Nutrition Assignment

A. Outline what is meant by a 'balanced diet' and explain why each component is required. 'A balanced diet is important to maintain health and a sensible body weight. No single food will provide all the essential nutrients that the body needs to be healthy and function efficiently. The nutritional value of a person's diet depends on the overall mixture, or balance, of food that is eaten over a period of time, as well as on the needs of the individual. A diet which includes a variety of different foods is most likely to provide all the essential nutrients.' (www.igd.com) The balanced diet must contain the following elements in the correct proportions: . Carbohydrates, 2. Protein, 3. Fats and oils, 4. Vitamins: A, B1, B2 etc up to B12, C, D, E 5. Mineral salts 6. Fibre (Roughage) 7. Water Each of the above are need to make the body work and there is negative affect to our bodies if we do get the correct amount or do with out them altogether. The following are the uses and what will happen if we do not the appropriate levels in our diet: . Carbohydrates: these provide a source of energy, if too much is consumed and you will gain excess weight and if too little is consumed you it will make you feel tired and lethargic. 2. Proteins: these provide a source of materials for growth and repair too much protein in the diet and you will gain weight and might make a lot

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  • Level: AS and A Level
  • Subject: Science
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Effect of Temperature on Rate of Hydrolysation of Pineapples

Investigation to determine whether temperature affects the rate of hydrolysation of bromelain enzymes within pineapples when placed within protein substrates Aim: To investigate the effects of increasing temperatures on pineapples, which contain the enzyme bromelain, and observe the affect on the rate of hydrolysation when placed within gelatine. Scientific background: Gelatine is a common protein used in the manufacture of jelly. It consists mainly of collagen which is a fibrous protein present in all animals. The structure of a protein is made up of a numerous amount of amino acids joined together by the process of condensation as shown in the diagram below. Figure 1.0 Proteins are polymers of amino acids, and these polymers or polypeptides are made up of amino acids in a specific sequence which determines the proteins function. This is known as the primary structure of a protein. The basic structure of these amino acids is shown below. The R groups of the amino acids interact with each other, altering the chain to twist and fold into a three dimensional shape. The length of chains can coil into alpha helices or beta pleated sheets and this is known as the secondary structure. The polypeptide chain then folds to produce a specific 3D shape which forms the tertiary structure. These proteins, as mentioned are made throughout the formation of peptide bonds between

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  • Level: AS and A Level
  • Subject: Science
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How ATP is produced in both the chloroplast and mitochondria.

How ATP is produced in both the chloroplast and mitochondria Introduction: Living organisms use it as a free-energy donor to supply free energy for three major purposes: muscular contraction and other cellular movements, the active transport of molecules and ions, and the synthesis of proteins. ATP is not a long-term storage form of energy - is an immediate donor of energy. Most ATP is consumed within a minute ofbeing produced. The turnover of ATP is very high . ATP Generation in Mitochondria and Chloroplasts: ATP generation is driven by the electrochemical gradient of protons (the proton motive force) that exists in both mitochondria and chloroplasts. However, the mechanisms in each organelle are different when compared in detail, as will be considered later. In both chloroplasts and mitochondria the driving force behind ATP synthesis is the proton motive force that exists between two cellular compartments. This force is produced by the electrochemical gradient for H+ across the membrane dividing the two compartments, which is impermeable to protons. The proton motive force depends on the difference in pH (i.e. the concentration of H+) between these two compartments, and the membrane potential of the membrane separating them. In one compartment the concentration of H+ and of positive charge is high, in the other the concentration of H+ is low and the membrane

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  • Level: AS and A Level
  • Subject: Science
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Effect of Anaerobic Respiration On Yeast

