To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size.
Title: Investigating osmosis in potatoes Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Back Ground Information: Osmosis, transfer of a liquid solvent through a semi permeable membrane that does not allow dissolved solids (solutes) to pass. Osmosis refers only to transfer of solvent; transfer of solute is called dialysis. In either case the direction of transfer is from the area of higher concentration of the material transferred to the area of lower concentration. This spontaneous migration of a material from a region of higher concentration to a region of lower concentration is called diffusion. Plasmolysis is the separation of plant cell cytoplasm from the cell wall as a result of water loss. As moisture leaves the vacuole the total volume of the cytoplasm decreases while the cell itself, being rigid, hardly changes. Plasmolysis is unlikely to occur in the wild except in severe conditions. Plasmolysis is induced in the laboratory by immersing a plant cell in a strongly saline or sugary solution, so that water is lost or gained by osmosis. Further information on potato plant cells: Plant cells always have a strong cell wall surrounding them. When they take up water by osmosis they start to swell, but the cell wall prevents them from
Transpiration in Plants
Transpiration in Plants Hypothesis The rate of transpiration in a plant will increase in a windy environment. Justification Transpiration is the process of evaporation of water from plants. This process takes place in the leaves through the stomata. Transpiration is needed to transport the water and minerals ions from the roots in a plant to the leaves, stems and flowers to aid proper growth, Water is absorbed into the plant from the soil through the stem via the roots. It is absorbed by osmosis through the root hair, which supply a large surface area. The water ends up in the Xylem vessels at the centre of the root as a result of travelling through the cortex, endodermis and pericycle, normally through the appoplast pathway. The Xylem Vessels carry the water and mineral irons, which follow the flow of water, up the plant into the leaves. The water molecules form hydrogen bonds and stick together and travel up the plant. This effect is called capillary action. Once in the leaves the water evaporates through the Spongy mesophyll then diffuses through the stomata into the surroundings outside. This process is called transpiration. Plants control the transpiration process by opening and closing their stomata operated by the surrounding guard cells. The rate of transpiration will increase when it is windy because the wind will reduce the water concentration outside
Was the Medical Renaissance An Important Period In Medical History.
Was the Medical Renaissance An Important Period In Medical History The Renaissance period was an important time in the progress of medical history. Historians consider that the Middle Ages came to an end when many new and important ideas swept through Europe in the fifteenth and sixteenth centuries. This new period was then known ad the Renaissance. Many people of the time believed that great progress was being made in many fields because the love of knowledge had been re-born. The Renaissance was an important period because discoveries about anatomy were being made. This was a period of time in which many dramatic changes were taking place in the study of anatomy. The single most important figure in this great change is known by his Latin name, Vesalius. Vesalius was lucky enough to have received an excellent medical education and by the time he became a professor at the great Italian medical university, he was only twenty-three years of age. He had access to a regular supply of dead bodies for dissection which helped his study even more. As he carried out more and more dissections he began to have his first doubts about Galen and he concluded that Galen had only carried out dissections on animals. He noticed things such as the human lower jaw was different from Galen's description. Vesalius also wrote a comprehensive book about human anatomy. The development of the
Water is said to have unique properties. Explain what these are and show in what ways these properties are so important to life.
Water is said to have unique properties. Explain what these are and show in what ways these properties are so important to life. Water has many properties which makes it unique to all other lquids. It is one of the most important substances and even make up 80% of the body and 2/3 of the world. Many of the physical and chemical properties that make water so unique is due to its structure. Water is composed of one oxygen atom and two hydrogen atoms. Each hydrogen atom is covalently bonded to the oxygen. Oxygen also has two unshared pairs of electrons which has strong repulsion forces pushing the hydrogens further away. (see diagram 1) The bond angle between these hydrogen bonds is 105. This arrangement results in a polar molecule. This is due to the fact that there is a net negative charge toward the oxygen end of the molecule due to the unshared pairs of electrons and a net positive charge at the hydrogen end. The water molecle is therefore attracted to the opposite side of another water molecule, with each oxygen being able to attract two nearby hydrogen atoms. (see diagram2). Hydrogen Bonding is strong enough to keep water liquid at ordinary temperatures; its low molecular weight would normally tend to make it a gas at such temperatures. Diagram 1 Diagram 2 A water molecule Water as a universal solvent Water is unique in that it dissolves more substances than
What Affects The Rate Of Photosynthesis?
What Affects The Rate Of Photosynthesis? Aim: To investigate the factors that, affect the rate of photosynthesis. Planning: I will get some pondweed and place and place it in a beaker with some water and sodium hydrogen carbonate. Then I will shine a lamp on the pondweed and when it starts to release bubbles, I will start to count the bubbles. Then I will adjust the lamp to distances of 5 cm, 10 cm, 20 cm and 30 cm and try to get different results. Introduction: The experiments in this topic tells us that plants need carbon dioxide, water, light and chlorophyll in order to make food for themselves; and starch and oxygen are produced. Carbon dioxide and water are raw materials of photosynthesis. They react in some way to produce starch and oxygen, the products. We now know that this is not a simple reaction, but takes place in a series of steps. The reaction needs energy, and this comes from the light. The chlorophyll enables the plant to use light energy this way. Light and energy are therefore essential helpers in the process. Although starch is made in the end, it is not the first substance to be formed. Glucose is formed first and then turned into starch. Photosynthesis is therefore a complicated process. However is usually summed up by a simple equation. Light + chlorophyll 6CO2 + 6H2O ⇛ C6H12O6 + 6O2 Carbon + Water
Urban Myth.
