Photosynthesis is the process in which plants use the energy from the sunlight to make glucose, which is sugar. The plants then use the glucose as food. The equation for photosynthesis is: 6CO2 (Carbon dioxide) +6H2O (Water) –> (Sunlight) C6H12O6 (Glucose)+6O2 (Oxygen). Plants, algae, and cyanobacteria are photosynthetic beings Photosynthesis is the process by which phototrophs use water, carbon dioxide, chloroplasts, and light energy to make their own food. There are two smaller reactions that make up photosynthesis. These are the light independent reaction, and the light dependent reaction, or the Hill reaction. The reaction for photosynthesis is H¬2O + CO2 Essay on Photosynthesis Words2 Pages Photosynthesis is a biochemical process in which plant, algae, and some bacteria harness the energy of light to produce food. Nearly all living things depend on energy produced from photosynthesis for their nourishment, making it vital to life on Earth
Essays on Photosynthesis. Essay topics and examples of research paper about Photosynthesis
The leaves are the part of a plant where most photosynthesis takes place. If you cut a leaf in half and look at the cut end, it would look like this: Key: 1, photosynthesis essay. Waxy cuticle: this gives the leaf a waterproof layer, which lets in light.
Upper epidermis: provides an upper surface. Palisade cells: contain chloroplasts, photosynthesis essay. Spongy mesophyll: collection of damp, loosely packed cells. Lower epidermis: layer of cells on the lower surface. Air space inside the leaf: allows contact between air and moist cell surfaces. Stoma: a hole in the leaf through which gases diffuse. Guard cells: change shape to close the stoma.
One unique feature of leaves is that they have tiny holes in them to let carbon dioxide and oxygen enter and exit. The hole formed between these cells is called a stoma. A stoma is just a hole. It is controlled by two guard cells, which change shape to either open or close the hole, photosynthesis essay.
Something makes water enter the cells photosynthesis essay osmosis and so they swell up and change shape, but no one is quite sure of the trigger.
The stomata air holes on plants are normally open during the day and closed at night. These stomata are found on the undersides of leaves. This is because if they faced the sunlight, some of the plant's precious water could evaporate out of them.
This is the word equation: [IMAGE] Plants use the green dye or pigment called chlorophyll to pick up the energy from the sunlight. Plants make sugar and use some of it for energy to keep them alive respiration but they also use some for growth and repair by making fats and proteins. However, it is not always sunny so plants need to be able to store some of the sugar they make, so photosynthesis essay convert it to a storage carbohydrate starch. Plants could use starch or glucose.
Starch is insoluble it does not dissolve in water while glucose is soluble, photosynthesis essay. This means that if starch is used, less water is required to keep its food stored. The amounts of water, carbon dioxide, sunlight and temperature can all affect how effectively a photosynthesis essay carries out photosynthesis. Hire a subject expert to help you with Photosynthesis. The amount of water is effected by how much is taken up through the roots and how much is lost from the leaves.
If less water is available in the leaf then photosynthesis will occur more slowly, photosynthesis essay. Similarly, if there is less carbon dioxide around then photosynthesis will occur more slowly. There wont be enough of the fuel substrate to get the reaction to work. If there is less sun, photosynthesis essay, which usually means it is cooler too, then there is less energy for photosynthesis and it occurs more slowly.
So photosynthesis works best when it is warm and sunny. To do this, I am going to observe Canadian pond weed Elodea photosynthesis essay varying light intensities, photosynthesis essay. The Elodea will photosynthesis essay submerged in water. I will count the amount of oxygen given off in this experiment by counting the number of bubbles produced, photosynthesis essay. I used Canadian pondweed because of its unusual ability to emit photosynthesis essay of gas from a cut end, when placed in water.
Photosynthesis occurs only in the presence of light, photosynthesis essay, and takes place in the chloroplasts of green plant cells. Photosynthesis can be defined as the production of simple sugars from carbon dioxide and water causing the release of sugar and oxygen. This has been proven many times in experiments, so it is possible to say that without light, the plant would die.
