processing nutrition: 1.digestive system: eat food that gets absorbed and transformed into nutrients...
TRANSCRIPT
Processing Nutrition:1. Digestive System: eat food that gets absorbed and
transformed into nutrients for cellular use.2. Respiratory System: require oxygen to use the
nutrients we eat.3. Cardiovascular System: blood circulates nutrients and
oxygen to cells.4. Urinary System: waste is discarded in blood and
filtered out in liquid form.
Ch. 6: Human Organism and the Importance of Nutrition
You Are What You Eat!• Food: substance to be ingested
sustaining life. Supplies body with nutrients.
• Nutrient: substance found in food that is used by the body for various purposes.
– 6 nutrients: • Carbohydrates • Fats/Lipids • Protein• Vitamins• Minerals • Water
• Energy: Is the ability to do work measured in joules (J).
• For food the common unit of measure for energy is dietary calorie.
• Calorie (Cal): 1 Cal is equal to 4000 J or 4 kJ.
*Adolescent girl: 1800 Cal (7200kJ)-2400 Cal (9600kJ)*Adolescent boy: 2200 Cal (8800kJ)-3200 Cal (12
800kJ)
*3 factors to measure calorie output: basal metabolic rate (BMR), physical activity, and the digestion of food.
Measuring Calorie Output:• BMR: is the amount of energy required by
the body to carry on its vital processes while at rest. Ex: respiration, circulation, cellular metabolism and maintaining body temperature.
• Physical activity: the energy required for physical activity is a function of the type of activity, the duration of the activity, and the size of the individual.
• Food digestion: the active process of breaking down, absorption, and assimilation of food.
Calorie Input and Output• Energy balance reflects the
relationship between incoming and outgoing calories.
• Three relationships are possible:– input = output; body weight
maintained– input > output; body weight
increase– input < output; body weight
decrease
– 4 sources of calories: protein, fat, carbohydrates, and alcohol.
– Fibre: is cellulose, comes from cell wall of plants. It can’t be digested by the human body.• It helps prevent constipation, helps to
absorb water, stimulates contraction of the intestine.
– Carbohydrates, fats, and proteins are complex molecules that need to be broken down into smaller molecules.
• Main function: provide energy for cells.• Cellular respiration: Glucose + Oxygen Energy + Carbon dioxide + Water
C6H12O6 + O2 ATP + CO2 + H2O
Carbohydrates
• consist mainly of sugars (polysaccharides, disaccharides or monosaccharides).– Are broken down into glucose.– Found in: fruits, breads, pasta, rice, some vegetables, honey,
juice, candy, grains, flour, legumes and tubers (beets, potatoes, turnips)
– Function: Provides main source of energy– Provides energy: 4 Cal/g (17 kJ/g). – Energy can be used rapidly
Fats/Lipids• Found in: oils from plants and animals Ex:
dairy products, eggs, margarine, nuts, meat, chips, fish
• Fat is broken down into fatty acids and glycerol.
• Function: – Energy usually stored by the body;
available over longer periods of time.– Building blocks of hormones, cell
membrane and protects organs, insulator.
• Source of energy; 9 cal/g (38 kJ/g)• Stored in fat (adipose) cells.
Proteins
• Large molecules consisting of long chains of amino acids.
• Found mainly in meat, poultry, fish, meat substitutes: nuts, legumes, eggs, tofu and milk products.
• Proteins are broken down into amino acids.• Function: Allows the body to build and repair
tissues (bones, muscle and skin)– Body’s last choice for energy.– Are the basic building blocks for cells
• Provides energy: 4 Cal/g (17 kJ/g).
• Vitamins, minerals and water are simple molecules that can be used directly by the cells (Don’t need to be broken down).
Vitamins• vital to all the body’s functions• 13 types including: A, B, C, D, E and K.• Found in:fruits, vegetables (esp. dark green and orange
veggies), eggs, meat substitutes, milk, grains, and nuts• Function: for proper growth and repair, regulation of
metabolism (regulate chemical reactions in the body), helps fight infections by strengthening immune system.
• Fat Soluble Vitamins: are absorbed through the intestinal tract with the help of lipids (fats). They are more likely to accumulate in the body. (A, D, E and K)
• Water Soluble Vitamins: dissolve easily in water, and in general, are readily excreted from the body. Consistent daily intake is important. Many types of water-soluble vitamins are synthesized by bacteria. (8 B vitamins and vitamin C).
Minerals• Are simple chemical elements• Include: calcium (Ca), potassium (K), sodium (Na),
phosphorus (P) and iron (Fe).• Found in: fruits, vegetables, legumes, meat, milk and
fish.• Only need a small amount of minerals.• Function: play a role in the makeup of various tissues
(cartilage, teeth, bones and nerves), regulation of metabolism and are essential to nervous system and muscle contractions, transport oxygen.
Water
• A pure substance that makes up about 70% of the human body.
• Found in most food; mostly in beverages, fruits and vegetables.
• Body needs ~2-3 L per day.• Function: Important in chemical reactions,
regulate body temperature, transports nutrients and waste products.