Leaving Cert Home Economics 2013

Complete the table below in relation to the biological functions of protein. Type                                                                           FunctionStructural Proteins                        Growth & repair of body cells, muscles and skin; Physiologically active Proteins     Production of hormones, enzymes, antibodies,                                                             blood proteins, nucleoproteins;  Nutrient Proteins                           Production of hormones, enzymes, antibodies,                                                             blood proteins, nucleoproteins; 

In relation to lipids, explain each of the following terms:  (i) Oxidative rancidity  This occurs as a result of a reaction which takes place between unsaturated fatty acids and oxygen in the air; oxygen combines with the carbon atoms at the double bond; causes unpleasant rancid smell due to the production of compounds i.e. aldehydes and ketones, etc. (ii) Hydrolytic rancidity  This occurs when enzymes (lipases) hydrolyse fats, breaking them down into fatty acids and glycerol; micro-organisms present in fat foods may also produce enzymes which can give fats an unpleasant taste and smell; occurs in freezers when enzymes are not destroyed, etc. 

The conditions listed below are caused by a deficiency in the diet of specific vitamins.  Identify the vitamin in each case. Conditions                                              VitaminNightblindness                                  ARickets                                              DPoor Blood Clotting                          KAnaemia                                           C; B12; Folic Acid/Folate Beri-beri                                           B1/ThiamineNeural tube Defects                          Folic Acid/Folate

Name three types of flour and suggest a different culinary use for each. Wholemeal Flour - Breads, Pizza bases, etc.Gluten Free Flour - Coeliac products, etc.High Ratio Flour - Confectionary, etc.

Differentiate between the following dairy spreads and give one example of each.   Low-fat spreadsThese spreads contain approx. half the fat of butter (38-40%); suitable for those on a low calorie controlled diet – they contain 95kcal per 25g versus 185kcal for margarine or butter; ingredients include water, vegetable oil and milk proteins; they are low in saturates and high in mono-unsaturated fatty acids; can be used as a spread but not suitable for baking or frying due to high water content, etc.Example - Dairygold Light; Avonmore Extra LightFunctional dairy spreads  Proven to reduce cholesterol; made from sunflower oil, vegetable oil, buttermilk, plant stanol, water and salt; the plant sterols (stanol ester) prevents the absorption of cholesterol in the small intestine so that it is excreted from the body; there are no hydrogenated fatty acids and virtually no trans-fatty acids in these spreads, etc.  Example - Benecol, Flora Pro-Active

In relation to freezing explain each of the following:  Quick freezing  Food is frozen quickly at -25ºC to -40ºC in the fast freeze section of a freezer; small ice crystals form  within the food, causing less damage to the cell walls of the food; nutritive value, texture, colour and  flavour are better retained than with slow freezing, etc. Slow freezing Slow freezing occurs at 0ºC to-24 ºC or above; ice crystals are big and damage the food cells; causing loss of texture, nutrients, colour & flavour on thawing, etc. 

Differentiate between each of the following micro-organisms:   Aerobic micro-organisms: require oxygen to survive, etc.    Anaerobic micro-organisms: can thrive without oxygen, etc.   Facultative micro-organisms: adapt to aerobic/anaerobic conditions, etc. 

State the function of each of the following refrigerator parts:   Compressor: Contains the gaseous refrigerant, etc.    Condenser: Cools the gaseous refrigerant, changing it to a liquid, etc.    Evaporator: Converts refrigerant back into a gas, drawing heat from inside the fridge and keeping food cold, etc 

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