Pearson Edexcel (9-1) GCSE Combined Science & GCSE Biology core practical - light and photosynthesis

Summary

In this Core Practical video, Mr. Osman from Claremont High School in London guides viewers through an experiment exploring how light intensity impacts photosynthesis. Using algae balls and a hydrogen carbonate indicator, students measure pH changes at varying distances from a light source to observe the rate of photosynthesis. The setup includes a control group and a negative control, with results recorded and analyzed to understand the process better.

Takeaways

• 🌱 Photosynthesis is the process by which green plants and some organisms like algae use sunlight to produce glucose and oxygen from carbon dioxide and water.
• 🔬 This experiment aims to explore how light intensity affects the rate of photosynthesis.
• 🏫 Mr. Osman, a science teacher at Claremont High School in London, is conducting the experiment.
• 🌟 Chlorophyll, a green pigment, plays a crucial role in the photosynthesis process by absorbing sunlight.
• 🧪 The experiment requires a controlled lab environment, eye protection, and various materials like PU bottles, algae balls, and a lamp.
• 📏 Different distances between the algae and the lamp (30, 40, 50, and 60 centimeters) are used to investigate the effect of light intensity.
• 🌡️ A heat filter and a water-filled clear container are used to control for heat, ensuring the experiment focuses on light intensity.
• 🕒 A negative control is set up by covering one bottle in kitchen foil to create a dark environment for comparison.
• ⏱️ The experiment runs for 60 minutes or longer to observe changes in the algae solution.
• 📊 The pH of the solution in each bottle is recorded and compared using an indicator scale to measure the rate of photosynthesis.
• 📋 Data obtained from the experiment is analyzed to understand the relationship between light intensity and photosynthesis.

Q & A

What is the main topic of the Core Practical video presented by Mr. Osman?

The main topic is the study of how light intensity affects the rate of photosynthesis.

What is photosynthesis and what role does chlorophyll play in it?

Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize glucose and oxygen from carbon dioxide and water. Chlorophyll is the green pigment that helps in capturing sunlight for this process.

What materials are needed to carry out the experiment as described in the video?

The materials needed include an area shielded from external light, eye protection, PU bottles and caps, a beaker of algae balls, a hydrogen carbonate indicator, a lamp with a heat filter, a meter ruler, a 10 milliliter measuring cylinder, kitchen foil, a stopclock, and a pipette.

What are the different distances between the algae and the lamp that Mr. Osman plans to investigate?

Mr. Osman plans to investigate distances of 30, 40, 50, and 60 centimeters between the algae and the lamp.

How many algae balls should be added to each bottle during the experiment?

10 to 15 algae balls should be added to each bottle.

What is the purpose of the heat filter in the experiment?

The heat filter is used to filter out the heat from the lamp, ensuring that only light, not heat, affects the algae.

How is the negative control set up in the experiment?

The negative control is set up by covering one bottle in kitchen foil to block all light, and placing it next to the bottle closest to the lamp.

How long should the lamp be turned on for the experiment?

The lamp should be turned on for at least 60 minutes.

What is the method for comparing the results of the experiment?

The colors of the solutions in the bottles are compared with an indicator scale, and the pH of the solution is recorded.

How is the change in pH per hour calculated for each bottle?

The change in pH per hour is calculated using the equation provided in the video script and the pH values recorded.

What should the students use to explain the data obtained during the experiment?

Students should use their knowledge of photosynthesis to explain the data obtained.