Botany Lab - Pre-Lab 1 PDF

: CompositoN of ORg & NORG compounds WEIGHT A B (FW-DW) / + W 1 He MOSTURE) LINE GRAPHS aRE T...

: CompositoN of ORg & NORG compounds WEIGHT A B (FW-DW) / + W 1 He MOSTURE) LINE GRAPHS aRE THOSE SAMPLES? FRESH (g) living 100 NO -O What 5009 g00g ↓ · WEIGHT DRY (g) 1309 nog O OYEN DRIED (DW-AN)/TN] x100 (DRY ASH (g) 60g 809 - INCINERATED (AW/FW) x 100 ( PLANTS UMCRE THER OUN PRODUCE QUALITATIVE TEST FOR CARBONYDRATES : InHanOn/MONOSACACCHARIDE b RESPIRES : - : STARCH : PLANT STORAGE FOOD : CELLULOSE : CELL WALL ISTRUCTURAL PRIMARY MATERIAL : ENERGY BIOMLN-1 1. %: : TESTS : - BENEDICTS/BARFOEDS - IODINE  Elements: Population, Place, Time Format: Title, name of the author, and affiliation should be WRITING OF SCIENTIFIC PAPERS aligned at the center Rule: Limited to 15 words or fewer if possible Note: Don’t forget to designate a corresponding author SCIENTIFIC PAPER o Asterisk (*) is used as a symbol to designate the Description: A formal written report that allows scientists corresponding author either to share their original research or to review the o Corresponding author - contact person of the res published research of others. article o Integral part of the evolution of science. Benefit: Gives scientists the opportunity to learn about the ABSTRACT works of others and build upon such work. Process: Are published in scientific journals after a peer Description: Is a one or two paragraph condensation of review process. the entire work described completely in the paper. Main Goal: To inform o Should be a self contained unit capable of being o Writers must use clear, specific, and grammatically understood without the benefit of the text. Division: accurate language. o B - Background of the Study Table No. Two Types of Scientific Papers o O - Objectives of the Study o M - Methods REVIEW PAPER EXPERIMENTAL AND/OR o R - Results OBSERVATIONAL PAPER o C - Conclusion Condensed RRL There is intervention to get Should Contain: data. o The purpose of the study (the central question) The researcher will compile Data should be analyzed o A brief statement of what was done (Methods) previous studies about the and interpreted o A brief statement of what was found (Results) o A brief statement of what was concluded topic. (Discussion, in part) No methodology and results - and discussions INTRODUCTION Says what's lacking and - what needs to be improved PEER REVIEW PROCESS Description: papers are evaluated and then either approved or rejected by the reviewers. Importance: To avoid duplication of published results and ensure that only high quality papers with relevant and valid information can be shared within the scientific community. Predatory journals have been rampant in previous years. PARTS OF THE SCIENTIFIC PAPER TITLE Description: Should reflect the goal of the experiment performed, and the elements manipulated. o Complete, concise, and accurate description of the work DO | BLOCK 05191D 1  study ur worksheets too bffs Function: to present the question being asked and place o If competition lowers reproductive output then fruit it in the context of what is already known about the topic. size should be smaller when tree density increases. Composition: Background information that suggests why the topic is of interest and related findings by other scientists. METHODS Should Contain: Function: to describe all experimental procedures, o A description of the nature of the problem and including controls. current state of knowledge or understanding at the Note: The description should be complete enough to beginning of the investigation (background) enable someone else to repeat your work. o A statement of the purpose, scope, and general o If there is more than one part of the experiment, it is method of investigation in your study a good idea to describe your methods and present o Hypothesis/Hypotheses and predictions your results in the same order in each section. For a scientific paper: one paragraph of the introduction This may not be the same order in which the experiments is enough. were performed - it is up to you to decide what order of presentation will make the most sense to your reader. Make the methods as if you performed the experiment NOTE: o Numbering format, past tense Do not get lost in reviewing background information. The Introduction is meant to Explain why each procedure was done, that is, introduce the reader to your what variable(s) were you measuring and why? research. Do not summarize and evaluate Mathematical equations and statistical tests - are all past literature on the subject considered mathematical methods. (which is the purpose of a review o should be described in this section along with the paper). actual experimental work. Do not bombard it with too much Cite - If any of your methods is fully described in a information. previous publication (yours or someone else’s), you can Save your articles for the Discussion, where they cite that instead of describing the procedure again. become a powerful tool for comparing and o Example: The chromosomes were counted at interpreting your results. meiosis in the anthers with the standard Include only enough background information to acetocarmine technique of Snow (1955). allow your reader to understand why you are asking the questions you are and why your RESULTS hypotheses are reasonable ones. Just a brief explanation