral hence the orange colour. But since tube 1 had all the factors responsible for photosynthesis thus Elodea took in CO2 within the tube to carry out photosynthesis thereafter lack of CO2 in water resulted for phenol red to react and changed the colour to yellow. The other tubes except tube 5 which is a control experiment lacked the visible light hence the pH remained at around neutral. The breathing rate is high at room temperature which is the optimal temperature for respiration and as the temperature falls further, the breathing rate reduces since the enzymes becomes inactivated.
Conclusion
It is learnt that photosynthesis is affected by light and the by-product is O2 and consumes CO2 while respiration is affected by temperature and its by-products is CO2 and water. While in the respiration experiment as the temperature goes down, the enzymes gets denatured and therefore loses their efficiency resulting to low number of breaths per 60 seconds
References
Kalman, B. (2005). Photosynthesis: Changing sunlight into food. New York, NY: Crabtree Pub. Co.