Botany Laboratory LBBION Term 1 2024-2025 PDF

BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 THE CELL CYCLE abnormalities. For example, one has 46 CELL DIVISION chromosomes and one c...

BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 THE CELL CYCLE abnormalities. For example, one has 46 CELL DIVISION chromosomes and one cell has 47 – resulting in In plants, this division of cells occurs in abnormalities, mutation, or disease. When cells special tissues called meristems. keep on dividing without the capsule, this results This results in daughter cells that look in cancer cells. exactly like the parent cells. Some of the functions of cell division are for STAGES asexual reproduction, growth and development, and tissue renewal. The ultimate function of cell division is to produce daughter cells. INTERPHASE CHROMATIN No chloroplast = form of storage cell The nuclear envelope is intact, and no dense uncoiling of chloroplast in this phase Chromatin is a genetic material or a macromolecule comprising of DNA, RNA, and proteins which result in the formation of chromosomes within the nucleus of eukaryotic organisms. When the cell is about to divide, it must be prepared so that each cell will have the exact copy of the DNA. MITOTIC STAGES The helix (3) will be cut in the middle, and with the help of other proteins, they will be replicated, forming sister chromatids. When mitosis happens, the helix will have a spindle fiber stretching out and pulling away the sister chromatids, leaving two daughter chromosomes at opposite poles of the cell. PLANT CELL CYCLE Prophase - nuclear membrane will start to disintegrate and will slowly disappear. Spindle fiber forms around and chromatin materials are starting to condense. - Thread-like formations Late Prophase - nuclear membrane is gone. We can now see the dense chromosomes Metaphase - the chromosomes, attached to microtubules at their kinetochores, are all Under G1: This is where cells undergo at the metaphase plate. The spindle is growth and assimilate materials. complete. Under S: DNA synthesis for the preparation - The thread-like surrounding the for mitosis, it acquires materials metaphase plate are spindle fibers, particularly nucleic acid for DNA they pull the chromosomes. duplication. Anaphase - the microtubules attached to Under G2: Everything must be duplicated the kinetochores are pulled away from each already. other, breaking the connection of the sister Under M: This is where cells divide. chromatids. One copy is transferred to one pole, and the second to another. Each stage has a checkpoint in order for the cells - Breaking of the plate, the cytoplasm to know the condition or abnormalities in the is breaking from the middle DNA duplication. The cell does not allow - The start of the cytokinesis BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 Telophase - when they continue to break, it Duration of stage = number of cells at stage/total will form the newly-born two daughter number of cells x 16 hrs./cycle x 60 minutes/hr cells. The two daughter cells are identical to each other. PHOTOSYNTHESIS Q&A from Pre-lab Discussion: INTRODUCTION 1. What happens to the vacuole during It is the process whereby green plants division? It will disappear. The rest of the convert the radiant energy of light into organelles will disappear. chemical energy that is then stored in food 2. Will all of the organelles disappear? The molecules presence of the nucleus will depend on each Light, a green pigment, and carbon dioxide stage. Nucleus is present in prophase and must be present late prophase. Nucleus will reappear in late All living things are dependent on the telophase in its developing phase. products of photosynthesis for their energy, 3. What happens to the cell wall, will it for the raw materials necessary for growth expand? It doesn’t expand but it breaks. In and repair, and for the oxygen necessary for telophase, the middle line is where the life breakage starts. The process takes place in chloroplasts SUMMARY SUMMARY REACTION: 6CO2 + 12H20 -> C6H12O6 + 6H20 + 6O2^ 1. Interphase - a large, spherical nucleus, with the nuclear membrane intact, grainlike Glucose, the main product of chromosomes and one to two nucleoli. photosynthesis, follows three di erent 2. Prophase - a large, spherical nucleus with a pathways: nucleolus and nuclear membrane intact and with thickened, more distinctly ribbonlike 1. It is converted into other chemical chromosomes. The chromosomes may look substances required by plant cells (e.g., like a dish of spaghetti. cellulose in cell walls) 3. Prometaphase - a cell in which the 2. It is converted into starch, a storage