of the theory involved is Function: To summarize general trends in data without sufficient in the introduction. comment, bias, or interpretation. Description: Aims to summarize data and trends without bias INTRODUCTION: STATEMENT OF THE PURPOSE Composition: data and findings of the study and statistical tests applied to your data o conclusions about your original hypotheses are Function: expresses the central question you are asking saved for the discussion section and thus presents the variable you are investigating. Presentation: May be presented in figures and tables, but Examples: this may not substitute for a verbal summary of the o This study investigates the relationship between findings. tree density and fruit size Note: The text should be understandable by someone o The purpose of this study is to determine the effect who has not seen your figures and tables. of enzyme concentration on the reaction rate of.. o All results should be presented, including those Description: Define the origin of the problem and that do not support the hypothesis. describe the events which led to the topic. Example: o Incorrect: The results are given in Figure 1. o Correct: Temperature was directly proportional to INTRODUCTION: HYPOTHESIS metabolic rate (Fig. 1) Heart of the research paper Description: The explanation you are proposing for Statements made in the text must be supported by the certain observations. results contained in figures and tables. o It is a tentative answer to the question you have o The results of statistical tests can be presented in posed above. parentheses following a verbal description. o It should be accompanied by a prediction of results Example 2: Fruit size was significantly greater in trees expected under certain conditions if the hypothesis growing alone (t = 3.65, df = 2, p < 0.05). is correct. Function: Guide to the research work plan Based on: factual knowledge, experience, and observations Example: DO | BLOCK 05191D 2  study ur worksheets too bffs ○ For both graphs, and histograms, DATA PRESENTATION plot the independent variable on the Tables and figures - should be used when they are horizontal (x) axis and the a more efficient way to convey information than verbal dependent variable on the vertical description. (y) axis. Label both axes, including o They must be independent units, accompanied units of measurement. by explanatory captions. Drawings and photographs are used to ➔ allow them to be understood by someone who has not read the text. illustrate organisms, experimental apparatus, Do not repeat in the text the information in tables and models of structures, cellular and figures. subcellular structure, and results of o but do cite them, with a summary statement when procedures like electrophoresis. that is appropriate. Whenever possible, use a figure instead of a table. Relationships between numbers are more readily grasped when they are presented graphically rather than as columns in a table. 1. Tables Do not repeat information in a table that you are depicting in a graph or histogram. ○ include a table only if it presents new information. It is easier to compare numbers by reading down a column rather than across a row. ○ List sets of data you want your reader to compare in vertical form. 3. ○ Provide each table with a number (Table 1, Table 2, etc.) and a DISCUSSION title. ○ The numbered title is placed Function: To analyze the data and relate them to other above the table. studies. o To "analyze" means to evaluate the meaning of your results in terms of the original question or hypothesis and point out their biological significance. Should at least contain: o the relationship between the results and the original hypothesis, i.e., whether they support the hypothesis, or cause it to be rejected or modified. o an integration of your results with those of previous studies in order to arrive at explanations for the observed phenomena. o possible explanations for unexpected results and observations, phrased as hypotheses that can be tested by realistic experimental procedures, which you should describe. Note: Trends that are not statistically significant can still be discussed if they are suggestive or interesting, but 2. Figures cannot be made the basis for conclusions as if they were These comprise graphs, histograms, and significant. illustrations, both drawings and photographs. Provide each figure with a number (Fig. 1, NOTE: Fig. 2, etc.) and a caption that explains what Avoid redundancy between the Results the figure shows. and the Discussion section. ○ The numbered caption is placed Do not repeat detailed descriptions of the below the figure. data and results in the Discussion. Graphs and histograms can both be used to In some journals, Results and Discussions are joined in a single compare two variables. section, in order to permit a single ○ Graphs show continuous change, integrated treatment with minimal ○ Histograms show discrete repetition. variables only. DO | BLOCK 05191D 3  study ur worksheets too bffs o Name Year (N-Y) - In-text citations appear in This is more appropriate for brackets, and consist of the author(s) last name, as short, simple articles than for well as the document’s year of publication (e.g. longer, more complicated ones. Smith 2008). The end reference list appears in alphabetical order by author last name. CONCLUSIONS AND RECOMMENDATIONS