The Effect of Temperature on the Anaerobic Respiration of Yeast Aim: To investigate the effect of temperature on the rate of respiration in a suspension of yeast Saccharomyces cerevisiae. Background Knowledge: Yeasts are a form of eukaryotic microorganisms classified in the kingdom Fungi, with approximately 1,500 species known. They reproduce asexually by budding mainly, although some species reproduce by binary fission. They are unicellular, although some species with yeast forms may become multicellular due to way in which they normally reproduce. Typically the size of a yeast cell is approximately 3-4 µm in diameter but this can vary greatly depending on the species. The yeast species Saccharomyces cerevisiae has been used in baking and fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is the most thoroughly researched eukaryotic microorganism. Researchers can use it to gather information into the biology of the eukaryotic cell and human biology. These microbes are thought to be one of the first domesticated organisms. People have used yeast for fermentation and baking throughout history. Archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeasted bread, as well as drawings of 4,000-year-old bakeries and breweries. It has many

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  • Level: AS and A Level
  • Subject: Science
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the effect of ethanol on the rate of anaerobic respiration

Skill P: The effect of ethanol on the rate of anaerobic respiration of sucrose by yeast Aim: This is an experiment to investigate at which rates the different sugar-yeast-ethanol-mixtures move to the end of the 1mm capillary tube using five different ethanol concentrations. Background theory: Saccharomyces cerevisiae is a species of budding yeast. Yeast is used in bread making and brewing. In brewing yeasts ferment fruit or grain to produce alcoholic drinks. In bread making yeasts produce carbon dioxide which helps the bread to rise. The alcohol evaporates during baking. It is believed that yeast was originally isolated from the skin of grapes. Yeast contains many enzymes including sucrase which breaks down sucrose into glucose and fructose. The official name for sucrase is beta-fructofuranosidase (1, 11). Carbohydrates are a group of substances that are important in many biological processes. They provide energy-rich nutrients to organisms and are used to build up their body structures; all carbohydrates contain hydrogen, carbon and oxygen. The carbohydrate sucrose is a disaccharide of one glucose sugar and one fructose sugar joined by a glycosidic bond. Glucose and fructose are both monosaccharides, and structural isomers and both respire to give off the same products (2). When oxygen is not available, oxidative phosphorylation and the Krebs cycle cannot take place.

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  • Level: AS and A Level
  • Subject: Science
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Discuss the Advantages and Disadvantages of being Ectothermic and Endothermic for Vertebrates.

Discuss the Advantages and Disadvantages of being Ectothermic and Endothermic for Vertebrates. Vertebrates can be found all over the world, from the freezing poles to the hot deserts. The normal air temperature in these regions varies from -40?C to 50?C respectively. The majority of living organisms exist within confined limits of temperature, (approximately 10-35?C), but various organisms show adaptations enabling them to exploit geographical areas at both extremes of temperature. Temperature indicates the amount of heat energy in a system, and is a major factor determining the rate of chemical reactions. The most important reactions which are inhibited by inappropriate temperature are those that are catalysed by enzymes. Below freezing point, cells may freeze, and the cell structure destroyed by formation of ice crystals. Above 45?C enzymes usually become denatured, ceasing to function; in both of these cases, the organism dies. Therefore, if vertebrates did not regulate their body temperature they would be unable to survive outside a narrow range of temperatures. All animals derive heat from two sources: the external environment and from the release of chemical energy within their cells. The extent to which animals are able to generate and conserve this heat depends upon physiological mechanisms associated with their phylogenetic position. The possible evolution

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  • Level: AS and A Level
  • Subject: Science
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Zonation on the Rocky Shore at Starfish Bay.

Zonation on the Rocky Shore at Starfish Bay Attachments: (i) Profile of the Belt Transect, showing how vertical height changes with the distance along the transect (ii) Kite Diagram, showing the mean density of organisms at each 2m interval using data from all groups in the class (iii) Sketch Map of Starfish Bay (iv) Map of Hong Kong showing location of Starfish Bay (v) Data Record Sheet for the Rocky Shore at Starfish Bay (August 2003) (vi) Data Record Sheet for the Rocky Shore at Starfish Bay of the other two groups in class (vii) Notes made on the field trip to Starfish Bay (viii) Identification Chart showing Images of Organisms on the Rocky Shore (ix) Tide Table for 28th August, 2003 Zonation on the Rocky Shore at Starfish Bay Date of Investigation: 28th August, 2003 Working Partner(s): Drink, Ivan and Devin Introduction The research question explores into the zonation pattern on the rocky shore at Starfish Bay. Such investigation is useful as it provides information about whether the rocky shore ecosystem is divided into distinct zones, and acts as an indicator of the health of the environment. For example, if results of continuous investigations are anomalous, negative changes have most likely occurred. This signalises that perhaps more measures are needed for conserving Hong Kong's environment. My hypothesis is that the data collected will show evidence

  • Word count: 3456
  • Level: AS and A Level
  • Subject: Science
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Current Research in Nuclear Fusion Power and Its Place in Future Electricity Production.

