2629055
Descrição
FlashCards por Kate Kowalska, atualizado more than 1 year ago
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Criado por Kate Kowalska
mais de 9 anos atrás
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| Questão | Responda |
| What is a balanced diet? | A diet that provides the body with all it's nutritional needs in the right proportions on a daily basis. |
| What should a balance diet provide? | 1) sufficient energy 2) essential amino and fatty acids 3) micronutrients (vitamins/minerals) 4) dietary fibre (also know as roughage) 5) water. |
| What are macronutrients? How much do you need a day? | Carbohydrates, lipids, proteins. Required in large quantities (several grams a day). |
| What are micronutrients? How much do you need a day? | Vitamins and minerals. Required in small quantities ( 1mg or less per day). |
| What do we need carbohydrates for? | Energy source and some are building blocks (e.g. ribose in DNA). |
| What do we need protein for? | Essential amino acids: 1) structural components 2) metabolism (enzyme/hormones) 3) antibodies 4) plasma proteins |
| What do we need lipids for? | 1) Energy source 2) Membrane component 3) Essential fatty acids |
| What types of vitamins do we need? | Fat soluble and water soluble. |
| What is dietary fibre? What do we need it for? | Roughage that has no calorific content. This aids peristalsis (moving waste through the body). |
| What do we need water for? | 1) Acts as solvent 2) Metabolic reactions take place in solution 3) Transport medium 4) Coolant due to its high latent heat of vaporisation |
| What is the formula for BMI? | = body mass (kg)/ (height in m)^2 |
| What percentage over the recommended BMI are you classed as clinically obese? | >20% |
| What type of carbohydrate is preferable? Why? | Starches/complex carbohydrates. You have time to digest, slow release into blood. |
| What are the typical requirements of carbohydrates for... a) 18 year old male b) 18 year old female | a) 367g per day b) 281g per day |
| How much percentage of our energy comes from carbohydrates? | 57% |
| What type of lipids are essential? | Linoleic and linolenic fatty acids. |
| What are the typical requirements of lipids for... a) a 18 year old male b) a 18 year old female | a) 107g per day b) 82g per day |
| How much percentage of our energy comes from lipids? | 30% |
| What makes proteins different to other macronutrients? | Excess protein cannot be stored in the body. It is converted into urea and then excreted. |
| What are proteins key components of? | Membranes, enzymes, haemoglobin and collagen. |
| What do we get from proteins that are important for us to function? | We get 20 amino acids, 8 of which are essential because we cannot make them ourselves. |
| What are the typical requirements of protein that are needed for... a) an 18 year old male b) an 18 year old female | a) 55g per day b) 45g per day |
| What percentage of our energy comes from proteins? | 13% |
| What is the typical requirement of water for a person aged 18? Why does this amount differ among people? | 2dm^3 per day. Because it depends upon conditions such as temperature, humidity and the level of exercise in each individual. |
| There is evidence to suggest that dietary fibre... | Prevents bowel cancer and reduces cholesterol. |
| What are the typical requirements of dietary fibre for... a) an 18 year old male b) an 18 year old female | a) 22g per day b) 17g per day |
| What does DRV stand for? | Dietary Reference Values. |
| What is EAR? | The DRV for energy. |
| What does EAR depend upon? | Age, gender, physical activity level and the environment. |
| What does malnutrition mean? What are the two types of malnutrition? | It simply means bad nutrition. There is under-nutrition (commonly associated with famine) and over-nutrition (obesity). |
| What commonly causes famine? | Drought, overpopulation and war. |
| What commonly causes obesity? | Convenience foods, processed foods with a lot of fat, salt and sugar. |
| What type of malnutrition was commonly found in the UK in the 19th and early 20th century? What did this lead to? | Under-nutrition caused by poverty. Deficiency diseases and contributed to early deaths. |
| What type of malnutrition was most commonly found in the late 20th century? What did this lead to? | Over-nutrition caused by wealth and lifestyle. Excess energy is stored as fat in the adipose tissues under the skin and around the major organs - this results in obesity and can result in early death. |
| What are the figures that suggest that cases of obesity are on the increase? | 1 in 4 men and 1 in 5 women are obese and the incidence in children is also increasing. |
| What does obesity increase the risk of? | Type two diabetes, CV disease, arthritis, cancer and hypertension. |