chromosomes appear as a loose knot in the molecule that can be broken down to center of the cell. The nuclear membrane, if glucose again when the plant requires it still present, is indistinct. The nucleolus 3. It is broken down during cellular may start to fade. respiration to release energy needed by 4. Metaphase - a cell in which the plants for growth and development. chromosomes are aligned in the equatorial plane of the cell. 5. Anaphase - a cell in which the chromatids are moving to opposite poles of the cell. 6. Telophase - a cell in which the chromatids, though fairly distinct, are close to the opposite poles of the cell. A cell plate may be forming at the middle of the cell. 7. Cytokinesis - two cells that appear to have finished dividing recently. These are the daughter cells and exact clones of each other. COMPUTING THE MITOTIC INDEX 1. In the light reaction, water is hydrolyzed and it happens in the chloroplast. Inside the STEPS chloroplast, there is the thylakoid. 2. In the process, oxygen is released as a waste Mitotic Index = number of cells in mitosis / total product. number of cells x 100 3. The primary products of light reactions are ATP and NADPH. 1. Count the number of cells from each 4. In the Calvin cycle, sugar is produced and column, excluding those undergoing CO2 is involved. mitosis and those without the presence of a nucleus or chromosomes. 2. Count the number of cells undergoing mitosis. 3. Input the numbers in the formula. CELL CYCLE DURATION STEPS BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 ABSORPTION SPECTRA AND ACTION SPECTRUM LIGHT INTENSITY Higher intensity of light or less distance of light source from the plant produces more oxygen bubbles, indicating that intensity a ects the rate of photosynthesis over time. It is limited to blue pigment (chlorophyll b) Chlorophyll a ranges within the red light WAVELENGTH At 50 cm, the number of bubbles increases over time, with more bubbles produced PRESENCE OF LIGHT under blue light and less under clear light. Blue light, with its shorter wavelength, is absorbed more by chlorophyll, boosting the rate of photosynthesis and oxygen LIGHT-EXPOSED NOT LIGHT-EXPOSED production. LEAF LEAF Clear light, being less e ective, produces less bubbles. Able to produce Unable to produce When the distance is doubled, bubble sugars in the starch, absence of a production decreases due to reduced light chloroplast of the bluish black color in the intensity. leaf, indicated by the leaf bluish black color CARBON DIOXIDE AS A REQUIREMENT FOR PHOTOSYNTHESIS The chlorophyll gains If the plants have energy through light remaining starch and is and carbon dioxide, in a dark environment, powering the the grains of starch will synthesis of starch begin to disappear within an amount of time COLORS/WAVELENGTH AND INTENSITY OF LIGHT Independent variable = light intensity Dependent variable = distance between the leaf and light source The change in the color represents the carbonic acid formed or the addition of RESULTS carbon into the solution The solution will become more acidic RESULTS TEST TUBE OBSERVATIONS A Test tube A turned into a - Blown phenol pale yellow color when red blown with CO2. The - Without color remains the same hydrilla as there is no plant to verticillata consume the carbon Light: Clear, Red, Blue, and Green dioxide. 1. Distance: 50 cm vs 100 cm (at 40 W) B Test tube B turned into 2. Predict the result in this set up: - Blown phenol yellow when blown with Light Power: 40 W vs 100 W (at 50 cm red CO2. It transitioned back distance) - With hydrilla to its original color due BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 verticillata to the conversion of CO2 RESULTS to O2 in the solution. -> CO2 was synthesized by light-exposed hydrilla verticillata. C Test tube C retained its The color that travelled the farthest is - Unblown red color without CO2 green. phenol red and remained the same The color that travelled the least is - With hydrilla after light exposure. It yellow-brown. verticillata did not photosynthesize The distance travelled by the pigments because there was not indicate their solubility in their solvent and any CO2 to consume. a nity for the paper. Only pigment 3 (xanthophyll) reached the standard Rf value. Due to the fact that some chlorophyll The purpose of blowing air into the solution is to pigments are not visible to the naked eye, introduce carbon dioxide, dissolving the phenol green is the only pigment that we can red solution and forming carbonic acid. This then observe in plants through the naked eye lowers the pH level, causing a color change that because green cannot be absorbed by