An experiment to determine how different colors of light affect the photosynthetic rate of spinach l

Ideally, a teacher would have no more than twenty four students to coach through this activity. A student will have prior knowledge as to the equation describing the photosynthetic process as well as having a basic understanding of the scientific method. The lab could be used in a unit on, the scientific method, a photosynthetic unit or in a unit on environmental problems global climate change and its affect on plants.

An experiment to determine how different colors of light affect the photosynthetic rate of spinach l

Rate of photosynthesis was determined at pH 7, 0. The amount of oxygen production was determined after five minutes at each light intensity. Spinach leaf segments were infiltrated with 0. The rate of oxygen production increased relatively rapidly at lower light intensities but leveled off at intensities greater than lux, suggesting that light intensity is a limiting factor of photosynthesis below lux.

At light intensities greater thenhowever, light intensity is no longer limiting. Instead other factors such as amount of water, NaHCO3, chlorophyll, and other reagents of photosynthesis become limiting. Photosynthesis is a process that underlies all life on Earth. It is essential in creating the sugars that sustain life.

By converting light energy into chemical energy in the form of carbohydrates, it not only sustains the life of photosynthetic organisms themselves called Sorry, but full essay samples are available only for registered users autotrophsbut also provides food for the heterotrophs that consume autotrophs.

Overall, photosynthesis consists of two sets of reactions: In the light dependent reactions use energy from light is absorbed by chlorophyll. This powers the release of electrons from water, which are then transferred to the electron carrier, NADPH.

Oxygen is a product of the light dependent reactions. In contrast, the light-independent reactions result in the production of sugar from carbon dioxide.

It is useful to study factors that affect rate of photosynthesis in order to determine the conditions of optimal photosynthetic activity and explain various characteristics of plants.

For example, understanding the affect of light intensity on rate of photosynthesis may reveal why shrubs in the shade do not grow as tall as trees with greater exposure to sunlight. In this experiment, spinach leaves were subjected to varying light intensities to determine the effect of light intensity on rate of photosynthesis as measured by production of oxygen.

We expected rate of photosynthesis to increase with increasing light intensity. This was because increasing light intensity would increase the amount of energy available for the light dependent photosynthetic reactions.

However, the increasing rate of photosynthesis was predicted to eventually level off with increasing light intensity because when light intensity was no longer a limiting factor of photosynthetic rate, other factors such as amount of water and CO2 became limiting.

This investigation involved determining the effect of light intensity on the rate of photosynthesis as measured by rate of oxygen production of spinach leaves. This measurement was taken by the determining the rate at which spinach segments floated in liquid as oxygen produced during photosynthesis diffused into liquid-filled intercellular spaces.


However, intercellular spaces of spinach leaves are largely gas-filled by nature. Thus, the spinach segments were first made to sink by subjecting a mixture of the leaves and 0.

An experiment to determine how different colors of light affect the photosynthetic rate of spinach l

The rate of leaf segments found floating parallel to the surface of the liquid not tilted was recorded as a measure of rate of photosynthesis. Incandescent light bulbs provided the light source for leaf segments to undergo photosynthesis.

The leaves were submerged in solutions of NaHCO3 which were placed under the lamps. In addition, clear vessels of water were positioned between the lamps and leaf mixtures as heat sinks to prevent the leaves from denaturing from the heat of the lamps.

The volume of water and size of the vessels used for these heat sinks were the same for each treatment to control temperature. The concentration of NaHCO3 was also held constant at 0. Wavelength of light was uniform at white. All treatments were tested at room temperature.

Size of leaf segments and number of leaf segments were also consistent for each treatment. To determine the effect of light intensity on rate of photosynthesis, the leaf mixtures were subjected to intensities of, and lux.

A treatment was performed in the dark 0 lux for the control. Leaf segments observed floating at 0 lux would indicate oxygen production from spontaneous reactions other than photosynthesis.

This would have been subtracted from the rates of photosynthesis of the other treatments to make the correction. The rate of oxygen production as measured by percent of floating leaf segments after five minutes was graphed against light intensity.The intensity of light directly affects the rate of photosynthesis (Bidwell, ).

Graphs show that the higher the intensity, the higher rate of photosynthesis. The intensity in this experiment was increased by moving the tube closer to the light.

The Effect of Light Intensity and Temperature on the Rate of Photosynthesis Aim The aim of my experiment is to determine whether intensity of light and temperature would affect the rate of photosynthesis in a plant. Students conducted an experiment to determine the effect of light intensity on the rate of photosynthesis.

They punched 40 leaf disks from spinach leaves and used a syringe partially filled with water to pull the gases from the leaf disks so that all leaf disks sunk to the bottom of the syringe. There are 4 matters that affect on the rate of photosynthesis, light intensity,temperature, CO2, water and the color of light in general.

In this lab, the color of light isinvestigated. Since the photosynthesis takes place in chloroplast that has chlorophyll, the rateof photosynthesis is affected by the color of light as the amounts of light.

In this lab experiment, the team examines how the rate of photosynthesis is affected by different light colors in the leafs. Five different variables were tested; green light, red light, yellow light, blue light, and regular white light at a controlled distance of approximately 10cm.

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