Photosynthesis. Photosynthesis consists of two stages. A series of light-dependent reactions that are temperature independent and a series of temperature-dependent reactions that are light independent
Research: Photosynthesis is the process by which chlorophyll containing organisms (green plants, algae, and some bacteria) capture energy in the form of light and convert it to chemical energy. Virtually all the energy available for life in the earth's biosphere (the zone in which life can exist) is made available through photosynthesis. A quite general, unbalanced chemical equation for photosynthesis is CO2 + 2H2A + light energy ? CH2 + H2O + H2A The formula H2A represents a compound that can be oxidized, which means, electrons can be removed. CO2 is carbon dioxide and CH2 is the hydrocarbons incorporated by the growing organism. In the vast majority of photosynthetic organisms such as, algae and green plants, H2A is water (H2O) but in some photosynthetic bacteria H2A is hydrogen sulfide (H2S). Photosynthesis involving water is the most important and best understood by scientists today. I have explained it in detail below. Photosynthesis consists of two stages. A series of light-dependent reactions that are temperature independent and a series of temperature-dependent reactions that are light independent. The rate of the first series, called the light reaction, can be increased by increasing light intensity (within certain limits) but not by increasing temperature. In the second series, called the dark reaction, the rate can be increased by increasing temperature
Photosynthesis and Light intensity
PLANNING A Aim: The aim of this experiment is to investigate the effect of different light intensities on the rate of photosynthesis Theory & Hypothesis: The photosynthesis rate is often measured by the amount of carbon dioxide absorbed or oxygen evolved by a plant. With increase in light intensity, photosynthesis begins, and some carbon dioxide from respiration is utilized in photosynthesis. As light intensity increases, there is an increase in the rate of photosynthesis, and this light intensity can be increased or decreased by bringing the source of light closer to or further away from the plant. Hypothesis: Hence, we can predict that with increase in light intensity, the rate of photosynthesis would also increase. Variables: The variables in the experiment are light intensity and the rate of photosynthesis. The independent variable is light intensity, which is adjusted by modifying the position of the lamp. The dependent variable is the rate of photosynthesis or the rate of bubble production which is affected by the varying light intensity. PLANNING B Apparatus & Materials: . Water plant (Hydrilla) 2. dil.sodium hydrogen carbonate solution 3. Thermometer 4. Boiling test-tube 5. Beaker 500 ml 6. Retort stand 7. Lamp (60W bulb) 8. Ruler 9. Stop-watch Procedure: . Place the hydrilla in a test-tube filled with dilute sodium hydrogen carbonate solution 2.
The Light Dependent Reactions of Photosynthesis
Overview Living things require energy to stay alive. The main energy source for autotrophs, a group of organisms that produce their own food, achieve this by gathering natural commodities such as water and sunlight. These sources of energy are converted through a series of biochemical l processes into substances that the autotroph can use to maintain its necessary functions. The sun is the starting point for the process of photosynthesis ("photo" refers to light sunlight). The sun emits many, many different wavelengths, including X-rays, UV rays, and a spectrum of light that is visible to us. The light used by photosynthesis is the spectra of visible light. The figure above shows the spectra of light which is absorbed by a plant. The sun is sometimes thought to emit simply a white light, but sunlight is actually reflected in a spectra similar to the one shown above. Plants appear to have a green color because this green light is not absorbed as much as other colors (with different wavelengths). As a result, this light is reflected by the plant, showing its green color. Another feature of the above graph is the inclusion of several pigments in the typical autotroph. Organisms that undergo photosynthesis contain a variety of colored pigments, which are organized on membranes within chloroplasts. These pigments include Chlorophyll a, Chlorophyll b, and various carotenoids.
How does light intensity affect photosynthesis?
Introduction Photosynthesis is a very important process in nature. Photosynthesis is a biochemical reaction used to produce glucose using light energy, water and CO2 (Carbon Dioxide). A bye product of the reaction, photosynthesis, is Oxygen. It takes place in all green plants, which use the green chlorophyll, held in chloroplasts in the leaves, to trap light. The main site of photosynthesis is the palisade mesophyll cells in the leaf of a plant. It is these cells that contain the green chloroplasts and are very well adapted to do their task. They are near the upper side of the leaf where they can obtain the maximum amount of light, they are packed very closely together and as already mentioned contain green chloroplasts clustered towards the upper side too. Plants photosynthesise to produce food chemicals that are needed to allow them to grow. The main reaction is to produce oxygen and glucose to be changed into energy during respiration. Glucose is stored in the form of starch which is insoluble and does not affect the osmosis taking pace in the plant. As plants respire both day and night this starch is often used up during the night when photosynthesis cannot take place. The uses of glucose within the plant are for active transpiration, cell division, the production of protein and the production of cellulose. Light energy is used to break down the bonds in water and
Light Intensity and Photosynthesis.