THE COMPOUND MICROSCOPE The appropriate place to propose specific further study if that will serve some purpose, but do not end with the tired Description: Is an indispensable tool in botany as in all cliché that "this problem needs more study." biological sciences. o All problems in biology need more study. Function: It enables us to see plant structures too small to be seen by the unaided eye. o Do not close on what you wish you had done; To date, the light and electron microscope is in use. rather finish stating your conclusions and o Light microscope - uses glass lenses to focus light contributions. on the specimen. ➔ 1590s - the invention of the light microscope. REFERENCES ➔ Since then, numerous improvements and modifications to the performance of the This is the last section of a scientific paper. instrument itself. However, part of this References are listed by author using the CSE format. improvement depends on the development Papers are not referred to by footnotes as in literature of new techniques for specimen preparation. papers but are cited within the body of the text. o Electron microscope - either Transmission electron or Scanning electron. SUMMARIZING AND PARAPHRASING The ability to summarize and paraphrase the works THREE ELEMENTS NEEDED TO FORM AN IMAGE of other scientists is an important skill that every writer of a scientific paper should master. Source of illumination Specimen to be observed o Being able to explain other scientists’ works A system of lenses to focus the illumination on the specimen and to shows that the writer understands the concepts form the image and ideas that the original authors wanted to convey. Summarizing - the writer needs to identify the key features and ideas of a published work then write a PARTS OF THE MICROSCOPE shortened and simplified version that is different enough from the original. Mechanical Parts - those parts concerned with the Paraphrasing - restating information using one’s own support and adjustment of the optical parts. words. o Base o It involves expressing not just the key ideas, o Pillar but also the details. o Handle/arm o Inclination screw CITATION STYLES AND REFERENCE o Body tube FORMATTING o Ocular tube/draw tube o Revolving nosepiece Different scientific journals have different formats for o Dust shield citing the published work of other scientists in-text and in the reference (or literature cited) section at the end of o Adjustment screws: Course and Fine Adjustment the paper. Screws The Council of Science Editors (CSE) Style Manual is o Stage the most commonly used citation guide for papers o Mirror Rack published in the realm of natural sciences. Magnifying parts - those parts concerned with image The CSE Style Manual uses three sub-styles in citing enlargement of the specimen. published work: o Ocular/eyepiece o Citation Sequence (C-S) - uses numbers for o LPO in-text citations, either as superscripts or o HPO enclosed in parentheses or brackets in-line. The o OIO cited papers are listed in the Reference section Illuminating parts - those parts concerned with light in the order that they appear in the text (i.e. provision and regulation of the specimen. not alphabetically as in other style guides). o Citation Name (C-N) - All references in the THE MICROMETER reference list are organized alphabetically by author last name, and assigned a number according to their order in the list. This number is then inserted Microscope can be used not only to observe very small in the text in superscript font (e.g. 1) wherever the objects but also to measure the sizes or the specimen. work is cited. DO | BLOCK 05191D 4  study ur worksheets too bffs Micrometer - used as a scale to measure an object seen o Diameter of circular image seen through in a microscope. microscope Types of Micrometer: o Measured in micrometers o Ocular micrometer - a small circular piece of glass o Area of the slide which can be seen when looking that has uniformly spaced lines engraved on one down through the microscope. surface. The LPO is always used first because this allows a larger ➔ Inserted at the bottom of the ocular or area of the slide to be seen. eyepiece o This then allows you to choose which part of the ➔ Measures sizes of the cells specimen on the slide you want to view in further ➔ 50-100 equally spaced division marks detail at high magnification. (usually 100 divisions w/out value) o Before increasing magnification, the area you have ➔ Ruler in ocular lens chosen should be moved to the centre of the field of o Stage micrometer - aka objective micrometer view. ➔ Ruler image on slide ➔ 1 division = 0.01 mm (10 μm) ➔ 100-200 equally spaced division marks (usually 100 divisions) FINDING FOV UNDER LOW POWER Example: 1. Place the transparent plastic ruler on the stage so that the ruler’s edge is centered in your field of view under low power. 2. Position the ruler so one of the millimeter markings is just visible to the left side of your circle in your field of view. 3. Count the number of whole millimeters that you see, and estimate the fractions of millimeters that you see. In the above diagram, we see 4 whole millimeters and about ½ of a millimeter. If we switch to the medium power objective, the FOV becomes smaller. 