Investigate a factor which can affect the process of osmosis in a living plant tissue
Meetal Odedra 11V Biology coursework Investigate a factor which can affect the process of osmosis in a living plant tissue Planning For this coursework investigation I will be investigating factors that affect the process of osmosis in a living plant cell, but mainly focusing on one factor I have chosen. In order to do so, I have conducted some background research on osmosis to help me understand the investigation in hand. Background Scientific Research (Using D.G. Mackean's GCSE Biology textbook) Osmosis is defined as the movement of water molecules from a high concentration of water (potential) to a lower concentration of water (potential) down a concentration gradient, through a partially permeable membrane. When a substance such as sugar dissolves in water, it reduces the concentration of the water molecules because the sugar molecules attract some of the water molecules and stop them moving freely. Osmosis can be explained with the help of the diagram below: The diagram shows that the sugar molecules on the right have attracted half of the water molecules. There are now more free water molecules on the left than on the right so water molecules will diffuse more rapidly from left to right across the partially permeable membrane, than from right to left. This is because the net movement of the water molecules move from the high concentration of water
Mr Chips: Investigation to find an isotonic solution for potatoes
Mr Chips: Investigation to find an isotonic solution for potatoes Introduction Investigation aimed to find out the amount of grams of salt solute needed to create an isotonic solution to prevent osmosis in fresh cut potato chips. Osmosis is the movement of water molecules through a selectively-permeable membrane down a water potential gradient. More specifically, it is the movement of water across a selectively permeable membrane from an area of high water potential (low solute concentration) to an area of low water potential (high solute concentration). The water molecules will continue to move through the semi-permeable membrane until both sides have reached a state of equilibrium. Isotonic solution is a solution in which its solute concentration is the same as the solute concentration of another solution with which it is compared In plant cells when water moves into the vacuole it increases in size and pushes the cell membrane against the cell wall, this causes the cellulose cell wall to stretch slightly and when it can stretch no further it becomes taut and firm. The pressure inside the cell rises and eventually the internal pressure of the cell is so high that no more water can enter the cell. This liquid or hydrostatic pressure works against osmosis. At this point the cell wall prevents the cell from bursting and is said to be fully turgid. Turgidity is very
The Importance and Biological Functions of Carbohydrates.
The Importance and Biological Functions of Carbohydrates. Carbohydrates have many functions. This essay will look at some of them and also what carbohydrates are constructed of. A Carbohydrate molecule contains Carbon, Hydrogen and Oxygen. There are twice as many Hydrogens as there are Oxygens, the same proportion as water. Carbohydrates have the general formula of C (H O) Carbohydrates can be divided into three main types. These are monosaccharides (single sugar units), disaccharides (two sugar units) and polysaccharides (many sugar units). Different monosaccharides contain different numbers of carbon atoms. Trioses contain three, pentoses contain five and hexoses six. Carbohydrates have many different functions and come in many different forms. Ribose and Deoxyribose are both pentose monosaccharides and are found in RNA and DNA. Glucose and Fructose are both hexose monosaccharides. Glucose is an important source of energy in respiration and Fructose is found in fruits. Sucrose is a disaccharide formed from Glucose and fructose. It is the form in which carbohydrates are transported in plants. Maltose is a disaccharide of glucose and is formed from the digestion of starch. The carbohydrate in milk is lactose and it is formed from Glucose and galactose. Important polysaccharides include Starch, Glycogen and Cellulose. They are all made up from Glucose but have different
Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis
COURSEWORK INVESTIGATION Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis Tahir Aziz CONTENTS > Plan > Outline method > Key variables > Risk assessment > Preliminary results > Method > Results of control experiments > Results > Conclusions > Main trends and patterns > Explanation of results > Experimental limitations Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis Abstract The average adult has about five litres of blood living inside of their body, coursing through their vessels, delivering essential elements, and removing harmful wastes. Without blood, the human body would stop working. Blood is the fluid of life, transporting oxygen from the lungs to body tissue and carbon dioxide from body tissue to the lungs. Blood is the fluid of growth, transporting nourishment from digestion and hormones from glands throughout the body. Blood is the fluid of health, transporting disease fighting substances to the tissue and waste to the kidneys. Because it contains living cells, blood is alive. Red blood cells and white blood cells are responsible for nourishing and cleansing the body. Since the cells are alive, they too need nourishment. Vitamins and Minerals keep the blood healthy. The blood cells have a definite life cycle, just as all living organisms do. Approximately 55 percent of blood is plasma, a straw-collared clear
Determining the Water Potential of Sweet Potato Tissue
Determining the Water Potential of Sweet Potato Tissue Introduction The aim of this experiment is to determine the water potential of sweet potato tissue using osmosis. This can be achieved by placing the samples inside different molarities of sucrose solution and work out the percentage change in mass and then with the aid of a conversion graph convert molarity to water potential (kPa), without the weight of the sweet potatoes being a factor. Background Knowledge In mature plant cells, the fluid filled vacuole occupies most of the cell volume therefore in order to determine the water potential of the sample I would need to work out the water potential of this fluid inside the cell. Substances can pass in and out of cells by four different processes: * Diffusion * Osmosis * Active transport * Endocytosis & exocytosis All these processes involve substances passing through the cell membrane of the cell. In this investigation, I only need to consider osmosis. OSMOSIS is the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. This is a colligative property i.e. dependent on the concentration of particles in a solution. The water molecules involved always move down a ? gradient. It happens because of the natural kinetic energy possessed by the particles, which makes them move
