The Biological Structure of Water Water is a substance with the chemical formula H2O: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. Its structure enables it to carry out many important functions in the body. Water molecules are charged‚ with the oxygen atom being slightly negative and the hydrogen atoms being slightly positive. These opposite charges attract each other‚ forming hydrogen bonds. These are weak‚ long distance bonds that are very common and
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Process of Diffusion and its importance in living organisms Diffusion is the movement of molecules or ions down a concentration gradient i.e. from an area of high concentration to an area of low concentration. For a diffusion system to be efficient‚ it should have a large surface area so that high amount of substances can be exchanged at a time. It should also have a thin membrane and a continuous supply of substances‚ as a thin membrane means that the diffusion pathway would be short‚ and the continuous
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continuous exchange of water amongst reservoirs - "Reservoirs" constitute the hydrosphere - Reservoirs: oceans‚ lakes‚ rivers‚ glaciers‚ the atmosphere‚ living tissue - Hydrologic cycle is power by energy from the sun - causes: evaporation‚ transpiration‚ precipitation‚ run-off to the sea - Begins with evaporation of water from earth’s surface (especially oceans) - As moist air is lifted‚ it cools and the water
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8.3.1 1. Organisms are made of cells that have similar structural characteristics * Outline the historical development of the cell theory‚ in particular‚ the contributions of Robert Hooke and Robert Brown Date | Name | Event | 1590 | Janssens | World first two lens‚ compound microscope | 1655 | Robert Hooke | First person to use the word ‘cells’Observes these ‘cells’ in cork | 1600’s | Anton van Leeuwanhoek | Improvements in microscopesObserves muscle fibres and bacteria
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CORE ONE: MAINTAINING A BALANCE • IDENTIFY THE ROLE OF ENZYMES IN METABOLISM‚ DESCRIBE THEIR CHEMICAL COMPOSITION AND USE A SIMPLE MODEL TO DEMOSTRATE THEIR SPECIFITY ON SUBSTRATES. Enzymes are biological catalysts this means that they lower the energy required to start a chemical reaction within a cell but don’t get used up by that reaction. Every reaction and process in the metabolism of the cell is controlled by a specific enzyme. Enzymes are globular proteins whose shapes are specialised
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Trippple Award Specification (4BIO) Examination in 2012 Trippple Award Specification Key words are underlined in red. Practical work is printed in italics. Section 1: The nature and variety of living organisms Characteristics of living organisms include; M ovement R espitation S ensitivity G rowth R eproduction E xcretion N utrition In addition‚ all living organisms contain nucleic acids (DNA) and have the ability to control their internal conditions. Finally‚ all living
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Investigation into Succession in Sand Dunes. Scientific Knowledge: Succession is a long-term direction of change in the composition of a community‚ brought about by the organisms themselves. Primary succession occurs when a community develops on bare/uncolonised ground‚ which has never had vegetation growing on it. A good example of primary succession is that of succession on sand dunes. Secondary succession occurs on ground that has previously been colonised but is now available because
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Animal nutrition 6.3.1 Diet 6.3.2 Food supply 6.3.3 Human alimentary canal 6.3.4 Mechanical and physical digestion 6.3.5 Chemical digestion 6.3.6 Absorption 6.3.7 Assimilation 7. Transportation 7.1 Transport in plants 7.1.1 Water uptake 7.1.2 Transpiration 7.1.3 Translocation 7.2 Transport in humans 7.2.1 Heart 7.2.2 Arteries‚ veins and capillaries 7.2.3 Blood 8. Respiration 8.1 Aerobic respiration 8.2 Anaerobic respiration 8.3 Gas exchange 9. Excretion in humans 10. Coordination and response
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CLIMATE CHANGE: HOW THE HOMO SAPIENS HAVE CONTRIBUTED By Ernest Ebo Jackson TERM PAPER Climate change refers to change in average weather patterns and can be caused by both natural processes and human activities. In the past‚ the earth’s climate has been affected by natural factors such as changes in solar output and the discharge of volcanic ash. In fact‚ the planet has been through many periods of cooling and warming. The last period of major cooling ended about 10‚000 years ago.
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ground‚ and bodies of water is called the water cycle Water Cycle ● Precipitation cycles water from the atmosphere back to Earth: rain‚ snow‚ fog‚ sleet‚ ect. ● Evaporation cycles water from earth back to the atmosphere ● Transpiration is the release of water by plants 90% of water from land is returned back to the atmosphere this way. Carbon cycle ● Respiration releases co2 into thew atmosphere ● Combustion also releases co2 ● Decomposition releases
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