4. It becomes very difficult to accurately estimate the diameter of the FOV when we switch to a higher power. Therefore, we can perform a simple calculation to determine the FOV under high power. MEASURING OBJECTS UNDER THE MICROSCOPE WITH OR WITHOUT USING A MICROMETER 5. Follow the formula: Use the Field of View (FOV) - diameter of the circle of Count the number of cells in one straight light. line. Estimate if bungi bungi DO | BLOCK 05191D 5  study ur worksheets too bffs C-backbone - they all have a carbon chain. The o carbon backbone influences the shape of the molecule. o Diversity of organic molecules comes from the attachment of different functional groups to the carbon skeleton. o R group - amino group. Ranges from one hydrogen atom to a complex ring compound. o water, oxygen, minerals, etc. Organic + inorganic = compounds compromising life PERCENT COMPOSITION OF ORGANIC AND MEASUREMENT OF MAGNIFICATION OF IMAGES INORGANIC COMPOUNDS IN PLANTS 1. Weigh the fresh sample Description: defined as the number of times an object is Get the Fresh Weight (living weight) enlarged by the magnifying lens or the number of times a drawing or image is enlarged or reduced from the original 2. Place the sample in an oven for drying size of the object. Time duration and temperature vary Calculate the total magnification of the microscope depending on the specimen and method. with each objective: During the drying period, the water present o Total magnification = magnification of eyepiece x in the same is evaporated away. magnification of objective Get the dry weight (after oven drying). Calculate the drawing magnification: o Drawing magnification = drawing size (mm)/actual size (mm). 3. Dry sample will be incinerated Measurement of Magnification of Images: Incineration - the sample will be placed in a crucible. The sample is heated at an elevated temperature. ○ Organic matter in the sample will be burned in the presence of oxygen and it will be converted into carbon dioxide and oxides of nitrogen. Crucible - personal laboratory container that can withstand very high temperatures. After incineration, you will obtain ash. ○ Ash - inorganic residue after water and organic matter have been removed. Get the Ash weight (after incinerating). THE CHEMICAL COMPONENTS OF A PLANT CELL BIOLOGICAL ORGANIZATION QUALITATIVE TESTS IN CARBOHYDRATES How life is constructed. All living organisms are organized. Carbohydrates - are almost universally used as an The complex organization of living things begins with the energy course in living organisms. cell. o Includes simple sugar molecules and chains of o The cell is the most basic unit of life. sugars o Cell is composed of inorganic and organic o Typical ratio: CnH2nOn molecules. Monosaccharides - basic unit Inorganic compounds - compounds that do not contain a o Are simple sugars that consist of only a single carbon atom. sugar molecule. o Carbon atom should be bonded to another carbon o E.g. glucose, fructose, galactose and hydrogen atom. Disaccharides - contain two monosaccharides bounded Organic compounds - include compounds that always by a glycosidic bond. contain carbon and hydrogen atoms. o maltose (glucose+glucose) - malt sugar found in o Biomolecules - Carbohydrates, proteins, lipids, and germinating seeds nucleic acids. DO | BLOCK 05191D 6  study ur worksheets too bffs o sucrose (glucose+fructose) - table sugar Hemiacetal (reducing sugar) vs Acetal o lactose (glucose+galactose) - sugar found in milk o Hemiacetal - contains one alcohol and one ether Polysaccharides - polymers of monosaccharides group that are attached to the same carbon. In o Function as a short-term energy storage molecule equilibrium with aldehyde and ketone. or as structural components of cells. o Acetal - contains two ether groups that are attached o Starch - plants storage food (glucose) to the same carbon and is not in equilibrium with o Cellulose - found in plant cell walls. A aldehyde and ketone. polysaccharide that contains polymers or chains of Sugars with a hemiacetal are in equilibrium with a glucose. ring-opened form containing an aldehyde and will react as Presence of carbohydrates can be detected using the a reducing agent to certain oxidizing metals salts such as following tests: Cu2+ and Ag+. o Benedict’s o Barfoed’s o Iodine BENEDICT’S TEST Test that detects reducing sugar. o Usually monosaccharides and disaccharides. Reducing sugars o In their free or open structure, they have aldehydes and ketones. o In their ring structure, they have hemiacetals. A sugar without a hemiacetal is a non-reducing sugar. Has copper sulfate (CuSO4) o Acetals are “locked” and not in equilibrium with a o CuSO4 will react with functional groups (aldehydes, ring-opened form with an aldehyde. They will ketones, hemiacetals) and involves the redox therefore not react as a reducing agent. reaction. o Sucrose is a combination of glucose and fructose Redox Reaction - includes reduction and oxidation that are joined together by a glycosidic bond. After / reactions. dehydration, when they are connected by a · ODENS AIDENDES/ o OIL - Oxidation is Loss of Elections glycosidic bond, the hemiacetal region disappears HETOMES ➔ X is oxidized by Y and becomes an acetal region. Therefore, sucrose ➔ X loses electrons is considered a nonreducing sugar. SugAR-HEMIACETALS · ON Ring ➔ X is a reducing agent ➔ X increases in oxidation number COPPER reaCTS /ALDEHYDE OXIDISEL Oxygen o RIG - Reduction is Gain of Electrons ➔ Y is reduced by X ➔ Y gains