The reason that light intensity does affect the rate of photosynthesis is because as light and therefore energy falls on the chloroplasts in a leaf, it is trapped by the chlorophyll, which then makes the energy available for chemical reactions in the plant. As the amount of sunlight or in this case light from a bulb falls on the plant, energy is absorbed.
This means that energy is available for the chemical reactions, and so photosynthesis essay takes place. The more light there is that falls on the leaf in the first place, the quicker the rate that the reaction can take place.
There are many factors which will affect the rate of photosynthesis, including light photosynthesis essay, temperature and carbon dioxide concentration. The maximum rate of photosynthesis will be controlled by a limiting factor.
This factor will prevent the rate of photosynthesis from rising above a certain level, even if the other conditions needed for photosynthesis are improved.
It will therefore be necessary to control these factors throughout the experiment so as not to let them affect the reliability of my investigation into the effect of light intensity.
Predictions I predict that as the intensity of light increase, so will the rate of photosynthesis. I also predict that if the light intensity increases, the rate of photosynthesis will increase at a proportional rate until a certain level is reached, and the rate of increase will then go down. Eventually, a level will be reached where an increase in light intensity photosynthesis essay have no further effect on the rate of photosynthesis, as there will be another limiting factor, in this case probably temperature.
To alter the light intensity, I placed a lamp at various distances from the plant. I also therefore needed a way of accurately measuring the light intensity, and I did this using a light intensity monitor.
I obtained the following results:, photosynthesis essay. This lack of accuracy was mainly due to the fact that by simply counting the bubbles, I was relying on each bubble being exactly the same size, which they clearly were not. The preliminary experiment will give me a best fit curve to which I can compare my main graph, and also points at either end of my results at which it is clear to see light intensity has little or no effect.
In my main experiment, it will not be necessary to take readings above this point. Here are my results from my preliminary experiment: [IMAGE] Method Input variables Light intensity - This is to be varied by increasing and decreasing the distance from the light source to the plant Output variables Volume of oxygen rate of photosynthesis - This is to be measured by finding the photosynthesis essay of bubbles of oxygen produced in a 30 seconds.
Carbon dioxide concentration - This can affect the rate of photosynthesis, since if there is too little CO2, it can become the limiting factor. In this case, as long as the experiment is done over a short period of time, the amount of carbon dioxide used up by the photosynthesis essay will not be sufficient enough to cause the carbon dioxide concentration to become the limiting factor. If my experiment were to be performed over a longer period of time, this would become a problem.
Water availability - Water is also required in the photosynthesis reaction, and when it is lacking, the plants' stomata close to prevent further water loss. This closing of the stomata cells also leads to little carbon dioxide being able to diffuse through. Clearly, in a water photosynthesis essay, like the pondweed as long as the plant is fully submerged in water at all times, this will not be a problem. Temperature - Enzymes are used in the photosynthesis reactions of a plant.
Therefore, photosynthesis essay, temperature will increase the rate of photosynthesis, until a point at which the enzymes weaken and work at a slower rate. I am going to perform the experiment at 22 degrees, checking the temperature frequently in case the heat given off from the light should slightly raise the temperature, in which case I shall simply refill the beaker with more water after each experiment.
Apparatus list A§ Desk photosynthesis essay A§ Elodea pondweed A§ Clamp A§ Water A§ Thermometer A§ Test-tube A§ Beaker A§ Cold water A§ Stopwatch A§ Light intensity meter Cut a stem of Canadian pondweed of about 7cm in length, photosynthesis essay. Fill a test-tube with water, photosynthesis essay, and place it in a clamp. Then place the test tube into a beaker of cold water. Insert a thermometer into the beaker, and record the temperature at the beginning and end of each experiment, as a precaution against a significant unexpected rise in temperature.
Set up a lamp at a set distance from the plant, ensuring that this distance is from the filament of the lamp to the actual pondweed, rather than the edge of the beaker. The light intensity must be measured in the same way as described in the preliminary experiment. When bubbles are being produced at a steady rate, start the stopwatch and count how many oxygen photosynthesis essay are produced in 30 seconds.
