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31 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Identify and describe the macro nutrients |
Protein Source meat, fish, eggs, pulses(peas, beans, lentils)
Function >growth and repair >Formation of enzymes?some hormones >transport
*Biuret test used to show its presence
Carbohydrates Source sugar, biscuits, cakes, bread, pasta
Function >energy source >energy storage e.g glycogen
*Iodine used to test for starch *Benedict solution used to test for reducing sugars
Lipids Source butter, pork, oils
Functions >energy source >protects against knocks >solvent for vitamin A
* Ethanol tests identifies lipids in foods
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Protein Carbohydrates Lipids
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Identify and describe the vitamins |
A source milk, butter, liver use making a chemical in the eye Deficiency Nightblindness B source yeast extract, liver Use cell respiration deficiency Beri-Beri C source citrus fruits use healing of wounds connective tissue formation deficiency scurvy-bleeding gums, tooth loss D source made in the skin in sunlight helps bones absorb calcium and phosphorous deficiency Rickets-weakened bones poor teeth |
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Identify and describe the minerals |
Iron Source Liver, eggs, green vegetables Use production of haemoglobin in red blood cells deficiency Anemia- Reduction in red blood cells Calcium Source Cheese,milk, fish Use Making bones and teeth deficiency rickets |
Iron Calcium |
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Functions of water |
>cooling in the skin >a solvent used in the transport of substance around the body >support in plants >used in chemical reactions i.e hydrolysis reactions for example when water is added to sucrose it is broken down into glucose and fructose |
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Dietary fibre |
>found in plant material >made up of cellulose from the walls of plant cells >provides bulk to faeces in order to stimulate peristalsis and so preventing constipation >regular removal of faeces reduces the risk of inflammation of the colon and bowel cancer |
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BMI |
weight BMI = ---------- Height 2
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Tooth decay |
Too much sugar can result in tooth decay. This is because the bacteria in our mouths turn the sugar into acids which attack the enamel of our teeth |
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Plaque |
A mixture of saliva, food and bacteria which froms naturally on the teeth. Bacteria in the plaque produces acids and toxins from the food, particularly if the food is sugary. |
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Dental caries |
caused by the acid dissolving the enamel and dentine of the tooth which leads to a cavity |
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Peridontal disease |
caused by the bacterial toxins. cause inflammation at the point where the gum and tooth meet. |
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Enzyme |
a biological catalyst that speeds up a chemical reaction the breakdown of large food molecules into smaller soluble molecules through hydrolysis is catalyzed by enzymes a protein which catalyses a specific reaction |
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Properties of enzymes |
>reduce the energy needed formolecues to react together >have an active site which fits the reactants of the reaction it catalyses >are unchanged at the end of the reaction it speeds up |
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Factors affecting enzymes |
inhibitors temperature active site is destroyed above optimum temperature pH affects shape of enzyme Enzyme/substrate concentration |
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Digestion |
mechanical and chemical digestion of food |
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Egestion |
The removal of undigested food from the anus |
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Mastication |
the breakdown of food into smaller pieces by the teeth |
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Bolus |
ball of food formed by the tongue |
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Saliva |
ph of about 7.0 (neutral) secreted from the salivary gland and is a mixture of water, mucus and salivary amalyse the water and mucus soften the food while the salivary amylase begins to digest starch by hydrolysis eventually producing glucose molecules |
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Hydrochloric acid |
helps breakdown food stimulates a drop in the pH of the stomach to about 1.5 (acidic) as a result many bacteria taken in with food are killed the breakdown of starch to maltose stops and an ideal environment for stomach enzymes is produced. |
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Gastric juices
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consists of mucus, hydrochloric acid and pepsin. Digestion of proteins begin in the stomach as the long chains of proteins are broken down by the protease(enzyme), pepsin into smaller chains of amino acids(polypeptides) |
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Stomach |
muscular bag which stores food for a short time and mixes food with acidic digestive juices to form chyme |
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Sphincter musles |
retain food in the somach |
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Duodenum |
first part of the small intestine where the chyme is mixed with secretions from the liver(bile) and pancreas(pancraetic juice). |
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Bile |
produced by the liver and stored in the gall bladder is alkaline and contributes to the rise in ph to about 8.0 in the duodenum emulsifies lipids, i.e. changes large lipid drops into many smaller lipid droplets by reducing their surface tension(emulsification) makes it easier for lipase to break down lipid molecules |
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Pancreatic juices |
is produced by the pancreas is alkaline contains enzymes >amylase which converts remaining starch to maltose >proteases e.g trypsin which covert polypeptides to peptides >lipases which cover emulsified lipids to glycerol and fatty acids |
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illeum |
longest part of the small intestine, where digested food is absorbed into the blood and lymphatic system Digestion is completed here >maltase converts maltose to glucose >sucrase converts sucrose to glucose and fructose >lactase converts lactose to glucose and galactose >peptidases convert peptides into individual amino acids |
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Absorption |
Movement of soluble food molecules from the intestine into the blood and lymph |
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Assimilation |
Use of food molecules in the body e.g making proteins. |
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Villi in the small intestine |
>villus large surface area for absorption >blood capillaries very extensive so much absorption >mitochondria supplies atp fro the active uptake of substances >epithelium one cell thick therefore molecules can move across into the blood sysytem |
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Large intestine |
appendix and caecum have no specific function colon >absorbs water so that faeces become drier >inhabited by mutualistic bacteria which digest the remaining food and prevent other harmful bacteria from growing and causing discomfort or disease Rectum the dry faeces are stored in the rectum and periodically released |
appendix caecum colon rectum |
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Liver |
>control of blood sugar concentration >removal of the nitrogen containing part of excess amino acids(deamination) >production of urea >production of blood proteins including fibrinogen for use in blood clotting >important in temperature regulation >destruction of old red blood cells >production of bile >breakdown of toxins >storage of vitamins |
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