Final answer:
To determine if photosynthesis has occurred, a pH indicator such as bromothymol blue can be used. It initially colors the water blue and would change to green or yellow if photosynthesis occurs, indicating a higher pH due to the absorption of carbon dioxide. The process requires sunlight, carbon dioxide, water, and occurs in the chloroplasts of plant cells.
Step-by-step explanation:
To determine whether photosynthesis has occurred, you can use a substance like bromothymol blue (BTB), which is a pH indicator that changes color in response to changes in pH level. Initially, BTB colors the water blue. If photosynthesis has occurred, the water would become less acidic due to the uptake of carbon dioxide, causing the BTB to change to a greenish or yellow color, signaling a higher pH.
For photosynthesis to occur, specific conditions and substances are necessary. Plants require sunlight, carbon dioxide from the air, and water absorbed through their roots. These substances come together primarily in the chloroplasts of plant cells to generate glucose and oxygen, with the oxygen being released as a byproduct.
Cellular respiration needs glucose and oxygen to produce ATP (adenosine triphosphate), the cell’s energy currency and releases carbon dioxide and water as waste products. ATP is vital for cellular functions as it provides energy for cells to carry out various processes. Autotrophs, like plants, also perform cellular respiration because they use the glucose produced during photosynthesis to produce ATP for their own energy needs.
The raw materials for photosynthesis, carbon dioxide, and water, are absorbed from the air and soil, with the light-dependent reactions occurring within the thylakoid membranes of chloroplasts. Chlorophyll, the pigment in plants, absorbs light primarily in the blue and red wavelengths, facilitating the energy absorption needed for photosynthesis.