Light Intensity and Photosynthesis Biology Coursework Aim The aim of my experiment was to determine whether or not the intensity of light would affect the rate of photosynthesis in a plant. To do this, I placed a piece of Canadian pondweed in varying light intensities, and observed the amount of oxygen being given off. I used Canadian pondweed because of its unusual quality of giving off bubbles of gas from a cut end, when placed in water. Introduction Photosynthesis occurs only in the presence of light, 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. The chemical equation for photosynthesis can be expressed as: (light) 6CO2 + 6H2O À C6H12O6 + 6O2 (in the presence of chlorophyll) The fact that all plants need light in order to photosynthesise has been proven many times in experiments, and 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. Thus, as the amount of sunlight, or in this case light from a bulb, falls on the plant, more energy is absorbed, so
Investigation into the colour of light needed to start a photosynthesis reaction
Investigation into the colour of light needed to start a photosynthesis reaction Diagrams Method The apparatus for this experiment will be setup as shown in the diagram, for all the experiments the coloured filter will be 5cm away from the white light bulb, which is a 60watt bulb, and the beaker will be 20cm away from the edge of the coloured filter. Just before the experiment takes place we will place the pond weed (which has been in darkness for at least 24 hours to stop it any photosynthesis) into the beaker. I will then place the funnel over the pond weed and place the test-tube into the beaker (like the diagram above) I will then fill the beaker up with cold tap water till it covers the bottom of the test tube (450ml). This is so that we can easily count the oxygen bubbles as they come off the pond weed. Now that the experiment is ready to start, I will turn on the light for one minute, then after the first minute I will count how many oxygen bubbles come from the pond weed in the second minute. I will repeat this stage again once 10 minutes has passed. The preliminary experiment was done to check my prediction of what I think will happen. For this I used red, green and blue filters. The main experiment will be done with more colours if it proves successful - I will repeat the experiment with more colours: red, orange, green, blue and purple filters. I will take three
How light intensity affects Photosynthesis.
P l a n Photosynthesis is the chemical process, which takes place in every green plant to produce food in the form of glucose. Plants use water and carbon molecules and the suns energy to join together to form glucose, which is sent around the plant to provide food. Cells in the root or stem can use the glucose to make energy, if the plant does not need to use all the glucose immediately then it is stored which is difficult because glucose is hard to store in water. Plants have adapted with this problem by joining hundreds of glucose molecules together to make a starch compound. Starch does not dissolve in water very well so it makes a better food store. Photosynthesis takes the palisade mesophyll cells in the leaf of a plant. It is these cells that contain the green chloroplasts and are very well adapted to their task. They are near the upper side of the leaf where they can obtain the maximum amount of light, they are packed very closely together and contain a green pigment called chlorophyll, and these absorb the sunlight and therefore help greatly to the production of photosynthesis. The cells are arranged like a fence, these help the energy entering the surface (top) of the leaf to travel a long way through the palisade cells. To obtain the most sunlight as possible, leaves have a large surface area and the more sunlight the plant receives, the better it can
How Light Affects Photosynthesis.
Title: How Light Affects Photosynthesis. Aim: My aim was to investigate how light affected photosynthesis. Prediction: My prediction is that the closer the weed is to the light the faster the photosynthesis as light acts as a catalyst which speeds it up. Bibliography: For my work I used the internet and certain science books for info. Hypothesis: Photosynthesis is a process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. In doing so, photosynthesis provides the basic energy source for virtually all organisms. An extremely important by product of photosynthesis is oxygen, on which most organisms depend. Factors that affect Photosynthesis * Light affects the rate of photosynthesis, it is the main energy source, and this is what we are testing in this investigation. * Carbon Dioxide is a raw material which affects the rate of photosynthesis * Water also affects the rate of photosynthesis; this water mostly comes from the roots. * Chlorophyll is the miracle molecule which actually makes photosynthesis The word equation for photosynthesis is: Carbon Dioxide + Water Light Glucose + Oxygen 6CO2 + 6H2O Chlorophyll C6H12O6 + 6O2 + Energy Things needed for Photosynthesis * Light * Carbon Dioxide * The right
How does light intensity affect the rate of photosynthesis?
How does light intensity affect the rate of photosynthesis? Poorly Pondweed Questions ) How does light intensity affect the rate of photosynthesis? 2) How does temperature affect the rate of photosynthesis? sunlight carbon dioxide + water àààààà glucose + oxygen chlorophyll sunlight 6CO2 + 6H2O àààààà C6H12O6 + 602 chlorophyll Prediction I predict that the more intense the light, the higher the rate of photosynthesis. To photosynthesise, plants need light. It provides the energy for the process to happen. Chlorophyll is an enzyme and it speeds up the reaction. If a plant does not get enough of either of these things, photosynthesis will not happen as quickly, if at all. Therefore, I predict that when the light is not very intense we will not see so many bubbles being produced. This is because the plant will not have so much energy (derived from light) to activate photosynthesis. All reactions require a certain activation energy, and if this is not reached the reaction will occur more slowly. I think that as we move the lamp away (and therefore reduce the light intensity) from the elodea pondweed the number of bubbles produced will decrease steadily. For instance, say at 10cm distance 50 bubbles are counted, it is likely that at 20cm distance 25 bubbles will be counted, as the lamp is twice the distance away. This means the rate of photosynthesis is
How does light intensity affect the rate of photosynthesis?
Emma Lazarus 10Y1 10/PLR Poorly Pondweed Questions ) How does light intensity affect the rate of photosynthesis? 2) How does temperature affect the rate of photosynthesis? sunlight carbon dioxide + water -->-->-->-->-->--> glucose + oxygen chlorophyll sunlight 6CO2 + 6H2O -->-->-->-->-->--> C6H12O6 + 602 chlorophyll Prediction I predict that the more intense the light, the higher the rate of photosynthesis. To photosynthesise, plants need light. It provides the energy for the process to happen. Chlorophyll is an enzyme and it speeds up the reaction. If a plant does not get enough of either of these things, photosynthesis will not happen as quickly, if at all. Therefore, I predict that when the light is not very intense we will not see so many bubbles being produced. This is because the plant will not have so much energy (derived from light) to activate photosynthesis. All reactions require a certain activation energy, and if this is not reached the reaction will occur more slowly. I think that as we move the lamp away (and therefore reduce the light intensity) from the elodea pondweed the number of bubbles produced will decrease steadily. For instance, say at 10cm distance 50 bubbles are counted, it is likely that at 20cm distance 25 bubbles will be counted, as the lamp is twice the distance away. This means the rate of
