Spinach Lab Report

When tasked to measure the rate of photosynthesis among spinach leaves , we were given a large choice of lightbulbs of varying color, size, intensity, and so forth. The goal of the experiment was to see under which conditions would photosynthesis occur best under. We used two bulbs of equal intensity and distance from the plant matter submerged in water, but one was red and the other was white, along with a control test of simply using the lights of the classroom. After 15 minutes of being under the light much more plant pieces had risen to the top of the glass (suggesting oxygen had been produced from photosynthesis) under the red light than both the white light and control group. Suggesting photosynthesis best occurs when under a red light

compared to a white one.
Introduction
Photosynthesis is arguably one of the most one of the most important processes on this planet.

Other than a small amount of organisms that convert underwater chemicals into energy, plants produce the overwhelming majority of consumable energy on this planet that allow for all other heterotrophs to exist.

Since plants lay dormant for their entire lives and lack any sort of hole to consume food, they need some sort of way to produce energy to survive and continue to grow. That is where photosynthesis comes in. During the process of photosynthesis, energy from the sun is taken in to the plant along with carbon dioxide and water in order to produce glucose (sugar energy) along with oxygen. This sugar will later be used by other parts of the cell in the process of cellular respiration to use up the energy that was made.

The process of photosynthesis takes place inside of the chloroplast. Inside the chloroplast sit many small disks called thylakoids in stacks called grannum. When sunlight hits these thylakoids “H2O are split (inside the thylakoid) into H+ions, O2 gas, the extra electrons, are added to the chlorophyll molecule to replace the ones it gave to the electron transport chain.” (Dr. Crabtree, 2018). Then the H+ molecules pass through a protein membrane that attaches a phosphate to ADP forming ATP (energy) while NADPH is made simultaneously. Following this the Calvin Cycle begins, in which CO2 molecules are used along with NADPH and ATP to make Glucose, thus ending the

process of photosynthesis.
Besides performing photosynthesis, there is one thing that many plants have in common. It is their color, many plants are, at least in some areas, a shade of green. This is because the chloroplast is green. The reason why chloroplast is green is because it is absorbing all colors of light, except green. If you look at a red shirt, the shirt absorbs all colors besides red, and reflects it off the shirt. That is why you see the color red. In the same manner, chloroplasts are green because they absorb all colors besides green. This was most likely done to maximize the amount of light energy plants could get from the sun.
What our project was most interested in was the color of the light and how the plant would best react to it.

We used 2 different light bulbs to test how photosynthesis works under different conditions, each 600 lumens in brightness and 10 centimeters from the top of the beaker the plant matter was sitting in. However, one lightbulb was red, and the other was a regular white lightbulb. Our independent variable was the color of light shone above the plant. Our dependent variable was the proportion of plant disks that floated to the top of the water after 15 minutes. Our hypothesis was that after 15 minutes, more disks would rise to the top of the water under the red light than under white light. Our reasoning for this was that white light is a combination of all colors of light, including green, so naturally some light would be reflected off the plant, but since the red light would not put out any green light, the plant would absorb all of the light and undergo photosynthesis much

faster.