Repeat this experiment three times for accuracy, photosynthesis essay. The results are rounded up to integers because the "number of bubbles counted" is discrete data ie - "4 and a half bubbles" would not be appropriate.
I drew it as a curve rather than a straight line because of the clear pattern of the points. This meant that the rate of photosynthesis increased as the light intensity increased, photosynthesis essay.
This was because photosynthesis is a photosynthesis essay, which needs photosynthesis essay from light to work, photosynthesis essay, so as the amount of energy available from light increased with the rise in light intensity, so did the amount of oxygen produced as a product of photosynthesis. My graphs showed that the relationship between the light intensity and the rate of photosynthesis was non-linear, as both graphs produced a best-fit curve.
However, as I expected in my hypothesis, it does appear that for the very first part of the graph, the increase in rate is in fact proportional to the increase in light intensity i. The gradual decrease in the rate photosynthesis essay increase of the rate of photosynthesis the shallowing of the curve can be attributed to the other factors limiting the rate of photosynthesis.
As light intensity increases, the photosynthetic rate is being limited by certain factors, such as carbon dioxide and temperature. These factors do not immediately limit the rate of photosynthesis, but rather gradually, photosynthesis essay.
As light intensity increases further, so the rate of photosynthesis is being limited by other factors more and more, until the rate of photosynthesis is constant, and so is almost certainly limited in full by another factor.
Overall, both graphs and my results support my predictions fully. My idea that the rate of photosynthesis would increase with light intensity was comprehensively backed up by my results, photosynthesis essay. This is because a higher light intensity involves photosynthesis essay greater level of light energy, which can then be transferred to a special protein environment designed to convert the energy, photosynthesis essay.
Here, the energy of a photon is used to transfer electrons from one chlorophyll pigment to the next. When enough energy has been gathered at a reaction centre, ATP can be synthesised from ADP. The oxygen collected in the experiment is in fact the by-product of this reaction, and so it is lear to see that the more light energy, photosynthesis essay, the more ADP is being converted into ATP and more oxygen is produced as a result.
As I have already stated, my preliminary experiment was not accurate enough to justify being used as my main experiment, photosynthesis essay. This was mostly due to the fact that I was relying on all the bubbles being the same size, photosynthesis essay, which they clearly weren't, however many of the smaller inaccuracies also apply to my main experiment.
Firstly, the distance between the light sources and the Canadian Pondweed were not measured to a very high degree of accuracy, photosynthesis essay, especially when you note the fact that the distance should have been measured exactly from the filament of the light bulb to the centre of the plant. It is possible here to find a percentage error. I estimate that the error could have been up to 0. Although I was not actually using the distances as part of my results, photosynthesis essay, I used them as a marker for where the lamp was placed each time, as I assumed that the light intensity would be the same each time at a particular distance.
Therefore, any inaccuracies in measuring the distances, i. f a distance was slightly different when doing the actual experiment from the distance at which I earlier measured the light intensity, an error would ensue. The second major inaccuracy was in measuring the volume of oxygen given off.
Photosynthesis \u0026 Respiration - Reactions - Chemistry - FuseSchool
, time: 6:11Photosynthesis Essay Examples | Sample Essays
An overview of photosynthesis Introduction. Photosynthesis is the ultimate source of all of humankind's food and oxygen, whereas fossilized The site of photosynthesis in plants. In land plants, the principal organs of photosynthesis are the leaves (Figure 2 Photosynthetic electron and proton Essay on Photosynthesis Words2 Pages Photosynthesis is a biochemical process in which plant, algae, and some bacteria harness the energy of light to produce food. Nearly all living things depend on energy produced from photosynthesis for their nourishment, making it vital to life on Earth · The chemical equation for photosynthesis can be expressed as: sunlight [IMAGE]Carbon dioxide + water sugar (glucose) + oxygen + water CO2 + H2O C6H2O6 + O2 + H2O All plants need light in order to photosynthesise. This has been proven many times in experiments, so it is possible to say that without light, the plant would blogger.comted Reading Time: 9 mins
No comments:
Post a Comment