EXERCISE 11Transfer of Water and Materials In and Out of the Plant

INTRODUCTIONThe maintenance of a steady living state is very vital for every living organism. Thus, this equilibrium is achieved through the regulation of the transport of specific substances to particular sites, moving molecules in and out of the cells through membranes, either permeable or semi-permeable. This activity of the cell is involved in cellular activities like growth, absorption and respiration. Transport can also be either passive or active depending on the energy requirement of the process. Diffusion is a kind of passive transport wherein dissolved molecules move from higher to lower concentration.

HYPOTHESISConcentration of the solvent, size of the dissolving particle and temperature affects the rate of transport through membranes.OBJECTIVES1. To determine some factors that affect the diffusion process.2. To differentiate diffusion from imbibition.3. To determine some factors that affect the permeability of cell membranes.4. To demonstrate the various processes by which materials are transported and transpired.

RESULTS Diffusion of Selected Plant Pigments Test tube 1 contains 1g atsuete seeds and 10 ml distilled water Test tube 2 contains 1g atsuete seeds and 10 ml distilled water and place in boiling water bath Test tube 3 contains 1g atsuete seeds and 10 ml vegetable oil Test tube 4 contains 1g atsuete seeds and 10 ml heated vegetable oil

SUBSTANCEOBSERVATION ( COLOR INTENSITY)

Test tube 1 +

Test tube 2+++

Test tube 3++

Test tube 4++++

Osmosis

TURGID CELL OF BOAT OF MOSES PLASMOLYZED CELL (5% salt solution)

Factors affecting the integrity of Cell Membranes

Sugar beets slices placed on different chemicals and conditions.TEST TUBEINTENSITY COLORTEST TUBEINTENSITY OF COLORTEST TUBEINTENSITY COLOR

A (room temp)

+++D (chloroform)+++F (NaOH)+++

B (refrigerator)++E (acetone)++++G (HCl)++++

C (60 oC)+

Blue = effect of temperatureBrown= effect of organic solventsPink= effect of pH

Imbibition

MediumImbibantInitial Weight (g)Final weight% in Weight

Waterrubber

0.6 0.6 0%

wood2.63.742.31 %

seeds1010.11 %

Kerosenerubber0.60.950 %

wood0.81.250 %

seeds1010.11 %

Movement of water through the stem

Pechay leaves immersed in 10 ml of 0.01% of eosin dye solution.

Traces of eosin dye solution

Comparison of the Cuticular and Stomatal Transpiration

Leaf A no petroleum jelly applied.Leaf B had petroleum jelly applied on the upper surface.Leaf C had petroleum jelly on the lower surface.Leaf D had petroleum jelly on both surface.

RESULTS: (decreasing order of dryness)LEAF A > B > C > D

Guttation

Droplets were formed on the leaf margin.

DISCUSSIONS Diffusion of Selected Plant Pigments The rate of diffusion is affected by the rate of the concentration gradient of the solvent and temperature. Color intensity shows the rate of the process. In the experiment, wherein Test tubes C and D contained 1 g atsuete seeds and vegetable oil, the diffusion was faster compared to the other test tubes containing water as a solvent. This is because the greater the gap between the concentration gradients in the seed and the solvent, the faster the rate of diffusion. Test tube A containing atsuete seeds in water turned out to have the slowest rate because water is less concentrated than vegetable oil. Observing also the difference between the test tubes to which heat was applied. Test tube B, boiled, turned out to have a faster rate of diffusion than A and the same with D compared to C. This is because the higher the temperature, the faster the rate of the process. Another factor was the size of the dissolving material, though it was not emphasized in the experiment, the bigger the size of the solute, the slower the rate of diffusion.Carotene, the pigment escaping from the seeds, travelled the farthest because it is the most soluble among the pigments.

Osmosis

In a turgid cell of Boat of Moses, the direction of water was inward which causes the swelling of the vacuole (violet part). But after immersing the cell in a 5% salt solution, the cell becomes plasmolyzed and water moving in the cell goes out, thus, the vacuole shrinks. The turgid cell does not burst because of the cell wall and remains intact in a plasmolyzed cell because of the its rigid property and resistance to rupturing.

