Homework Assignment

The first part of the lab began by one lab member adding 10.0 mL of DI water to a test tube while another lab member obtained a beaker full of ice and salt. After both these steps were complete the test tube was put in the beaker full of ice. Immediately following the test tube be being placed in the beaker, a temperature probe was inserted into the test tube. The initial temperature was recorded and after the temperature was recorded in 30 second increments. Once the water exhibited supercooling and then remained consistent at .1 °C for 3 readings it was determined that the water had froze and formed crystals. Evidence that crystals formed allowed for it to be confirmed that the water actually hit freezing point at .0

The purpose of this experiment was to investigate the effects of light intensity on the rate of photosynthesis in a Moneywort plant. By observing the plant in distilled water mixed with sodium bicarbonate, different light bulbs were targeted onto the plant. The measurement of the amount of bubbles present on the plant during the trial of the experiment enabled us to identify the comparisons between the activity of the light and the process of photosynthesis.

This type of reaction is an oxidation-reduction (or redox) reaction. This reaction is also [anabolic/catabolic] and [endergonic/exergonic].

12. Describe two ways (two different things you could measure) to estimate the rate of photosynthesis in a particular plant. What specific measurements would you need to make for each in order to estimate GROSS photosynthesis?

6. Describe several adaptations that enable plants to reduce water loss from their leaves. Include both structural and physiological adaptations.

Introduction: Metabolism is a term in which defines all of the chemical reactions involving energy production. Some of these chemical reactions involve cellular respiration “by which is the series of metabolic process by which living cells produce energy through the oxidation of organic

Because chlorophyll-a takes in violet-blue, and orange-red lights to use in photosynthesis, it reflects green, and that is the color we see. This study investigates the relationship between the wavelength of light and the total respiration of the plant Elodea. The purpose is to see the effect of the presence or absence of certain wavelengths can have on the process of photosynthesis. Because Elodea is a plant that reflects green light, it can be assumed that red lights, the complimentary color to green will be absorbed the most contributing to the process of photosynthesis and respiration making the most oxygen.

The rate value of the spinach leaves that were not given light was negative. The negative change in the amount of oxygen can be explained by the fact that, in cellular respiration, one of the reactants is oxygen.

Elodea Canadensis, also referred to as American waterweed or common elodea, is an aquatic plant that is usually found in lakes, ponds or even rivers. Elodea helps support aquatic life such as young fish and amphibians by providing shelter and can be consumed as food by ducks and beavers. Elodea, like many other plants, relies upon photosynthesis to acquire its energy and to make food. To determine the importance of light energy in the process of photosynthesis, two Elodea plants were placed inside CO2 saturated water and exposed to different light intensities: one was under full light exposure while another was covered with mesh clothing to reduce the amount of light that it received; the solutions to this plants were then neutralized and compared to a control group which had no Elodea to see the amount of CO2 that each would have left after a period of an hour. The yielded results indicated that under high intensities of light, the Elodea plant photosynthesized and respired at the same rate; and while it was covered, it photosynthesized more because of an indicative decrease in CO2 levels. Therefore light energy is an essential aspect that affects the amount of CO2 that a plant can use in the process of photosynthesis.

Stomata closure is a coping strategy that plants use when there is low water available in the soil which prevents cavitation in the vessels of the xylem (Huber, 2015). It is also found that stomatal closure not only helps regulate transpiration in plants that have low water availability, but it also increases its water use efficiency (Huber, 2015). Wind is also considered to be a factor that affects transpiration in plants. Another study observed the effects of stomatal distribution (such as amphistomatous leaves) in leaves of a plant in low wind environments (Foster, 1986). The experiment found that amphistomatous leaves had the greatest transpiration rate at low wind speeds while hyperstomatous leaves had a higher transpiration rate than the hypostomatous leaves (Foster, 1986). Leaves contain what is called a boundary layer that can be defined as a still layer of fluid containing gasses and liquid that surround the leaf that affects the movement of CO2 and water in the leaves depending on its thickness (Bot 201L lab manual, 2016). In this study, the effects of wind will be observed on the transpiration rate and stomatal conductance in the leaves of

This experiment demonstrates the effects of pH on the rate of photosynthesis by examining the behavior of leaf disks in different pH solutions under light. In this experiment, we used five different pH levels: pH 5, pH 6, pH 7, pH 8 and pH 9. These solutions were created using a combination of hydrochloric acid and sodium hydroxide. Spinancia olcerea or spinach, leaves were used in the experiment to examine the effects of pH on the rate of photosynthesis. The rate of photosynthesis was measured by counting the number of leaf disks that rose to the surface of the solution after each minute. In acidic solutions, the rate of photosynthesis increased while in basic solutions, the rate of photosynthesis decreased.

The leaves of a plant are the main photosynthetic organs and are involved in gas exchange and water transportation throughout a plant (Evans et al, 17). A leaf typically consists of an upper and lower epidermis, the mesophyll cells, veins, guard cells and stomata. The mesophyll cells contains spongey cells which have large gaps between each cell to allow oxygen and carbon dioxide circulation. The mesophyll cells contain palisade cells, which are located beneath the upper epidermis. The palisade cells contain many chloroplasts, which are green organelles. Located in the internal layers of chloroplasts is the pigment chlorophyll which is involved in trapping the light energy in photosynthesis (Evans et al, 17).

Plant cells normally contain a large amount of water which is liable to freeze at low temperatures, with grave risk of damage to the protoplasm. Tropical plants are very easily killed by freezing, but it is evident that plants of temperate and arctic regions must have become adapted to survive the period of winter frost, meaning that they have developed cold resistance.

Metabolism is the word for every chemical reaction that takes place within a living organism. The energy is released from the food by respiration.

The surface of the leaf is uniformly coated with a water-resistant waxy cuticle that protects the leaf from excessive absorption of light and evaporation of water. The transparent, colourless epidermis layer allows light to pass through to the mesophyll cells where most of the photosynthesis takes place.