plants. serves as an indicator for carbon dioxide concentration. FUNCTIONS OF CHLOROPHYLL PIGMENTS Chlorophyll a - absorbs light from the When the carbon dioxide is absorbed by the orange to red and blue to violet spectrum. Hydrilla ventricillata, the solution becomes Chlorophyll b - absorbs light energy. less acidic and the pH level of the solution Carotene - safeguard plant tissues by rises, causing the solution to turn back to its assisting in the absorption of energy from original red color. singlet oxygen Phaeophytin - acts as the first electron SEPARATION OF CHLOROPLAST PIGMENTS BY carrier intermediary in plants’ Photosystem PAPER CHROMATOGRAPHY II Xanthophyll - light-harvesting pigments that can serve as structural entities within CHROMATOGRAPHY the LHC and compounds that protect It is the method of separating closely photosynthesis from the potentially related compounds, such in the case of damaging e ects of light. pigments, by allowing the mixtures of substances to di use through an absorbent BENEFITS OF CHROMATOGRAPHY called chromatogram. Allows us to see colorful pigments hidden inside the leaf. COLOR BANDS Examines a variety of compounds and find mixtures that have the desired properties. BAND COLOR PIGMENT CELLULAR RESPIRATION Yellow Carotene INTRODUCTION It is the process of releasing the energy Yellow-gray Phaeophytin stored in food. It takes place in all living cells and makes Yellow-brown Xanthophyll adenosine triphosphate (ATP) and other energy-liberating molecules available for Bright green to blue Chlorophyll a cellular work. green The process begins in the cytosol (glycolysis phase) and progresses onto the Yellow green to olive Chlorophyll b mitochondrion where the rest of the phases green occur, namely - Acetyl coA formation DISTANCE TRAVELLED (Rf) - Krebs cycle The retention factor (Rf) is a ratio that can - Electron transport chain be calculated and compared to known Rf Respiration is a chemical process. standards to identify unknown compounds. The complete process takes place only in the presence of oxygen, and is described as aerobic respiration. In the absence of oxygen, cells undergo fermentation or anaerobic respiration which makes little to no ATP. NOTE: When holding the filter paper, hold it at the edges not on its broad surface. BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 acidic. Tubes 1 and 2 are to show color GAS EVOLVED IN AEROBIC RESPIRATION change due to the CO2 dissolved in water, forming in carbonic acid. SOME ENZYMES W/ OXIDATION REACTIONS SET-UP OBSERVATIONS INTRODUCTION Flask with 40% KOH This set-up reacted first Browning and discoloration are often and produced small caused by the oxidation of certain organic white precipitates. There compounds such as phenols that are were few to no bubbles present in the cells. observed and the The oxidations are catalyzed by oxidases Ba(OH)2 solution (acting on oxygen) or peroxidase (acting on remained clear. naturally occurring peroxidases) Flask with This set-up produced a EFFECTS OF DIFFERENT TREATMENTS ON germinating seeds significant amount of OXIDASES AND PEROXIDASES white precipitate more than set-up A. Co2 bubbles were produced and caused the Ba(OH)2 to turn cloudy. C02 was given o by the germinating seeds. A white precipitate was observed in both set-ups – this is known as barium carbonate which was formed when CO2 reacts with Ba(OH)2. This indicates that germinating seeds produce CO2 as they The treatments that caused the browning of respire. apple and potato are 3.1, 3.4, and 3.5. Apple and potato both contain polyphenol oxidase that catalyzes when exposed to oxygen BALANCED CHEMICAL REACTION: Ba(OH)2 + from air. Peroxidase, an enzyme of fruits CO2 -> BaCO3 + H2O and vegetables, also reacts with guaiacol that causes browning in the presence of EFFECT OF SUBSTRATE ON FERMENTATION hydrogen peroxide. Ascorbic acid inhibits the browning of the freshly peeled fruit because of its ability to AMOUNT OF GAS DISPLACED (ML) IN VARIOUS reduce oxidized substrates. SUBSTRATES THROUGH TIME Treatments 2 and 3 can slow down browning, specifically ascorbic acid and boiling water. The warm lye bath allows polyphenol oxidase to remain active which will allow the potato to turn reddish-brown as it reacts with oxygen from air. When the temperature is increased, the PPo will be denatured that will prevent the potato from browning. The tube that showed the greatest amount Cytochrome C oxidase is an oxidase that of gas displaced is sucrose + yeast. catalyzes the final step in ETC as it The gas came from alcohol fermentation facilitates the transfer of electrons from where the sugar was consumed by the yeast cytochrome