| What is type two diabetes? | The body stops producing insulin or the insulin produced becomes less effective (insulin resistance). |
| What are the epidemic dietary causes of obesity? | Fast food that is energy dense (has refined sugar and fat) and food is readily available and cheap. |
| What are the epidemic lifestyle causes of obesity? | Hyperkinetic activity- less exercise/manual work, more sedentary activity, greater car use, couch potatos. And central heating- this means you burn less calories from shivering. |
| Could obesity be caused by genetics? | Maybe, we could be programmed to eat food when food is available. |
| What factors can contribute to CHD (Coronary Heart Disease)? | DIET, obesity, high blood pressure, lack of exercise, smoking, excessive alcohol intake, stress, age, gender and genetics/ hereditary factors. |
| What is coronary heart disease? | A degenerative disease of the blood vessels that supply the heart. |
| How is CHD developed? Step 1 | Deposition of fatty material (cholesterol) in the walls of the coronary arteries. |
| How is CHD developed? Step 2 | The diameter of the of the lumen is reduced/ becomes more narrow. |
| How is CHD developed? Step 3 | The narrowing of the lumen restricts the supply of oxygen to the cardiac muscle. |
| How is CHD developed? Step 4 | The demand for oxygen can't be met which causes damage to the heart tissue and could be fatal. |
| Where has there been an increased incidence of CHD? | In the developed world. |
| Where specifically in the artery wall is cholesterol deposited? | Under the endothelium. |
| What happens to the artery wall as more cholesterol becomes deposited? | 1) It becomes less flexible 2) Pushes into the lumen (makes it narrower and restricts blood flow) 3) Makes the surface rough (slows blood flow and increases tendency for blood to clot) |
| If atheroma continues to get larger what could happen? | Could restrict blood flow or block off artery completely. |
| What are the two ways that an artery can be blocked? | 1) Narrow rough edge causes sticky platelets to clot and block the artery (in situ) 2) An embolus (dislodged clot) gets trapped in the narrow artery |
| What are the three types of CHD? | 1) Angina 2) Myocardial infarction (Heart attack) 3) Heart failure |
| What is angina? | Chest pains when exercising due to oxygen shortage to the heart muscle but the muscle doesn't die. |
| What is myocardial infarction (heart attack)? | Blood clot lodges in a branch off an artery, blocks off a section of the heart and the muscle dies. Could recover or die depending where the clot lodges. |
| What is heart failure? | Blood clot causes accumulative damage to heart muscle and the heart can't pump properly. |
| How does salt affect CHD? | HIGH SALT INTAKE LOWERS WATER POTENTIAL: - more water moves into blood - increases blood volume - increases blood pressure - damages artery lining (phagocytes invade and increases smooth muscle and cholesterol) |
| How does cholesterol affect CHD? | Increase blood cholesterol can increases the amount of cholesterol deposited in the arteries. |
| What type of foods have high cholesterol? | Foods containing a lot of fat such as; -red meat -eggs -dairy |
| How much blood cholesterol should we be aiming for? | < 5 mmol per dm cubed |
| Why should we still keep cholesterol in our diets? | It is important for many functions in our bodies such as; - Bile - Stabilising membranes - Source of steroid hormones - The synthesis of vitamin D in subcutaneous fats |
| Why is blood cholesterol unavoidable? | Our liver makes cholesterol. |
| Our blood cholesterol levels should be... | Self-regulating. |
| Lipids are essential in a diet.. What are the two types of lipids and where do you find them? | Saturated- animal fats Unsaturated - fish/plant oils |
| What type of lipid is beneficial in our diets? | Unsaturated. |
| What type of lipid isn't beneficial in our diet? | Saturated. |
| How does dietary fibre said to reduce the risk of CHD? | There is evidence that some dietary fibre can reduce cholesterol (e.g. oat fibre) |
| Can too much dietary fibre be too bad for us? | Yes, -Rapid transit -Flatulence - Minerals bound to fibre |
| Does alcohol increase the risk of CHD? | Depends on the uptake. |
| How can alcohol decrease the risk of CHD? | Moderate uptake can reduce the risk of CHD as its a relaxant and has antioxidant properties. |
| How can alcohol increase the risk of CHD? | Excessive uptake causes the liver to produce more cholesterol as alcohol gives us energy is shifts the metabolism which causes fat to be produced and the liver converts this fat into cholesterol. |
| What is a lipoprotein? Why do we need them? | It is a lipid coated in a layer of protein Because lipids are insoluble in water but need to be transported in a liquid medium. |
| What are the two types of lipoprotein? | High density lipoprotein (HDL). Low density lipoprotein (LDL). |
