Photosynthesis Investigation
This is the method used by plants to obtain their food. Plants which
use this process only are known as Autotrophic (self feeding)
organisms.
Plants produce carbohydrates as a result of Photosynthesis,
predominately glucose. If a plant cannot use the glucose immediately
it stores it in the form of starch. If the carbohydrates were stored
as glucose, this would have a drastic effect on each plant cell. They
would absorb water through osmosis, swell up and burst. Starch is
osmotically inert.
Photosynthesis takes place in special mini-organs (organelles in plant
cells called Chloroplasts). When chloroplasts are carrying out
photosynthesis they make temporary stores of starch in their cells, in
the form of grains. So the presence of starch grains in leaf tissue is
an indication that photosynthesis is occurring or has occurred very
recently.
How do we test a leaf to see whether starch is presence in leaf cells?
The iodine test for starch.
Method- step 1
· Half full a beaker with water and bring to the boil.
· Detach a leaf from a plant and place it into the water.
· Boil the leaf for two minutes.
· Remove the leave from the hot water; keep the hot water for next
step.
Step 2
· Place the leaf in a boiling tube, filled with ethanol.
· Put the boiling tube into the hot water kept from the last step.
· Swirl the leaf in the ethanol at least once.
· Continue with this programme until the leaf has turned pale yellow
and the ethanol has turned green.
Step 3
· Remove the boiling tube from the hot water.
· Carefully tip the ethanol away (into the beaker) and remove the
leaf.
· Drop the leaf back into the hot water, swirl it to remove any
ethanol, then place it carefully on a white tile.
· Spread the leaf out gently until it is flat.
Step 4
· Using a dropper, carefully add a few drops of iodine to the leaf
Cut a 5 cm length of celery stem 2. Cut through the grooves to divide the stem into thin strips 3. Dry the cell sap from the strips using a paper towel 4. Record and note the mass of each strip 5. Collect 6 test tubes, and put 10 cm³ of solutions 0.0, 0.1, 0.2, 0.3, 0.5, 0.7, 0.8.
An Analysis and Evaluation of Data from Photosynthesis Experiments Graph analysis This is my analysis for the investigation in to the affect of light intensity on the rate of photosynthesis to the Canadian pondweed, elodea. In the results the pattern is that when the light intensity is higher the readings are generally higher. On the graph the less the light intensity the lower the gradient of the curve. the equation for the photosynthesis process is; CO2 + 2H2O + Light Energy = =
To make the test fair I will use the same amount of water and the leaf
This will be done by adding different amounts of the nutrient into cups with duckweed and measure the growth of the duckweed. The cups shall contain 30 ml of water and be divided into 5 sets of three. The first set will not contain any trisodium phosphate, the second will contain 0.01 grams, then 0.1, then 1 and lastly 10 grams. 3 duckweed plants are added to each cup and then the plants are added, the number of leaves are counted. As the leaves are quite similar in size, this will serve as the measuring tool for the following measurements along with the number of
The results verified that the spinach had the highest chloroplasts concentration because it had the absorbency of 0.730, 0.826, 1.011, and 1.049 as shown in Table 1-4. The spinach was our positive control because, from a previous experiment, we knew that it would have chloroplasts; the buffer sucrose was the negative control because if the cabbage or lettuce did not have any contents of chloroplasts, then the readings should be equivalent to the buffer sucrose since it was our blank solution. Therefore, it should read 0.00, if there were no contents of chloroplasts. On the other hand, there was a flux in the data between the cabbage and the lettuce. However, the overall data suggested that the cabbage had a higher content of chloroplasts than
The purpose of this lab was to extract chlorophyll and carotenoid pigments from fresh spinach leaves and separate and analyze these pigments using column chromatography and thin layer chromatography. Acetone was used as a polar solvent to dissolve the more polar pigments first (Xanthophylls, chlorophylls), while hexane was used as a nonpolar solvent to dissolve the more nonpolar pigments such as the carotenes. In addition to being used as the polar solvent, acetone was used to remove the spinach components that were not pigments such as cellulose which is insoluble. The column chromatography worked by eluting the nonpolar carotene pigments first because the alumina is polar and doesn’t absorb the nonpolar carotene. The polar components such
Without carbon dioxide plants cannot photosynthesize. Through reading various books and web pages it was made clear that carbon dioxide is definitely one of the raw materials needed for photosynthesis, but I wanted to see whether this is actually true and if carbon dioxide is taken away completely will the plant photosynthesize at all? By taking a two plants of the exact same species, de-starching them both followed by putting plant one in conditions where carbon dioxide is taken away completely, and plant two will then be put in conditions where carbon dioxide is added, after a day or two in these conditions leaves from both plants will be tested for starch, if the leaf tests positive for starch it means that the plant has photosynthesized, if the leaf tests negatively for starch it means that the plant has not photosynthesized at all. The aim of my experiment is to see whether carbon dioxide is really necessary for photosynthesis, and to see if a plant can photosynthesize at all with no carbon dioxide present in its environment even when it is still exposed to all the other factors that are too needed for photosynthesis.