Transport across plasma membranes
Transport across plasma membranes In this essay I will discuss and explain the transport across plasma membranes, to do this, I shall refer to osmosis, diffusion, facilitated diffusion, active transport and finally, exocytosis and endocytosis. Like all other cellular membranes, the plasma membrane consists of both lipids and proteins. The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments. In the case of the plasma membrane, these compartments are the inside and the outside of the cell. Proteins embedded within the phospholipid bilayer carry out the specific functions of the plasma membrane, including selective transport of molecules. The diagram opposite shows the fluid The plasma membrane is a selectively permeable barrier between the cell and the extracellular environment. Its permeability properties ensure that essential molecules such as glucose, amino acids, and lipids are able to readily enter the cell, leaving larger substances remaining in the cell. This allows the cell to maintain a constant internal environment. This is more commonly known as osmosis; the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. It is a physical, hydrophilic process in which a solvent moves, across a semi-permeable membrane
Human Reproductive System
The Human Reproductive System Structures of the male reproductive system Bulb of penis The bulb of penis is the expanded posterior part of the corpus spongiosum of the penis. It lies in the interval between the crura of the penis. It contains slightly dilated and angulated portion of the urethra. Bulbourethral (Cowper's) gland The bulbourethral gland is pea-sized structures located on the sides of the urethra below the prostate gland. It produces a clear, slippery fluid that empties directly into the urethra. These fluids lubricate the urethra and neutralises any acidity that may be present due to residual drops of urine in the urethra. Corona The corona is a rounded projecting border that forms the circumference of the base of the glans. It is located behind the penis and overhangs a deep retroglancular sulcus Corpora cavernosum penis The corpus cavernosum penis is one of the pair of sponge-like regions of erectile tissue in the penis. It contains irregular spaces which are filled with blood during erection. These spaces are lined by endothelium and separated by connective tissue septa. Corpus spongiosum penis The corpus spongiosum penis is the median column of erectile tissue located between and ventral to the two corpora cavernosa penis. Posteriorly It expands into the bulb of penis and terminates as enlarged glans penis anteriorly. Ductus (vas) deferens The
To investigate the effect of trampling on the frequency of creeping moss - Plan
Aim: To investigate the effect of trampling on the frequency of creeping moss Hypothesis: As you move away from the footpath the frequency of creeping moss increases. Scientific name: Pseudoscleropodium purum Justification of hypothesis: As the distance from the path increases, the frequency of creeping moss increases. This is because people tread on this area and therefore make the abundance of creeping moss lower. Box Hill had "1 million visits a year" Emma Peasland, senior tutor, FSC, 24/01/07 (personal communication). It has been around and popular for over 20 years. This means the footpath has been trampled on by a possible 200 million people. If the soil has been trampled on by a possible 200 million people then the footpath is likely to be compressed and the roots of the creeping moss are forced to be of low height and therefore be weak and unstable. Because they are unstable, they will easily be ripped out of their roots. "Soils that are deep, well-drained, and have desirable texture and structure are suitable for the production of most garden or landscape plants. Deep soils can hold more plant nutrients and water than can shallow soils with similar textures. Depth of soil and its capacity for nutrients and water frequently determine the yield from a crop, particularly annual crops that are grown with little or no irrigation. Plants growing on shallow soils
Difference in number of Stomata in different leaves
Biology Coursework An investigation will be carried out to see how the numbers of stomata differ in different plant species. Stomata are tiny openings found on the underside of the plant leaf. [1] The pore is formed by a pair of cells called 'Guard Cells'. Guard cells control the opening of the stomata. These pores on the underside of the plant leaf allow carbon dioxide to enter. Carbon dioxide is used in photosynthesis. At the same time when the stomata are open Oxygen and water vapour escape from inside of the plant. Water vapour leaving the plant is called Transpiration. This occurs mostly in leaves of the plant but can be from the flower and the stem. Hypothesis The leaves of different plants and the sections of leaves will have different number of stomata. The amount of stomata on the plant leaf is dependant on the environment. The plants that are in temperate environment will have many more stomata than the plants that are in Tropical environments. Null Hypothesis There is no difference in the number of stomata in any plant leaf or any section of the plant. Any difference is purely due to chance I will investigate how to find out the different number of stomata in a plant leaf. Experiment Apparatus Nail Varnish Microscope Microscopic slide Lab coat Tape Plant leaf Step by Step - Get apparatus 2- Take a leaf from a plant and mark 3 sections, top,
Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL KNOWLEDGE
TABLE OF CONTENTS Biological Knowledge ... 3 Explanation ... 3 Types of solutions and its effects on plant cell ... 4 Factors affecting rates of osmosis ... 6 Outline Method ... 9 Apparatus ... 9 Materials ... 9 Risk Assessments ... 9 Precautions ... 9 Apparatus Diagrams ... 10 Factors to be controlled ... 11 Method ... 11 Calculations to be used ... 12 Predicted Results ... 12 Prior Test ... 13 Obtaining Evidence ... 16 Apparatus ... 16 Materials ... 16 Risk Assessments ... 16 Precautions ... 16 Method ... 17 Results obtained for Mass ... 18 Results obtained for Length ... 19 Analysis ... 21 Trends in the Bar charts ... 25 Scientific Explanation ... 25 Determination of molarity ... 28 How far I have reached my predicted results ... 30 Evaluation ... 32 Errors ... 32 Accuracy and reliability of my results ... 32 Extension work ... 33 Bibliography ... 33 INTRODUCTION Biology Coursework Aim: To find the molarity of potato tuber's cell sap. BIOLOGICAL KNOWLEDGE Osmosis is the diffusion of fluid through a semi-permeable membrane from a solution with a low solute concentration to a solution with a higher solute