Factors affecting the integrity of Cell Membranes

The effect of temperature on cell membrane is shown by A, B and C. Color intensity was used as an indicator of the damage done to the membranes. A has the greatest color intensity, followed by B and C. These results show that at room temperature, little or no damage and stress is done to the membranes. At low temperatures (like the temperature inside the refrigerator), there is damage and stress done to the membranes. The most damage and stress is done to the membranes if the cells are subjected to high temperatures (like the temperature of the water bath). Heating the membranes, molecules start to spin and vibrate faster. The water will expand too, disrupting the membranes. Lipids become more fluid as temperature goes up, making the membranes fragile. Heating proteins, the amino acids will untangle and break apart, forming holes that will destroy the structure. Any pigment will spill out indicating the intensity of the color.Slides D and E show the effect of organic solvents on cell membrane integrity. The color intensity of E(treated with acetone) was greater than that of D(treated with chloroform). This shows that acetone has done more damage to the membranes and thus a stronger organic solvent than chloroform. Because the cell membranes outer layer is nonpolar (hydrophilic), nonpolar organic solvents would cause damage to the membrane and pigments would escape out of the cell.

Slides F and G shows the effect of pH. Slide G, which was treated with HCl, has a greater color intensity than F. This outcome shows that HCl, an acid, causes more damage to the membranes than does NaOH, a base. Extreme pH causes membrane proteins to denature. The lower the pH, the more protein denatures, allowing pigments to leak out of the cell.

ImbibitionImbibition is the absorption of fluid by a solid or colloid that results in swelling. The experiment showed that wood is a good imbibant of water while wood and rubber are good imbibants of kerosene. In imbibition, living cells are not necessary for the process to take place. In seeds, both living (seed itself) and dead (seed coat) absorbed water and are involve in the process. Imbibition is important to seed germination because its swelling effect causes the seed coat to rupture and allows radical to move downward forming the root. Movement of water through the stem

In the experiment, the xylem tissues of the pechay stalk were stained with the eosin dye proving that water moves up the stem through the xylem tissues.

Comparison of the Cuticular and Stomatal TranspirationThe petroleum jelly decreases the rate of transpiration of the leaves. Leaf A, not covered with the jelly, turned out to be the driest because nothing obstructs the stomata on the surface of the leaf. Leaf B, upper surface covered, is next because inspite of the jelly on the upper surface, the lower surface containing more stomata is still exposed. Leaf C, lower surface covered, is second least dry and leaf D as least dry because all the stomata were covered reducing the rate of transpiration. GuttationGuttation was induced because of high root pressure and overly moist soil conditions. The difference of it with transiration is guttation is the exudation of liquid water from leaves caused by root pressure while transpiration is the loss of water in the form of water vapor or by evaporation.

REFERENCESBotany: An introduction to Plant Biology (4th edition). 2009. James D. Mauseth. P.267http://bio1151b.nicerweb.com/Locked/media/ch07/07_13WaterBalanceP.jpghttp://www.biologymad.com/resources/beetroot%20pigment2.doc

EXERCISE 13RESPIRATION

INTRODUCTIONCellular respiration is the catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP. (Campbell, 2009)

In the process, it results in the release of both carbon dioxide and water.

HYPOTHESIS

If the products of photosynthesis are utilized in the process of cellular respiration in order to generate ATP, then cellulose and glucose are the materials that undergo a series of processes in order to release carbon dioxide and water as well as energy in the form of heat.

