NUTRIENTS
Nutrients
Nutrients - Substance found in food that keeps your body functioning.
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Function of Nutrients:
- Fuel your body
- Repair
- Growth
- Maintain body
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Balanced Diet
- Balance (eat everything)
- Variety (Eat different things)
- Moderation (Eat more from macro, less from micro)
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Water (50 - 75% of our body)
- Carries nutrients and waste to and from cells
- Regulates body temperature
- Dissolves vitamins, minerals, amino acids etc. (mode of transport inside body)
- Lubricates joints
- Key component of tissue
- Medium for all chemical reaction (cytoplasm consists of water)
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Amount of water required by a person varies according to:
- How active a person is
- How healthy a person is
- The environmental conditions (adaptability)
Protein
Macro
Fats
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Nutrients
Micro
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Carbohydrates
Vitamins
Minerals
Carbohydrates
- Organic molecules made up of the elements carbon, hydrogen, and oxygen
- Starch and sugars
- Forms supporting structures
- Required for the formation of nucleic acid, e.g. DNA
- To be converted into other organic compounds (E.g. amino acids/fats)
- Synthesizes nectar in some plants
- Main source of energy
- Sweet in nature
-Source: Pasta, bread, cereal, fruits, milk
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Carbohydrates may be classified as single sugars, double sugars, or complex carbohydrates
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Monosaccharides (single sugars)
- Glucose
- Fructose
- Galactose
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Disaccharides (double sugars)
- Maltose (Glucose + Glucose)
- Sucrose (Glucose + Fructose)
- Lactose (Glucose + Galactose)
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Polysaccharides (complex carbs)
- Starch (storage form of sugars in plants)
- Cellulose
- Glycogen (storage form of sugars in animals)
Glycogen and starch are suitable storage materials in cells because they are:
- Insoluble in water (don't change when water potential in cell changes)
- Large molecules (cannot diffuse through cell membrane)
- Can easily be hydrolysed to glucose when needed
- Have compact shapes (occupy less space)
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Disaccharides are made when two monosaccharides go through a condensation reaction.
Condensation Reaction - A chemical reaction in which two simple molecules are joined together to form a larger molecule with the removal of one molecule of water.
Similarly a disaccharide can be broken down into two monosaccharides using a hydrolytic reaction or hydrolysis:
Hydrolytic Reaction - A reaction in which a water molecule is needed to break up a complex molecule into simpler molecules.
Fibre
- Plant material that does not break down during digestion
- Aids in digestion
- Reduces risk of developing heart disease, diabetes, obesity, and some cancers
- Promotes regular bowel movements
- Source: Wherever carbohydrates are in abundance
Polypeptides + amino acids (building blocks of protein)
There are 20 types of amino acids, of which 9 are not present in the body and must be taken from other sources of meat (vegetarians may have disease due to lack of meat and essential 9 amino acids)
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- Provides energy
- Helps build, maintain, repair body tissues
- Synthesis of enzymes and some hormones
- Formation of antibodies to combat diseases
- Source: Meat, egg, dairy
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Lack of protein can cause kwashiorkor in children. Symptoms of the disease include a swollen stomach, and cracked and scaly skin.
Proteins
Fats
- Concentrated form of energy (calories)
- An insulating material that prevents excessive heat loss
- Reduces water loss from skin
- Provides substance for growth and healthy skin
- Enhances taste and texture of food
- Required to carry fat soluble substances in lacteal
- Fat is made of glycerol and fatty acids, and can be broken down into its components using hydrolysis
- Source: Butter, oil, dairy, meat, etc.
Saturated
- Solid at room temperature
- Animal food and tropical oil
- High cholestrol, risk of heart disease increases
Unsaturated (Liquid at room temperature)
Monounsaturated
- Reduces risk of heart disease
- Olive oil, canola oil, nuts, seeds
Polyunsaturated
- Good for you!
- Essential fatty acids
- Fish, oil, vegetables
Cholestrol - Fat like substance which is part of every cell in the body.
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Vitamins
Minerals
ENERGY!
- Potassium
- Sodium
- Calcium