Photosynthesis Hypothesis

Purpose: The purpose of this experiment is to see how long it takes for the 10 spinach leaf discs to undergo photosynthesis and thereby rise in the two solutions. Hypothesis: All of the leaf discs in the sodium bicarbonate solution should be floating before the discs in plain water because the bicarbonate is a carbon source that will allow photosynthesis to continue. Background: Light is absorbed by leaf pigments (chlorophyll) which makes electrons within a photosystem moved to a higher energy level. The leaves then make ATP, which reduces NADP to NADPH, and add CO2 into organic molecules. When the leaves go through the process of a light-dependent reaction by being placed in water, oxygen is created through photosynthesis and is released into the interior of the leaf.

The faster the bubble moves, the greater the rate of transpiration. I will be placing one plant in an environment where it is exposed to high-light intensities, and another plant in an environment where it is exposed to low-light intensities. Transpiration is the process of the transport of water and nutrients up the the plant from the roots to the leaves. The water moves up the roots against gravity through the dead xylem cells without the assistance of a pump. Water is absorbed by the plant through the roots through the process of osmosis, which then exits the plant through the openings of the leaves, known as the stomata.

The hypothesis proposed that if the leaf disks were put in solutions that are at different temperatures, then the leaf disks in the warmest solution would produce oxygen the fastest. The data revealed that there is great support for this hypothesis. The data showed that the solution with all ten of the leaf disks floating in the least amount of time was the 38°C solution which was the warmest. In contrast the solution that had the least amount of leaf disks, about seven and a half leaf disks, was the 7°C solution which was the coolest. The control solution had the second most leaf disks, on average, floating at 20 minutes.

In photosynthesis, carbon dioxide and water are used to produce glucose and the by-product oxygen, and there is an intake of energy. In respiration, on the other hand, glucose and oxygen are broken down into carbon dioxide and water, and there is a release of energy. Basically, the products of one serve as the reactants of the other, and vice versa. As the name suggests, light-independent reactions do not need the presence of light to function. The process occurs in the stroma and it produces G3P, which is used for carbohydrates such as glucose.

The graph shows the average volume of hydrogen that was produced from the 3 trials and the average volume of oxygen that was produced from the 3 trials across the voltage. I added the volumes of hydrogen in each trial and I divided them by 3 to get the average and I made the same thing for the volume of oxygen. The graph shows that the volume of hydrogen produced during the experiment is twice as much as the volume of oxygen. For example using the third data when I used 11 volts the average volume of hydrogen that was produced was 5.8 cm3 and the average volume of oxygen produced was 2.9 cm3 so when you multiply the 2.9 by 2 it gives you 5.8 cm3 which was my result. As the voltage increases the volume of hydrogen and oxygen increases.

Despite its name, bromothymol blue solution may sometimes appear yellow or reddish depending on the pH of the stock water used to prepare this pH indicator solution.Low levels of carbon dioxide or acid in solution with bromothymol blue indicator will appear blue. As the level of carbon dioxide or acid increases, the solution will gradually take on a yellow tint. This makes bromothymol blue ideal for biology experiments to indicate photosynthetic activity (solution turns blue as plants use up carbon dioxide) or respiratory activity (solution turns yellow as carbon dioxide content increases).Carbon dioxide is a byproduct of cellular respiration. Therefore, we can measure the amount of carbon dioxide as an indicator of cellular respiration. When carbon dioxide combines with water it forms carbonic acid.

Germinating peas and maize respire at faster rates than fresh and dried peas and maize at room temperature and 400C(graph no). This could be because pea seeds have two cotyledons as compared to the single one of maize so oxygen usage is also more. These results support my hypothesis stated earlier. Respiration is an enzymatic process where enzymes are required at every step in the breakdown of glucose. At 600C for both peas and maize the respiration rate went down as the enzymes denatured.

Task 1 When you exhale onto a window it steams up because your breath contains water vapour and it causes water vapour to condense forming small water droplets. We breathe in oxygen and some nitrogen which is essential for life. We exhale carbon dioxide that can be tested for limewater because carbon dioxide dissolves in water to form carbonic acid (H2 C03). Glucose is a reactant of respiration. The glucose in your blood comes from carbohydrates in your food.

Next, we timed the oscillation of a 100 g weight hooked onto a 29 cm string. After ten trials we found the average time period for the 100g weight to be 1.24 seconds. Then we tested the 50g weight and found the average period to be 1.17 seconds. As you can see, even though we changed the mass, the period of time it

Nitrogen would have a key role in eutrophication and would help people understand how to stop eutrophication and control it too. If nitrogen does increase the growth of plants then that means it speeds up or makes the chance that eutrophication will occur go up more. Even then, nitrogen may not be and probably is not the only factor affecting plant growth and eutrophication but will contribute to the understanding of both of them. With this knowledge people could find the main source of nitrogen in the environment that humans are imputing in to the environment. This will lead to taking better care of the environment and its ecosystems while minimizing the effects humans have on it by decreasing the eutrophication