| What are HDLs composed of? Good or bad? | Unsaturated fats, cholesterol and high proportions of protein. Good. |
| What are LDLs composed of? Good or bad? | Saturated fat, cholesterol, low proportions of protein. Bad. |
| What are HDLs said to do in relation to CHD? | They reduce blood cholesterol and may even remove cholesterol from artery walls. |
| What do HDLs do? | They bind to receptors in the liver where absorbed by liver cells and broken down to make bile. |
| What do LDLs do? | Transport cholesterol from the liver to the rest of the body cells. |
| Where does all the food we eat come from originally? Why? | Autotrophic plants (self feeders). Because photosynthesis is used to make sugar and starches and nitrates and minerals from the soil is used to make amino acids and other nitrogenous compounds, these are then eaten by herbivores and then carnivores. |
| What does the general diet have more of? | Carbohydrate staples such as; -potato -rice -pasta/other cereal derivatives. -corn |
| What is diet like in developed countries? | More protein and lipids than carbohydrate-rich staples. |
| Why is there more demand for food production? | Increasing population and better living conditions. |
| How could we improve food productions? (4) | 1) Put more land into cultivation. 2) Increase the percentage yield. 3) Increase growth rate. 4) Reduce loss from pests and disease. |
| What was the desirable characteristics of a plant that early farmers chose to breed? (4) | 1) Larger seed. 2) More seed. 3) Seeds/fruits retained before harvest. 4) Good storage properties. |
| What was the desirable characteristics of an animal chosen by early farmers to breed? (4) | 1) Docile. 2) Milk yield. 3) Meat yield. 4) Growth rate. |
| What did the artificial selection of plants/animals by early farmers result in? | A gradual change or evolution of domestic animals and plants. |
| What is selective breeding? | Humans select the individual organisms that are allowed to breed according to the chosen characteristic. |
| Who provides the selection pressure for selective breeding? | Humans. |
| What does the speed of characteristics changing depend on? Which is slower and why? | Whether the characteristic is controlled by a single gene or is polygenic (controlled by many different genes). Polygenic, because each gene only makes a slow contribution to the overall feature. |
| What is increasing due to the demand of increasing food production? (2) | 1) Mechanisation. 2) Use of agrichemicals. |
| What are the concerns of increasing mechanisation and use of agrichemicals? (2) | 1) ENVIRONMENTAL EFFECTS: Eutrophication, limits of fertiliser supply and health concerns. 2) ANIMAL WELFARE: Intensive farming, disease and lack of genetic diversity. |
| What did the concerns of increased mechanisation and use of agrichemicals lead to? (4) | 1) Use of manure/dungs 2) Use of natural pesticides 3) Limited range of chemicals used 4) A return of pre-traditional farming |
| How do we maintain soil fertility and crop production? (2) | 1) Minerals removed by crop must be replaced. 2) any deficiency must be made good. |
| The Irish became dependant on one breed of potato (Lumper) which was high yielding but non-resistant to blight and so when infected the Irish Potato Famine occurred... What did they have to do to resolve this? | They had to breed the Lumper with a wild variety of potato that was resistant to blight to produce a high yielding plant that was resistant to blight. |
| In many cases nitrogen is a limiting factor which doesn't allow and increase of plant production, what can be done to fix this? (3) | Fixed nitrogen can be supplied to the plants by... 1) Decomposition and nitrification 2) Biological nitrogen fixation 3) Chemical nitrogen fixation |
| What are the traditionally organic fertilisers and ploughed in legumes that have been used? (3) | 1) Human/animal dungs 2) Seaweed 3) Rotations that include legume (peas, beans, clover, alfalfa) |
| What is a fertiliser? | Minerals needed for plant growth, which are added to soil to improve its fertility. |
| What is eutrophication? | Leached nitrates cause... 1) Increase algal and aquatic plant growth (greeny ponds) 2) Death of submerged/rooted aquatic plants and algae (lack of sunlight) 3) Increased Biochemical Oxygen Demand (BOD) from decomposition (can result in oxygen depletion) 4) Migration or death of oxygen sensitive animals (salmon, trout, mayfly and caddis fly) |
| What can cause eutrophication? | Excessive use of fertilisers. |
| What else other than eutrophication does overuse of fertilisers cause? How? | Reduction in species diversity in pasture. Grass growth is stimulated more than the growth of any other species and so grass outgrows any other species and uses most of the sunlight and the other species die. |
| What are pesticides? | A chemical that is designed to kill pests. |