C to oxygen. and is broken down into 2 pyruvate In the 3.1 set-up, the cucumber showed no molecules. The pyruvate molecules are then e ect when the hydrogen peroxide was oxidized into acetaldehyde, producing CO2. added. On the other hand, in the 3.4 set-up, The respiration was faster in tube 2, the solution and cucumber turned containing 25 mL of 10% glucose solution reddish-orange immediately after and 25 mL yeast suspension. hydrogen peroxide was added. When sugar was supplied, it was consumed by yeast causing a faster rate of ACTION OF CATALASE ON POTATO CELLS fermentation and in turn, yeast activity is TREATED WITH HYDROGEN PEROXIDE increased. Tubes with glucose and yeast, sucrose and yeast, and yeast suspension all showed color change. SET-UP OBSERVATIONS The color change indicates that the samples stated are acidic. However, it was initially H2O2 + freshly cut After submerging the expected that glucose and sucrose solution potato potatoes in hydrogen and yeast suspensions are not supposed to peroxide, it produced show any color change because they are not bubbles at the top. It also BOTANY LABORATORY LBBBION | Term 1 | 2024 - 2025 fizzed as a result of pyrogallol solution peroxide being broken into water and oxygen. Only the seeds with the set-up of water germinated while the other set-up H2O2 + boiled potato After submerging the containing pyrogallol did not. boiled potato in H2O2, a The bottle with water and seed showed layer of bubbles was more evidence of seed germination, which produced but it was is the presence of radicles. thinner as compared to The di erence in the amount of oxygen that of freshly cut consumed by the seeds in both set-ups potatoes. account for the di erence in their germination. In the set-up with water only, The gas that evolved in the freshly cut the seeds took in more O2 compared to the potato with H2O2 is oxygen. one containing pyrogallols. The enzyme catalase is present in the The pyrogallol solution absorbs the oxygen freshly cut potato, which converts h2O2 in the bottle, causing a decrease in the into H2O and O. oxygen absorption of the seeds. - The evidence for this is the layer of Germinating seeds are used in this bubbles of oxygen gas that formed at experiment because they will show the top of the solution. remarkable changes when exposed to favorable conditions such as good amount of oxygen. BALANCED CHEMICAL REACTION: 2H2O2 -> 2H2 + O2 IMPORTANT NOTES The role of catalase in cellular metabolism What is the scientific name of onion? is that it catalyzes the dismutation of H2O2 ○ Allium cepa into H2O and O2. It is also responsible for What is the scientific name of potato? neutralization through decomposition of ○ Sollanum tuberosum hydrogen peroxide. What is the scientific name of the plant used in photosynthesis? TEMP READINGS OF GERMINATING AND BOILED ○ Hydrilla verticillata MONGO SEEDS THROUGH TIME What is the balanced chemical reaction of photosynthesis? ○ 6CO2 + 12H20 -> C6H12O6 + 6H20 + 6O2^ What is the balanced chemical reaction of cellular respiration? ○ Ba(OH)2 + CO2 -> BaCO3 + H2O What is the purpose of boiling the leaf under water? ○ To disrupt the membrane What is the purpose of ethanol? There is a gradual increase in Dewar flask A ○ To dissolve chlorophyll and remove which contains germinating seeds. On the the green color from the leaf other hand, there is a constant temperature What is the purpose of iodine? in B except after 24 hours. ○ To detect the presence of starch The change in temperature reflects the rate Why is there no black pigment in the middle of respiration and energy release. Higher of the lead? temperature in germinating seeds shows ○ There is no chlorophyll present active respiration and energy liberation. How does one handle a chromatography Carbohydrates are broken down into ATP; paper? lipids are broken down to ATP as secondary ○ Handle it by the sides fuel; and proteins or amino acids are broken What is the seed used for cellular down to ATP during starvation. respiration? Only about 40% of the energy is from ○ Mongo seeds glucose oxidation and stored as ATP, and What are the components used to form a 60% is released as heat. The heat released is precipitate? not e ciently utilized for plant ○ Carbon dioxide and barium metabolism. hydroxide EFFECT OF PYROGALLOL SOLUTION ON What is produced during respiration and GERMINATING CORN SEEDS some in heat energy? ○ ATP What is glucose? ○ A monosaccharide SET-UP OBSERVATIONS What is sucrose? ○ Needed to be hydrolyzed Seeds + water Radicles are seen What is the balanced chemical equation for Seeds + water + No sign of germination hydrogen peroxide? ○ 2H2O2 -> 2H2O + O2