Urban Myth It was an early Sunday morning and the sun was out yet the birds were silent and there wasn't a living creature for miles. The red-hot sun beamed down on the ground, scorching the asphalt. Stillness, stillness and silence, suddenly a red, fierce, Ferrari came roaring down the tarmac, with music pumped to the max and foot firmly on the pedal, leaving a trail of dust in its path. Behind the wheel, was a young, beautiful lady with not a worry in the world. Her mobile rang, she was unable to find her mobile she reached into the glove compartment and kept her eyes firmly on the road. With one hand firmly on the steering wheel and one hand in the glove compartment she searched for her mobile. Finally she found something that felt like her mobile and she grabbed it. It was trapped though. She looked down at the glove compartment to see why it was jammed. She realised the mobile is wedged between her CD changer and tracking system. In the process of trying to drag it out she took her eyes off the road, not seeing that there was a sharp bend up ahead. "Got it!" she declares, with her hands up in the air, in the process she spins the steering wheel to the right. The car jerks violently to the right, she hits her head on the window and grabs hold of the steering wheel. She hears tires screeching, she looked up and sees a humongous truck heading straight for her, she glanced
What is the biological significance of water?
What is the biological significance of water Water is the only substance that occurs as a gas, liquid, and solid within the temperature range found at the earth's surface. Bio. Significance: As a gaseous component of the atmosphere, water helps transfer heat from warm low latitudes to cold high latitudes. As a liquid, water runs across the continents dissolving minerals from the rocks and carrying them to the oceans. It is this form of water that accounts for over 85% of the mass of most marine organisms and serves as the medium in which the chemical reactions that support life occur. Liquid water also contributes to heat transfer through ocean currents. Solid water (Ice), during the winter season at the higher latitudes increases surface salinity and makes possible the sinking of dense surface water. This water is the only source of oxygen for the deep ocean. SOLVENT PROPERTY. Water can dissolve more substances than any other common liquid. Bio. Significance. Ocean water carries dissolved within it the nutrients and oxygen required by marine organisms. This has produced the "saltiness" of the ocean. HEAT CAPACITY. The quanity of heat required to change the temperature of 1 gram of a substance 1 Degree Celsius. Water has the highest heat capacity of all common liquids. Bio. Significance. It is this property that makes water an important moderator of
What factors affect the rate of photosynthesis?
What factors affect the rate of photosynthesis? Photosynthesis is the reaction that is used in plants to produce simple sugars. The equation is: Carbon dioxide + Water Glucose + Oxygen Or 6CO + 6H 0 C H 0 + 6O Photosynthesis takes place in the leaves of the plants. It needs sunlight and chlorophyll to produce food. Without sunlight and chlorophyll plants will not be able to photosynthesise as the energy from the sunlight is needed and to extract it chlorophyll in the chloroplasts is used. The raw materials needed for photosynthesis are carbon dioxide and water which together in the presence of sunlight and chlorophyll produces glucose and oxygen. The sunlight needed for photosynthesis is trapped by the chlorophyll in the chloroplasts of a leaf. To allow maximum surface area of chlorophyll exposed to light the chloroplasts inside the palisade cells are in tight 'pancake' shaped stacks so that there will be more chlorophyll available to absorb light. A chloroplast consists of a double membrane, stroma (dense fluid) and thylakoids (disc like sacs). The chlorophyll is situated on the thylakoids in the chloroplasts so that it is exposed to more sunlight. Leaves of a plant are green as the chlorophyll absorbs all wavelengths of light except green and so reflect it. There are many types of chlorophyll found in different plants but A
William Harvey.
William Harvey William Harvey was born in 1578, around the time of Shakespeare, and grew to receive a fine education and a degree at Cambridge at the age of 20, and then went on to study in Italy at Padua University, the most prestigious medical university in Europe at that time. He graduated with honours and returned to England in 1602 to return to Cambridge and receive another medical degree from Cambridge. It was then that he decided he had enough education and began to formally practise medicine. Harvey's true passion was circulation. At the time, common belief was that food was absorbed into the liver and then changed into blood, which was used as a fuel for the body. Because of Harvey's studies of the human body involving dissection, he knew that this could not have been true, so he threw himself into working on how the circulatory system worked. In 1928 he published An Anatomical Study of the Motion of the Heart and of the Blood in Animals. In this, he gave explanation to how the heart pumped blood around the body and how it was recirculated. This came to be very controversial due to their unconventional theories, but nonetheless, Harvey later became recognised as a genius of his day. He was even doctor to king Charles 1st. In Harvey's first steps at studying the circulatory system, he deduced that the heart was in fact a muscle, and that it did pump blood around the
Wuthering heights
Thesis: Wuthering heights and the importance of the traditional ghost story 'My fingers closed on the fingers of a little, ice-cold hand! The intense horror of nightmare came over me: I tried to draw back my arm, but the hand clung to it' (Page 20) In this extract Lockwood thought he had a dream, he remembers that he 'turned and dozed' and dreamt again, but the above extract shows that this was different from any other dream, it is much more realistic and increasingly frightening. This leads the reader to believe that this really is not a dream and that a supernatural being is causing this entire disturbance. The importance that this has to the novel is that it adds an element of excitement and mystery to the novel, rather than Lockwood just having a dream about a ghost by the end of the extract, they believe that their really was on there. What makes this part of the novel all the more stirring is the fact that there is evidence that this really was a ghost at Lockwood's window. For instance Lockwood says that that name of the ghost was 'Catherine Linton': '(Why did I think of Linton? I had read Earnshaw twenty times for Linton)' (Page20) This is to say that in any dream one would not expect to dream about someone they had never met before, and they would expect for their dreams to be a collaged combination of all the things that had happened to them. In this particular