electrons ➔ Y is an oxidizing agent ➔ Y increases in oxidation number BARFOED’S TEST Test that detects reducing monosaccharides and not reducing disaccharides. o Disaccharides will react slower. Redox Reaction o Addition of acetate and acetic acid reacts faster with monosaccharides. o Reducing monosaccharides will react to the reagent faster than disaccharides since disaccharides are made of two monosaccharides, so before they react to the reagent, they have to get hydrolyzed first. Barfoed’s testing agent (color blue) contains copper sulfate, acetate, and acetic acid o Acetate and acetic acid give acidic pH in the solution. DETECTS o Acidic ph is unfavorable for redox as it prevents it. REDUCNG SUgARS Reducing sugars or reducing monosaccharides are strong reducing sugars, whereas reducing disaccharides are MAJORIT weak reducing sugars. REDUCING SUgAR (+) brick red precipitate MAJORITY NON REDUCING SUSAR DO | BLOCK 05191D 7  study ur worksheets too bffs o Transport proteins - allow substances to enter and exit the cell. AMINO ACID Description: the basic unit of proteins. Each amino acid has a central alpha carbon atom bonded to a hydrogen atom, amino group, carboxyl, and the R group (remainder or side chain of the molecule). There are 20 amino acids that differ according to their particular R group. Ranges from a single atom or hydrogen atom to a complicated compound. o C-backbone o Carboxylic acid and amine group on polar opposites o R-group and H on opposite poles. IODINE TEST Test that detects the presence of starches o Composed of hundreds of glucose molecules either occasionally branched or unbranched (can form helical form). Iodine reagent contains iodine PEPTIDE BOND AND POLYPEPTIDE o Color orange, yellow, reddish-orange, or yellowish Peptide bond - resulting bond of two amino acids. brown. o Linked between the carboxyl of one amino acid and o Iodine molecules form a polyiodide chain the amino group of another amino acid. ➔ If there is starch in the sample, the o Joined by a dehydration reaction (releasing water) polyiodide chains will insert in starch helix and form the amylose iodine complex. Polypeptide - chain of many amino acids. (+) purple black fluorescence o Final shape of the protein determines its function in the cells. FOUR LEVELS OF STRUCTURE IN PROTEINS PROTEINS Description: of primary importance to the structure and 1. Primary structure function of cells. determined by the sequence of amino acids. o Structural proteins - provide structural support to the cell. o Enzymes - proteins that can speed up a chemical reaction in plants. DO | BLOCK 05191D 8  study ur worksheets too bffs 2. Secondary structure o Glycerol - a compound with three hydroxyl groups. involves the hydrogen bonding in amino Hydroxyl groups are polar; hence, are soluble in acids causing the polypeptide to form a helix water. (coils) or a pleated sheet (folds). o Fatty acids - long hydrocarbon chain that is typically 16 to 18 carbons in length. They have a carboxyl 3. Tertiary structure group at one end and a carboxyl or acidic group is folding and twisting of the polypeptide results polar. in the final 3D shape of a polypeptide. o When they are joined together, the polarity disappears and they form a triglyceride (non-polar 4. Quaternary structure and immiscible in water). occurs when two or more polypeptides are joined to form a single protein. SATURATED-W/0 DOUBLE BONDS UNSATURATED-W/DOUBLE BONDS - STRONGET - SENSITIVE TO OXIDATION GREASE SPOT TEST Simple test for lipids Lipids have higher boiling point than water Lipids have high boiling points and can absorb enough heat from the air and vaporize. The presence of translucent spot indicates the presence of fats. BIURET’S TEST (+) translucent mark on paper Test that detects polypeptides. Reagent is Alkaline CuSO4 (blue) Biuret reagents react to peptide bonds o The more peptide bonds, the stronger the color reaction (+) purple solution LIPIDS - rembuare Lipids - are a diverse group of molecules and they are insoluble in water. (non polar ( -do not consist of monomers o Diverse in form and structure. -mostly hydrocarbons / Affinity For -little no water Forms: O phospholipids o Fats - well-known lipid and used for long-term (cell membrane ( energy storage and insulation. · steroids (hormones] o Oils - utilized for long-term energy storage in plants. o Waxes - produced by plants and animals and are R GLYCERIDEs used for protection to prevent water loss. Fatty acids and Glycerol - basic units of lipids. o Bonded by Ester bonds. 3 OH &H) NEEDS TO BE PROPPED SUDAN DYE TEST L FAITY ACDS & CYCEROL - ↳ LONG HYDROCARBON 3 CARBONYDRATE It BUT ORDER ON & TO N MERGE-IAN FORMS AS A BE USED BY PRODUCT TO BREAF UP TRIGLYCERIDE O the eND W/ACID GROUP. HYDROLYSIS - H1O breAES UPS TRIgLYCERIDE DO | BLOCK 05191D 9  study ur worksheets too bffs Sudan dye - Lipid soluble dye and insoluble to water Two parameters are expected in positive results of the VACUOLE Sudan IV test: Description: bounded by vacuolar membrane/tonoplast o Layers - you should see two layers. Two layers o In a mature living plant cell, 90% or more of the indicate the presence of water-insoluble volume may be taken up by one or two central substances. vacuoles. o Colors - you should see red color on the top layer. Functions: The Sudan IV will migrate to the top layer and color o Cell growth it red. This indicates