| Define a "crop pest"... | An organism that causes harm or disease to the crop. |
| What can pests reduce? (3) | 1) Productivity 2) Yield 3) Marketability |
| What type of organisms are included under "pests"? | 1) Animals (insects, molluscs (slugs and snails), rabbits and rodents) 2) Microbes (fungi,bacteria and virus |
| What does an insect pest do? | Feeds on the plant... -Parts that are harvested (fruits/seeds) -Leaves (decreases productivity) -Roots (decreases water/mineral uptake) ...Which results in a reduced yield. |
| How is a weed a pest? | It competes with the crop... -for light -for water -for minerals ... Which reduces the yield. |
| What are the five different pesticides? | 1) Insecticides (kills insects) 2) Herbicides (kills plants/competing weeds) 3) Molluscicides (kills molluscs) 4) Rodenticides (kills rodents) 5) Fungicides (kills fungi) |
| What are the two types of insecticides? | 1) Organochlorines 2) Organophosphates |
| What are the properties of organochorines? (3) | 1) Synthetic 2) Have DDT in them 3) High persistance |
| What are the properties of organophosphates? (2) | 1) Synthetic 2) Highly toxic (nerve poison) |
| What are the four major issues surrounding pesticides? | 1) Toxicity 2) Persistence 3) Specificity 4) Bioaccumilation |
| Why is toxicity a major issue around pesticides? | Synthetic pesticides are extremely toxic especially organophosphates which were originally designed for chemical warfare as they affect the nervous system. |
| Why is persistence a major issue around pesticides? | Many or non-biodegradable and therefore many stay in the environment especially with the organochlorines which have DDT (softens birds egg shells). |
| Why is specificity a major issue around pesticides? | There is no specificity in pesticides so it affects the target species and the non-target species which means it could be killing off pests that we need such as pollinators and natural control agents (things that prey on pests). |
| Why is bioaccumulation a major issue around pesticides? | Some harmful toxins are non-biodegradable, these toxins once inside an organism cannot be excreted and are stored in the fatty tissues of the organism and so further up the food chain the toxin accumulates and becomes more concentrated in the longer-lived top level carnivores. |
| What could we use instead of pesticides? What is this? | Biological Pest Control. Uses biological agents (predators/competitors) to control pests. |
| The Cane Toad was an example of Biological Pest Control... Why was this unsuccessful? | Scientist introduced the Cane Toads were introduce to Australia because the Cane Beatle was eating all the sugar cane. The Cane Toads didn't eat the Cane Beatles but ate all of the other pond life instead because they hatched quicker. Cane Toads have poisonous glands on their back which killed any animal which ate them and so the Cane Toad became a pest itself. |
| What can we use as a Biological Pest Control? (3) | 1) Insect Parasites 2) Carnivorous Predators 3) Natural Pathogens (bacteria/virus) |
| What are the advantage of using Biological Pest Control? (4) | 1) Ideally specific so only one pest affected 2) Doesn't use chemicals so no bioaccumulation or bio-magnification 3) Control organisms become established no need for reapplication 4) Pest doesn't develop a resistance. |
| What are the disadvantages of using Biological Pest Control? | 1) Slower (they take time to get a big enough population) 2) Pest may not be eradicated 3) Care needed for proper research (time and money) 4) Unpredictable (dealing with living organisms) 5) Control species may become pest itself. |
| What are the two types of herbicides? | 1) Contact 2) Systemic |
| What does a contact herbicide do? | It kills the part of the plant that it comes into contact with, the roots aren't affected so they can regrow and you need to keep reapplying it. |
| What does a systemic herbicide do? | It kills the whole plant including the roots so it can't regrow and there isn't a need to reapply it. |
| What types of animals are reared intensively? | Animals that provide poultry, dairy and beef cattle. |
| What has selective breeding inadvertently caused? | A breed of animal with very similar susceptibilities to disease due to a very small gene pool. |
| What can antibiotics be used for in reference to animals with similar disease susceptibilities? (4) | 1) Treat a disease 2) Used as a prophylactic to prevent disease 3) Lower levels of antibiotics in feed 4) Acts as a growth promoter. |
| What are the concerns around use of antibiotics in animals? (3) | 1) Residues in meat and milk 2) Development of antibiotic resistance 3) Transfer of resistance to human pathogens |
| What do hormones affect in animals? | The growth and development of the animal |
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