Current Research in Nuclear Fusion Power and Its Place in Future Electricity Production Introduction Nuclear fusion is a process where two lighter atomic nuclei fuse, forming a heavier nucleus and releasing energy. The type of nuclear fusion currently being researched most vigorously in the context of forming a future source of power is the fusion of two isotopes of hydrogen - deuterium and tritium, forming helium and a neutron and releasing large amounts of energy. = Neutron = Proton Deuterium Nucleus Neutron (+14.1 MeV) Tritium Nucleus Helium Nucleus (+3.5 MeV) Figure 1 This can be described by the equation H + H ==> He + n, yielding 17.6 MeV per fusion. Another fusion reaction which is possible is the fusion of two deuterium nuclei, though this yields less energy and is not generally being pursued as a source of power in future reactors. It is described by the equation H + H ==> He + n, yielding 3.3 MeV per fusion. A central concept in understanding the origin of this extra energy is the equivalence of mass and energy. The strong nuclear force binds together protons and neutrons in the nucleus, it is very strong over short distances hence it overcomes the electromagnetic repulsion of protons in the nucleus. The energy that is required to hold to hold the nucleus together can be thought of as adding to its mass.

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  • Level: AS and A Level
  • Subject: Science
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Feeding The Third World

Feeding The Third World Millions of people today, despite technological advances enabling fish and meat production and crop yields to soar, are still living in hunger. It is estimated that nearly 30% of the world's population suffer from some form of malnutrition, and the majority of these people live in Developing Countries. Intensive and Subsistence Farming both present possible solutions to dealing with world hunger and ending the suffering of the Third World. Intensive Agriculture, also known as Factory or Battery Farming, involves land being farmed in order to achieve the greatest yield possible with the use of inorganic fertilisers and pesticides because it is used to supply large companies and distributors. Monoculture Intensive Farming focuses on Monoculture; large areas where the same crop is grown on the same land year after year. Farmers generally specialise in growing one to three types of crops, with land being cleared once a year before the crop is planted. Factory farming also concentrates on one form of husbandry, e.g. dairy, cattle, or pig breeding. By doing so; Farmers make better use of their equipment. Organisations such as supermarkets benefit by having fewer farms to negotiate purchases with. These points mean that intensive farms are on the whole economical and resourceful. In monoculture areas, most hedges, walls and fences are removed

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  • Level: AS and A Level
  • Subject: Science
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Coursework: Response to Light in Blowfly Larvae.

Florence Annan Candidate number: 5900 Centre number: 48255 U6A Miller/Williams Question: Response to Light in Blowfly Larvae. Null Hypothesis: Blowfly larvae have no response to light. They have no preference ion moving towards a light source or away from a light source. This will be shown at the end of the experiment by there being a 50% even spread in either tray. Hypothesis: Blowfly larvae have a reaction to light. A larger proportion will move away from the light during the experiment than will move towards it. Reasoning: Almost all larvae react to the light and attempt to move away from it, as due to their large surface area and their thin epidermis they risk drying out. The larvae have photoreceptor cells. These are specialized cells, which consist of two molecules in a membrane, opsin, and a light sensitive protein, which surrounds the chromophore, which is a pigment that is used to detect colours. Clusters of these cells allow the maggot to detect only a very basic sense of the direction and intensity of light- enough to distinguish whether they are heading towards an area of light or away from one, but not enough to discriminate an object from its surroundings. Therefore, the larvae will know that they are moving away from an area containing more light and so will try to move in that direction in order to reduce their risk of drying out. They also risk being

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  • Level: AS and A Level
  • Subject: Science
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