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Published bySamantha Summers Modified over 9 years ago
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Chemical Compounds in Cells and in Our Food pp 52-55 & pp 505-517
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Review of basic chemistry
Element – any substance that cannot be broken down into a simpler substance Ex – carbon, nitrogen, oxygen, hydrogen Atom – smallest unit of an element Compound – two or more elements chemically combined Ex – water, sugar, starch Molecule – smallest unit of most compounds Ex – H2O, C6H12O6, O2, CO2
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Inorganic Compounds Don’t contain Carbon, Hydrogen, and Oxygen
Ex – water (H2O), salt (Sodium chloride), CO2
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Organic Compounds Contain Carbon, Hydrogen and Oxygen
Includes: Carbohydrates Proteins Lipids Nucleic Acids
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Proteins Contain C, H, O, N and sometimes Sulfur Found in many foods
In the cell, used as: part of cell membranes structures of organelles muscles in the body
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Structure of Proteins Made of amino acids
There are 20 different amino acids in living things These aa’s link together to form a large molecule of aa’s in one protein. Change one aa, changes whole protein
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Protein
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Enzymes Special kinds of proteins
Chemicals that speed up chemical reactions in the body without being used up themselves. Here the enzyme helps break a large molecule into 2 smaller ones. Some enzymes join two small molecules to make one larger one.
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Carbohydrates Energy rich C, H, and O Simple sugars - glucose
Complex carbohydrates – made up of many simple sugars attached to each other Starch Cellulose – make up plant cell walls Found in cell membranes, other cell parts, and store energy
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Lipids Fats, oils, waxes Store energy Made of C, H, and O
Contain more energy than carbs
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Nucleic Acids DNA = deoxyribonucleic acid RNA – ribonucleic acid
Made of C, H, O, N, and Phosphorus Contain instructions for cells to carry out all their functions.
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Water Makes up about two thirds of your body.
Most chemical reactions occur in water. Essential for all life.
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Food and Digestion- pp 504-530
Why do we need food? Material for growth, repair Energy Allows body to maintain homeostasis
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Nutrients – substances in food that provides body with raw materials and energy to carry out essential processes Carbohydrates Fats Proteins Vitamins Minerals Water
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Energy Carbs, fats and proteins provide body with energy
Amount of energy in food measured in calories One calorie is the amount of energy to raise the temperature of 1 gram of water 1 degree Celsius
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Calorie or calorie? Calorie – used to measure energy in foods.
1 Calorie = 1000 calories Ex – 1 apple contains 50 Calories or 50,000 calories. The more calories a food has, the more energy it contains.
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Amount of Calories needed?
Depends on physical needs and age of the person Very active people need more Infants and small children need more Older people need fewer
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Carbohydrates 1 gram carbohydrates provides 4 Calories of energy
Provide raw materials to make cell parts Two groups: Simple carbohydrates Complex carbohydrates
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Simple Carbohydrates = Sugars
Found in fruits, vegetables, milk Glucose (C6H12O6) – major source of energy for your cells. Another simple sugar = fructose in fruits
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Complex Carbohydrates
Made of many simple sugars connected Starch – found in potatoes, wheat, rice, corn Fiber (Cellulose) – found in plants, but cannot be digested and passes through your digestive system - helps keep things moving along.
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How much carbohydrates do you need?
50-60% of Calories should come from carbs. Complex carbs are better to eat than simple carbs – sugars give a quick burst of energy, but starches are a longer, more even energy source. Foods high in complex carbs usually have other useful nutrients Foods with lots of sugar usually have fewer other useful nutrients
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FATS Contain more than 2x the energy of carbohydrates Store energy
Parts of cells Protect internal organs Insulate the body
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Types of Fats Unsaturated Fats Saturated Fats
Liquid at room temprerature Oils Considered good for you Saturated Fats Solid at room temperature From animals; a few plants – coconut palm Bad for you
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Cholesterol Saturated fat found in meat, eggs, cheese, etc
Necessary for cell membranes in animals Not needed in diet; liver makes all that is needed. Can clog arteries and lead to heart attack
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How much fat do we need? Should have no more than 30% of Calories in diet from fat Should particularly limit intake of saturated fats and cholesterol Read labels – look for palm or coconut oil, hydrogenated or partially hydrogenated oils – these are bad for you and you should avoid them if you can
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Proteins in the diet For tissue growth and repair
Enzymes speed up chemical reactions Can be used for energy, but not usually About 12% of your daily Calorie intake should be protein
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Amino Acids The body makes about half the amino acids it needs
Rest come from food Complete proteins -contain all of the essential amino acids Meat and eggs Incomplete proteins – missing one or more essential amino acid Beans, grains, and nuts
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Vitamins Act as helper molecules for a variety of chemical reactions in the body. The body makes some – K is made by bacteria in intestine The rest come from foods – eating a wide variety of foods provides all the vitamins needed.
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Types of vitamins – chart p 511
Fat soluble vitamins Dissolve in fatty tissue and are stored there. Includes vitamins A, D, E and K Water soluble vitamins Dissolve in water and not stored in body Needed in diet every day. Includes vitamins B and C
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Minerals Nutrients not made by living things
In soil and absorbed by plants Includes calcium and iron See chart - 512
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Water People die within days of not having water
Makes up about 65% of your body weight The body’s most important functions take place in water Makes up most of the body’s fluids Nutrients are dissolved in water in blood and transported around the body Perspiration Need about 2 liter s of water per day Need more if weather is hot or your are exercising
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Food Guide Pyramid Classifies food into 6 groups and indicates
how many servings from each group should be eaten per day
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Food Labels Allow you to evaluate a single food as well as compare the nutritional value of two foods. Tells: Serving size Calories from fat % daily value of one serving ingredients
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THE END
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