Photosynthesis Lab Report

Through this experiment, Egeria densa was observed using a microscope. The task was to observe and identify the different types of cell, cytoplasmic streaming, and plasmolysis of Egeria densa. First, the microscope was examined and investigated to master the use of the equipment. A microscope slide grid which was on the slide glass was required to be seen clearly using 4x, 10x and 30x. During the latter part of the experiment, the Egeria densa was observed using the microscope to understand the use of microscope by actually examining Egeria densa. The different types of cells of Egeria densa that were required to observe were the general cells, spinulose, a typical cell or idioblast, and base cell. Also, cytoplasmic streaming, and plasmolysis of the Egeria densa were observed and
sketched with different objective lens which was mastered when learning to use the microscope. The different cells, cytoplasmic streaming, and plasmolysis were observed. Each cell was sketched with different characteristics in appearance and location. Cytoplasmic streaming was the chloroplasts inside the cell moving in both clock wise and counter clock wise. The mechanism of the cytoplasmic streaming is the ATP powers little motor molecules called the myosin to move along actin filaments in the cytoskeleton. The myosin is attached to the actin filament on one end and the chloroplast on the other end. The purpose of the cytoplasmic streaming is to spread the products of the chloroplasts and aid in the chloroplast being exposed to light. Plasmolysis occurs when plant cell is placed in a hypertonic solution, causing the plant cell to shrivel and ultimately separate from its cell wall.

Purpose: In this experiment, mastering microscope and observing the cell and the processes such as cytoplasmic streaming and plasmolysis of Egeria densa with the knowledge acquired during the experiment of the usage of the microscope. Through the experiment, the use of the microscope can be understood by using several features such as different lenses and magnifications, and our observation skills are expanded by practicing making qualitative observations. Also, Egeria densa is learned more, not only the processes, but also about its different structures.

Procedure: Hold the neck of the microscope to take out the microscope from the box. Plug in the cord and turn the lens tube fixing knob to turn the eyepiece toward the experimenter. Turn the power on by turning the switch on the right bottom side of the microscope. Next to the switch there is an illumination knob to adjust the lightness and right above the knob, there is two black knobs hanging one after another which is to move the stage sideways (the top called knob controlling Y-axis of stage) and back and forward (the bottom called knob controlling X-axis of stage) to move the object that has to be observed. Behind the switch there is a big knob which is called the coarse adjustment knob and on top, there is the fine adjustment knob. The coarse adjustment knob moves the stage up and down. Be careful not to turn the coarse adjustment knob away from the experimenter, which means the stage will go up, so the objective lens and the stage may crash and damage the area. Therefore, when looking through the eyepiece, always turn the coarse adjustment knob toward the experimenter to lower the stage and look at the stage when turning the coarse adjustment knob away from the person when trying to raise the stage.

To change the degree of the objective lens (4x, 10x, 40x), turn the revolver which is a black dial to turn to the desired degree. (Never touch the silver part or the lens when switching) When the degree is changed, also change the iris diaphragm lever which is under the stage to the same degree and turn to the degree as the degree on the revolver in the middle. To place the slide glass, hold the stage clip and place the slide glass and place back the stage clip to set the slide glass. Place the slide glass that has the yellow sides that has the microscope slide grid to observe the image of the grid.

Focus the sample by using the Diopter ring by closing the other eye (if the left eye is used to focus, the right eye is looked into the eyepiece using the Diopter ring.
Also, adjust the eyepiece by pushing close or separating them to the appropriate position.
Perform the same process by changing the degree of the objective lens and focus to be able to see the grid clearly.

Using Egeria densa, cut a leaf using a scissor and place it onto the slide glass using a forcep and using the droppers drop some water and place coverslip on top of the leaf by sliding the coverslip when placing on top to prevent air which produces bubbles. Place the slide glass on the stage, by moving the stage clip and move the coarse adjustment knob toward the experimenter to set the stage to the lowest. Use the 4x or 10x objective lens, so move the revolver to that and also the iris diaphragm lever matched to the objective lens. Then, adjust the stage using the coarse adjustment knob, the knob controlling the x-axis, the knob controlling the y-axis, and the fine adjustment knob to focus. Observe and sketch the different cells (spinulose cell, atypical cell, general cell, base cell, and the
midrib)

Compare the front and back layers’ general cell size using the 40x objective lens. Provide an estimate in micrometer using the microscope slide grid.

Using a new leaf, place the leaf the same way on the slide glass and observe the cytoplasmic streaming using the 40x objective lens. (If cytoplasmic streaming was observed during the observation of cell, proceed with the observation of the plasmolysis with the leaf that was just changed)

Using a brand new leaf again, observe the plasmolysis by dropping 0.3 M NaCl solution instead of water using the dropper (different from the one used for water) and adjust the focus.

Results:
Using the microscope, the different types of cell of the leaves of Egeria densa can be observed.