that the top layer is fat. o Cell pressure and pH maintenance (+) remnant of red spots o Helps in organelle breakdown and digestion (-) Negative result will only exhibit one layer instead of o Recycle certain materials two. o Storage of numerous cell metabolites and waste products. THE PLANT CELL Cell sap - found inside the vacuole. o Slightly to moderately acidic. All living organisms are composed of cells and start life as a single stem. Cell - basic function and structure of life. Plant cell - a eukaryotic cell (generally large and complex cells) o Complex cell because of the organelles present inside the cell. o Organelles - have specific functions inside the cell. PLASTIDS Description: a group of membrane-bound organelles occurring in photosynthetic eukaryotic cells. Chloroplasts - green, site of photosynthesis Leucoplasts - colorless, storage of starch or oil (e.g. amyloplast) o Common in higher plants (plants that have advanced characteristics o Amyloplast - leucoplast that synthesizes and stores starches WATER BALANCE OF PLANT CELLS o Elaioplast - leucoplast that synthesizes and stores Tonicity - effect of the surrounding solution on the cell. oils Isotonic solution - there is no movement of water into the o Proteinoplast - leucoplast that is a site for enzyme cell activities as it contains crystalline bodies of proteins o Cell becomes flaccid (limp) Chromoplasts - colored or pigmented, produce and store o Water concentration is equal both inside and pigments outside the cell Bryophytes - most primitive plant groups Hypotonic solution - plant cell swells until the wall o E.g. mosses, liverworts, hornworts opposes uptake Plastids of all types develop from proplastids which are o Cell is turgid (firm) small, pale green, and colorless organelles. o Water concentration is higher outside the cell so the o Frequently divide and become distributed water moves inside the cell towards the vacuole. throughout the cell until they grow and develop into ➔ Vacuole will exert pressure and push against specialized plastids. the cell wall and vice versa; hence, the plant cell does not burst (unlike animal and human cells since they don’t have cell walls) Hypertonic solution - plant loses water and shrinks o Plasmolysis - lethal effect in plants where the membrane pulls away from the cell wall causing the plant to wilt o Water concentration is lower outside the cell DO | BLOCK 05191D 10  study ur worksheets too bffs ○ Present in aquatic plants, petioles of bananas, and leafstalks. 2. COLLENCHYMA Description: Sides of the young stems and in the stalk or midrib of leaves. ○ With unevenly thickened primary cell walls. Protoplast is alive at maturity. Function: Mainly for support and strength Present in tendrils, young stem, and petioles. VACUOLE CRYSTALS ○ Petioles - leafstalk (they are the Description: crystals formed inside the vacuole. same) 3. SCLERENCHYMA Description: With thick secondary wall with TYPES OF PLANT CELLS lignin Cells die at maturity, protoplast is dead Most common: sclereids and fibers 1. PARENCHYMA ○ Sclereids - short cells that are Description: With thin primary cell walls and variable in shape and are common protoplast is alive at maturity. in the shells of nuts and stones of ○ Most abundant of all cell types and fruits, such as cherries and are found in almost all major parts peaches. of higher plants. ➔ Pears owe their slightly Chlorenchyma - photosynthetic gritty texture to the parenchyma presence of clusters in ○ Have numerous chloroplasts sclereids. Storage parenchyma - contains lots of ○ Fibers - long tapered cells that often amyloplasts. occur in groups or clumps. ○ Function mainly in food and water ➔ Abundant in wood, inner storage bark, and leaf ribs (veins) ○ Have no chloroplasts of flowering plants Aerenchyma - parenchyma cells with large Function: for protection, water transport, air spaces. and support. ○ Provide aeration (?), plant buoyancy, and support ○ Abundant in water lilies and other aquatic plants Stellate parenchyma - highly branched parenchyma cells connected to each other by means of branches. ○ Star-shaped cells ○ Large volume of intercellular spaces DO | BLOCK 05191D 11  study ur worksheets too bffs MATERIAL TRANSPORT IN PLANTS Plasma membrane (cell membrane) - outer boundary of the cell. o Regulates the movement in order to maintain the proper balance of ions, water, carbon dioxide, nutrients, and other molecules. o All cell membranes are semi-permeable or allow free movement of some substances and control the movement of other substances. Chemical proportions within the cell and outside of the cell are different. TYPES OF ENERGY TRANSPORT Transport across the membrane can either be passive or WATER POTENTIAL (Ψw) active depending on the need for energy input. Description: free energy of water (free to diffuse). 