OBJECTIVESThe exercise mainly aims to achieve an understanding of cellular respiration in plants in relation to the role of the reactants, the details of its main processes and the manufacturing of its products.Specifically, this study aims to: Create an understanding of the role of oxygen in plant cellular respiration Mark how heat is produced by germinating seeds Depict the processes that allow that generate carbon dioxide among soaked seeds

RESULTS Use Of OxygenSetup A (germinating seeds): Change in color of the red ink in the adjacent bottle Setup B (killed seeds): No change in either bottle

Production of Heat Energy

Setup A (germinating seeds): Steady rise in temperature as time passes by Start: 37 degrees After 30 minutes: 37.7 degrees After 1 hour: 38.5 degrees Setup B (killed seeds): No change in temperature at any time during the study Start: 36 degrees After 30 minutes: 36 degrees After 1 hour: 36 degrees

Production of Carbon Dioxide

The water in the adjacent flask became blurry. Also, there was an evident change in its color

DISCUSSIONS Use of OxygenThe change in color of the ink can only be seen in Setup A because the germinating seeds are undergoing cellular respiration whereas the killed seeds demonstrate no change at all. The reason for this is because of the use of oxygen in the process of cellular respiration. When the seeds use oxygen, they release carbon dioxide. This carbon dioxide then reacted with the water in the adjacent bottle thus forming carbonic acid (the lighter colored liquid that replaces the red ink). Production of Heat EnergyIn the earlier hypothesis, it was discussed that ATP is released during cellular respiration in the form of heat energy. We therefore conclude that because the germinating seeds undergo cellular respiration, the temperature rises in the Setup A flask because of this release of heat whereas the killed seeds do not undergo any change because they do not respire. Production of Carbon Dioxide

There was a noticeable change in color of the blue solution as well as in the quality of the water because it became blurry. This can be explained by the carbon dioxide production of the plant while respiring. As the seeds produce carbon dioxide, it mixes with the water, forming carbonic acid. We know it is carbonic acid because the change in clarity of the water indicates that it has become acidic.

Part Further Study Questions

Aerobic Respiration: Occurs only if free oxygen is present, the process of glycolysis and the Krebs cycle occur in different places with the former in the cytoplasm and the latter in the mitochondria with glucose being completely oxidized into carbon dioxide and water. (occurs in plant and animal cells)

Anaerobic Respiration: Functions when there is a lack of free oxygen, the whole process occurs in the cytoplasm with glucose incompletely oxidized (occurs in muscle cells lactic acid fermentation; some fungi and bacteria in the formation of yeast alcohol fermentation)

Factors affecting cellular respiration: Many factors affect the process of cellular respiration but we can point out three that may serve as primary influences.

The amount of nutrients such as fats, proteins and carbohydrates the more nutrients available, the more energy is produced. Also, the type of nutrients supplied can affect the amount of energy that can be transformed because each nutrient possesses its own set of qualities that may affect cellular respiration.

Temperature of the environment the higher the temperature, the faster the rate of cellular respiration.

The state of a cell this mainly affects the rate of transforming the nutrients into energy. Working cells would have a higher rate of respiration as opposed to dormant cells.

REFERENCESBiology 8th Edition (2009) Neil A. Campbell & Jane B. Reecehttp://www.preservearticles.com/201101042471/differences-between-aerobic-and-anaerobic-respiration.htmlhttp://www.ehow.com/list_6417883_factors-affecting-cellular-respiration.html

EXERCISE 12PHOTOSYNTHESIS

INTRODUCTIONPhotosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar.

HYPOTHESISWhen light energy is absorbed by autotrophs with the aid of chlorophyll, water and carbon dioxide are the raw materials needed to produce molecules of glucose and release oxygen.

OBJECTIVESThis exercises intention is to determine the role played by the reactants in photosynthesis and their overall effect to the products and the reaction itself.This study aims to: Determine the importance of chlorophyll, light and carbon dioxide in photosynthesis Note the discharge of oxygen And to demonstrate the separation of the chloroplast pigments

RESULTS The Role of Chlorophyll in Photosynthesis The Role of Light in Photosynthesis

The Role of CO2 in Photosynthesis

Color Intensities (+, ++, +++) With Hydrilla Set up A(boiled water)+ Set up B(boiled water and sodium bicarbonate)++ Without Hydrilla Set up C(boiled water and sodium bicarbonate)+++ Set up A has less air (oxygen) bubbles compared to Set up B

Oxygen Liberation in Photosynthesis

After several minutes, air bubbles begin to rise up to the end of the inverted test tube.