Orange (moderate), red orange (high). Seven tubes were tested that had 10 drops of a different liquid such as onion juice, potato juice, sucrose, glucose, distilled water, reducing sugar, and starch solution. In the Iodine starch test water, starch, milk, tofu, and apples was tested. The blue indicated that there was starch and yellow indicating there is no starch. In the biuret test for protein
* Count the number of bubbles seen in 1 minute which is a way of
The question we examined was how are photosynthesis and cellular respiration related? My hypothesis stated that if bromothymol blue, carbon dioxide, water and an Elodea plant are placed into test tube that is exposed to sunlight, then the bromothymol blue would change color which means that the plant has produced oxygen. When Bromothymol Blue is the color blue that indicates that oxygen is present. When Bromothymol Blue is the color green that signifies carbon dioxide is present. On Day 1, the Bromothymol Blue in all the test tubes was a orangish-yellowish-brown color. However, when we examined the Bromothymol Blue on day 2, in the control group, the color stayed same, a orangish-yellowish-brown. In the light test was bluish green and in the
to find effects of distance of a light source from pond weed has on the amount of oxygen
Photosynthesis, undoubtedly, is one of the most beneficial chemical reactions, for one simple fact. It keeps us alive. It is a simple, unassuming reaction, 6 CO2+ 6 H2O → C6H12O6+ 6 O2. So, it is just carbon dioxide and water reacting and turning into glucose and oxygen. “But,” you may ask, “Why is it so important?” It is because it takes our used air (CO2) and turns it back into the air we breathe (O2). Photosynthesis also turns our extra carbon dioxide into oxygen, reducing global warming's effects.
Plant photosynthesis happens in leaves and stems with green stem with a special organelle called a chloroplast. A plant leaf has tens of thousands of cells, and they contain 40-50 chloroplasts. The chloroplast, is an oval-shaped structure, and is divided by membranes into numerous disk-shaped compartments. The disk like compartments, which are called thylakoids, are placed vertically in the chloroplast and look like a stack of plates or pancakes. One stack of thylakoids is called a granum or more than one grana, the grana lie placed in a fluid known as the stroma. Inside of the thylakoids are hundreds of molecules of chlorophyll, which is a light capturing pigment used for photosynthesis. More light trapping pigments, like enzymes used to speed up chemical reactions, as well as other molecules used for photosynthesis and in the thylakoid membrane. These pigments
Introduction: What is photosynthesis, photosynthesis is the process where light energy is converted to chemical energy and stored in a chemical bond of sugar, all these reactions take place in structures called chloroplasts. During the process of photosynthesis, carbon dioxide, water, and light are consumed to produce glucose and oxygen. Thus bringing us to cellular respiration, this is where plants consume glucose and oxygen and produce carbon dioxide, water, and ATP energy molecules. To capture light energy for photosynthesis, chloroplasts absorb all light in the violet/blue and orange/red wavelengths. Almost all green/yellow light is reflected, which is why plants appear to be green.
...ed out very well as the plant I tested was correctly done, and it had a band that was yellow/brown where there was no starch present, the same leaf had a black boarder where the paper/foil was not placed, this was black because photosynthesis had occurred and produced starch. Therefore showing that light along with the other core ingredients are important factors for photosynthesis to take place successfully.