1. Passive transport o Measure of the potential energy in water, or the Do not require energy or ATP since the given difference in potential energy between a movement of molecules is along the given water sample and pure water. concentration gradient. The potential of pure water (Ψwpure H2O) - is ○ Movement is from an area of high designated a value of zero (even though pure water concentration to an area of low contains plenty of potential energy, that energy is ignored). concentration. Water’s capacity to do work can be changed in other ways: 2. Active transport Transport mechanism of substances that use When water adheres to a Consider a small beaker of energy to move against the concentration substance, these water water; if it is pure water, it gradient. molecules form hydrogen can flow, move, dissolve ○ Movement is from an area of low bonds to the material and material, and hydrate concentration to an area of high are not as free to diffuse as substances, but if a sponge concentration. are other water molecules is added, water molecules (meaning their capacity to adhere to the sponge do work has decreased). material and can no longer flow or easily dissolve things. COMPONENTS OF WATER POTENTIAL TYPES OF PASSIVE MOVEMENT TRANSPORT MECHANISMS Ψw = water potential of a cell. Diffusion - tendency for molecules to spread out evenly o Plant cells usually have a negative water potential, into the available space. unless they are in equilibrium with pure water. o Movements of molecules from an area of higher ➔ Such cells are fully turgid and have a Ψ concentration to an area of lower concentration. (water potential) = 0. Osmosis - refers to the movement of water through a SOLUTE POTENTIAL (Ψs) semi-permeable membrane o from a region of high water concentration to a Ψs = solute or osmotic potential. region of low water concentration or a region of low o The contribution made by dissolved solutes. solute concentration to a region of high solute o The addition of solute lowers the water potential of concentration. the solution proportionally. It is the effect that solutes have on water potential. Facilitated diffusion - movement of substances is o In pure water, no solutes are present and osmotic facilitated by membrane proteins. potential is given the value of 0.0 MPa. Adding solutes can only decrease water’s free energy. DO | BLOCK 05191D 12  study ur worksheets too bffs o Water molecules interact with solute molecules and 2. Flaccid cell placed in hypertonic solution = water cannot diffuse easily; therefore, osmotic potential is potential is out of cell = plasmolysis always negative. Plasmolysis - the cell membrane retracts and clumps at the middle. Water moved out of the cell PRESSURE POTENTIAL (Ψp) Ψp = pressure or turgor potential. o The effect water has on water potential. o Is related to the counter-pressure exerted by the cell wall as the expanding vacuole presses the plasma membrane against the cell wall if a plant cell is placed in a hypotonic medium. Water is directly proportional to pressure. o If water is under pressure, the pressure potential increases and so does water potential. o If pressure decreases, so do the pressure potential and water potential. Pressure can be: o Positive - when something is compressed. o Negative - when something is stretched. Potential is measured in: o Units of pressure, usually megapascals (MPa) or INCIPIENT PLASMOLYSIS bars Description: initial stage of plasmolysis o Stage wherein the protoplast has lost just enough water to pull slightly away from the wall. o Osmotic condition where 50% of the cells are plasmolyzed. Ψcell = Ψs = Ψs of surrounding solution WATER RELATIONS IN PLANT CELLS 1. Flaccid cell in pure water = water potential is into cell = cell becomes turgid. When the cell is put in a hypotonic solution, water moves into the cell, causing the vacuole to get bigger. ➔ It will then press against the cell membrane, and the cell wall will exert pressure against the cell membrane. Although plant cells cannot absorb so much water that they burst, water loss can be a serious problem.. o Water moves out of the cell, osmotic potential becomes slightly more negative, and the pressure potential drops rapidly. o Long before the cell reaches equilibrium it loses so much water that the protoplast shrinks in volume Note: solutes don’t move. In tonicity, we are only looking at the movement of water. and no longer presses against the wall. DO | BLOCK 05191D 13  study ur worksheets too bffs REFERENCES Incipient plasmolysis - point at which protoplast has lost Notes from the discussion by Sir John Paul Domingo just enough water to pull slightly away from the wall. o Up to that point, the cell has lost very little water, so De La Salle University PowerPoint Presentation its volume change and osmotic potential change have not been great. o Because the pressure potential is now zero, the water potential equation is The cell has become plasmolyzed - If the cell has not reached equilibrium at the point of incipient plasmolysis, it continues to lose water, and the protoplast pulls completely away from the wall and shrinks. o Water potential continues to become more negative entirely because of the osmotic potential as solutes become more concentrated. IMBIBITION Description: a transport mechanism that does not require a semi-permeable membrane. o Results in swelling of material or enormous increase in volute. o Type of diffusion and unrelated to osmosis. o Initial step in the germination of seeds. o Water is attracted to and adheres to the internal surfaces of materials like cellulose, lignin, and starch (materials that have permanent suspension of fine particles). o E.g. absorption of water by seeds and dry wood. Molecules (cellulose and starch) - usually develop electrical charges when they are wet. o The charged molecules attract water molecules, which adhere to the internal surfaces of the materials. ➔ Water