The affect of different pH levels on the rate of photosynthesis in plants Amber Pochert Angelica Popielarczyk Brice Gasche Molly Brocious

Background Info Enzymes have an optimal temperature and pH level at which they work. Anything less than or greater than that level will denature the enzyme. Enzymes have an optimal temperature and pH level at which they work. Anything less than or greater than that level will denature the enzyme. Independent variable- Cryptocoryne, we picked this plant because it is an aquatic plant and we thought it would be easier to test the pH. Independent variable- Cryptocoryne, we picked this plant because it is an aquatic plant and we thought it would be easier to test the pH.

Background Info cont. There have been other studies. They found that the pH of water used affects the plant’s rate of photosynthesis. There have been other studies. They found that the pH of water used affects the plant’s rate of photosynthesis.

What is the affect of pH levels of water on the rate of photosynthesis? The closer the pH level of the water is to 7 then photosynthesis will occur at a more optimal level. As the pH of the solution moves up and down the pH scale the enzymes in the plant will become denatured and will no longer be able to function resulting in less enzymes to continue photosynthesis. The closer the pH level of the water is to 7 then photosynthesis will occur at a more optimal level. As the pH of the solution moves up and down the pH scale the enzymes in the plant will become denatured and will no longer be able to function resulting in less enzymes to continue photosynthesis.

Procedure #1 1) Fill three 1000mL beakers with distilled water then add in the Cryptocoryne. Fill in the bottom of the beaker with gravel until the roots of the plant are covered. 2) Label the three beakers: Beaker #1= Acidic Beaker #2= Basic Beaker #3= Neutral Failed procedure

Procedure #1 cont. 3) Add in the distilled white vinegar into Beaker #1 until it has a pH of around 3. 4) Add in the Sodium Hydroxide into Beaker #2 until it has a pH of around 10. 5) Let the plants soak in the solution for three days. 6) Remove plants and conduct a leaf disk test to see how the solutions affected their photosynthesis.

Procedure #2 1) Fill three 1000mL beakers with water then add 6 spinach leaves to each of the three beakers. 2) Label the three beakers: Beaker #1= Acidic Beaker #2= Basic Beaker #3= Neutral

Procedure #2 cont. 3) Add in the distilled white vinegar into Beaker #1 until it has a pH of around 3. 4) Add in the Sodium Hydroxide into Beaker #2 until it has a pH of around 10. 5) Let the plants soak for three days. 6) After one day remove two leaves from each beaker and conduct the leaf disk test.

Procedure #2 cont. 7) After the second day remove two leaves from each beaker and conduct the leaf disk test. 8) After the third day remove two leaves from each beaker and conduct the leaf disk test.

Data

Data cont.

The basic and acidic pH levels did denature the enzymes to the point where they weren’t able to perform photosynthesis as well as neutral. The basic and acidic pH levels did denature the enzymes to the point where they weren’t able to perform photosynthesis as well as neutral. For neutral vs. acidic the P-value= For neutral vs. acidic the P-value= For neutral vs. basic the P-value=0.102 For neutral vs. basic the P-value=0.102

Limitations Keeping the plants alive. Keeping the plants alive. Only having class time. Only having class time. Having a limited amount of time to work with our plants because of the absence of the teacher. Having a limited amount of time to work with our plants because of the absence of the teacher.

Implications Our findings support our hypothesis that water with a neutral pH level is better for a plant’s rate of photosynthesis. Using acidic or basic pH levels will result in a slower rate of photosynthesis, or none at all. Our findings support our hypothesis that water with a neutral pH level is better for a plant’s rate of photosynthesis. Using acidic or basic pH levels will result in a slower rate of photosynthesis, or none at all.

Credits Mrs. Coury Mrs. Coury Mentor Anton Baudoin (he had an awesome beard!) Mentor Anton Baudoin (he had an awesome beard!)