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

  • Word count: 575
  • Level: GCSE
  • Subject: Science
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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

  • Word count: 3507
  • Level: GCSE
  • Subject: Science
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Yeast Investigation

Daniel Gillespie 11F Biology Coursework SC1 Introduction to yeast Yeast are unicellular fungi. It has been around for along time and has been involved in the making of bread, wine and other materials for man. Now yeast is used in many different industries for its fermentation properties. During this process in the industries the yeast is the waste product and is usually used for animal food or birdseeds. However the alcohol is the valuable product in the industry. Yeast has been a major material to man for a long time and is now a very expensive and profitable material for businesses and industries. The yeast respires to produce energy. When it does respire it produces and needs products and waste products, these are shown in the word equation below. To control this reaction the yeast has an enzyme; this enzyme is called zymase. Enzymes are used to control the speed and the rate of the respiration in the yeast, it changes the rate and speed by the environmental surroundings it is put in. glucose -----yeast---> ethanol + carbon dioxide + energy (210kj) C6H12O6 -----yeast---> 2C2H5OH + CO2 The reaction shown above is also called Fermentation. Fermentation is used in the brewing industry and the picture below shows how they ferment the sugar (glucose) in the yeast to make alcohol. Fermentation is the break down of sugars by using yeast

  • Word count: 4412
  • Level: GCSE
  • Subject: Science
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Why Does the Colour Leak Out of Cooked Beetroot?

Why Does the Colour Leak out of Cooked Beetroot? Aim: To investigate the effect of temperature on membrane structure. Hypothesis: I think that as the temperature increases the pigment contained within the cells will be released as the membrane breaks down. The pigments in beetroot cells are called betalin pigments. To extract the pigment, the cell membranes must be disrupted. This can be done by heat shock, by detergents or by solvents (e.g. ethanol or acidified methanol). Thin slices have a larger surface area and so leak more pigment; freezing the beetroot first bursts the cell membranes and kills the cells, thus allowing the pigment to be extracted much more quickly. When you heat a beetroot, you disrupt the cell membranes. A biological membrane is made of a so-called phospholipid bilayer. These are formed because the phospholipids that make it up have a polar "water-loving" (hydrophyllic) head and a "water-hating" (hydrophobic) tail. The tails pack together, exposing only the polar heads to the water. When you heat something you give it energy. Molecules start to spin and vibrate faster. The water will expand too. This will have a disruptive effect on any membrane in its way. To make things worse, lipids become more fluid as temperature goes up (so the membranes become more fragile. Proteins are formed of coiled and folded strings of amino-acids, held together by

  • Word count: 1408
  • Level: GCSE
  • Subject: Science
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Why does the colour leak out of cooked beetroot?

Why does the colour leak out of cooked beetroot? Hypothesis: Increasing the temperature of water baths surrounding sections of beetroot will cause the partially permeable membrane of the vacuole to become less stable, causing it to lose control of transport across, and allow betalains, red pigments, to pass out of the tonoplast and cause the beetroot to lose colour. When the distilled water containing the beetroot is tested, it will absorb much more light because the pigment leaked into it will cause it to become opaque. As we increase the temperature, so will the amount of pigments released increase, in a directly proportionate positive correlation. Aim: To find out if increasing the temperature of beetroot samples will affect the containment of pigment. Method: . We placed 8 slices of previously prepared 1cm³ beetroot into boiling tubes containing 5cm³ distilled water. 2. These we placed into water baths at temperatures of 0°C, 10°C, 20°C, 30°C, 40°C, 50°C and 6O°C, leaving them for thirty minutes to ensure that the beetroot and water reached the required temperature. For the water baths we used a selection of ice, salt, and boiling water to reach the desired temperature. 3. We then removed the beetroot sections from the boiling tubes, and shook the water and pigment solution to disperse the dye, and break any ice where appropriate. 4. From each boiling

  • Word count: 1430
  • Level: GCSE
  • Subject: Science
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