molecules are polar so they can become both highly adhesive to large organic molecules such as cellulose and cohesive to one another. DO | BLOCK 05191D 14  study ur worksheets too bffs REFERENCES Incipient plasmolysis - point at which protoplast has lost Notes from the discussion by Sir John Paul Domingo just enough water to pull slightly away from the wall. o Up to that point, the cell has lost very little water, so De La Salle University PowerPoint Presentation its volume change and osmotic potential change have not been great. o Because the pressure potential is now zero, the water potential equation is The cell has become plasmolyzed - If the cell has not reached equilibrium at the point of incipient plasmolysis, it continues to lose water, and the protoplast pulls completely away from the wall and shrinks. o Water potential continues to become more negative entirely because of the osmotic potential as solutes become more concentrated. IMBIBITION Description: a transport mechanism that does not require a semi-permeable membrane. o Results in swelling of material or enormous increase in volute. o Type of diffusion and unrelated to osmosis. o Initial step in the germination of seeds. o Water is attracted to and adheres to the internal surfaces of materials like cellulose, lignin, and starch (materials that have permanent suspension of fine particles). o E.g. absorption of water by seeds and dry wood. Molecules (cellulose and starch) - usually develop electrical charges when they are wet. o The charged molecules attract water molecules, which adhere to the internal surfaces of the materials. ➔ Water molecules are polar so they can become both highly adhesive to large organic molecules such as cellulose and cohesive to one another. DO | BLOCK 05191D 14  study ur worksheets too bffs REFERENCES Incipient plasmolysis - point at which protoplast has lost Notes from the discussion by Sir John Paul Domingo just enough water to pull slightly away from the wall. o Up to that point, the cell has lost very little water, so De La Salle University PowerPoint Presentation its volume change and osmotic potential change have not been great. o Because the pressure potential is now zero, the water potential equation is The cell has become plasmolyzed - If the cell has not reached equilibrium at the point of incipient plasmolysis, it continues to lose water, and the protoplast pulls completely away from the wall and shrinks. o Water potential continues to become more negative entirely because of the osmotic potential as solutes become more concentrated. IMBIBITION Description: a transport mechanism that does not require a semi-permeable membrane. o Results in swelling of material or enormous increase in volute. o Type of diffusion and unrelated to osmosis. o Initial step in the germination of seeds. o Water is attracted to and adheres to the internal surfaces of materials like cellulose, lignin, and starch (materials that have permanent suspension of fine particles). o E.g. absorption of water by seeds and dry wood. Molecules (cellulose and starch) - usually develop electrical charges when they are wet. o The charged molecules attract water molecules, which adhere to the internal surfaces of the materials. ➔ Water molecules are polar so they can become both highly adhesive to large organic molecules such as cellulose and cohesive to one another. DO | BLOCK 05191D 14  study ur worksheets too bffs REFERENCES Incipient plasmolysis - point at which protoplast has lost Notes from the discussion by Sir John Paul Domingo just enough water to pull slightly away from the wall. o Up to that point, the cell has lost very little water, so De La Salle University PowerPoint Presentation its volume change and osmotic potential change have not been great. o Because the pressure potential is now zero, the water potential equation is The cell has become plasmolyzed - If the cell has not reached equilibrium at the point of incipient plasmolysis, it continues to lose water, and the protoplast pulls completely away from the wall and shrinks. o Water potential continues to become more negative entirely because of the osmotic potential as solutes become more concentrated. IMBIBITION Description: a transport mechanism that does not require a semi-permeable membrane. o Results in swelling of material or enormous increase in volute. o Type of diffusion and unrelated to osmosis. o Initial step in the germination of seeds. o Water is attracted to and adheres to the internal surfaces of materials like cellulose, lignin, and starch (materials that have permanent suspension of fine particles). o E.g. absorption of water by seeds and dry wood. Molecules (cellulose and starch) - usually develop electrical charges when they are wet. o The charged molecules attract water molecules, which adhere to the internal surfaces of the materials. ➔ Water molecules are polar so they can become both highly adhesive to large organic molecules such as cellulose and cohesive to one another. DO | BLOCK 05191D 14 Pre-lab 1 : · IORGANIC + ORGANIC L Compounds Compromising LIFE · To BE CONSIDEred as living - organic · COMPOSED OF CARBON · SUPPLEmentAL MATERIALS : ~ H20 , O2 , minerals · SIMPLE UNIT OF LIFE CELL IS MADE a From : · Biomolecules (C- backbore) - CARBOHyDraTeS Y - PROTEINS VARIES IN ARRAGerenT S In CHO O LIPIDS & PRESENCE OF NITROSen & Phosphate · NUCLEIL ACID