Transcript Food and Energy

Section 1 of Ch 3 – Food and
Digestion
Food provides the body with…
 Material for growing and repairing tissue
 Energy
Nutrients are the substances in food that provide
the raw materials and energy the body needs
to carry out all essential processes
Food enables the body to maintain homeostasis
 Composed
of carbon, oxygen and
hydrogen
 Major source of energy
 1 gram = 4 Calories of energy
 50-60% of the Calories in a diet
 Provides raw material to make parts of
cells
 Two groups: simple and complex
Simple:
 Sugars
 Found naturally in fruits, milk, & some
vegetables
 Added to cookies, candy and soft drinks
 The body converts sugars into glucose the form of sugar the body can use
 Many
sugar molecules linked together in
a chain
 The body breaks it down into smaller,
individual sugar molecules
 Starch is found in potatoes, rice, corn,
pasta, cereals and bread
 Fiber is found in fruits, vegetables, nuts
and whole grains but cannot be broken
down by the body
 Composed
of carbon, oxygen and hydrogen
 Contain more than twice as much energy as
carbohydrates
 Form part of the structure of cells
 Fatty tissue protects & supports internal organs
and acts as insulation
 No more than 30% in diet
 Classified based on chemical structure as
Unsaturated and Saturated
 Usually
liquid at room temperature
 Oils such as olive and canola
 Some types of seafood such as salmon
 Usually
solid at room temperature
 Animal products – meat
 Dairy products
 Egg yolks
 Some oils such as palm and coconut
 Animal products contain cholesterol - a
waxy, fatlike substance. This is an
important part of the body’s cells but the
liver makes all the body needs
 Contain
nitrogen, carbon, hydrogen and
oxygen
 Needed for tissue growth and repair
 Play a part of chemical reactions within cells
 Meat, poultry, fish, dairy products, nuts, beans
and lentils
 12% of daily Calorie intake
 Made of amino acids - the body makes about
half & the others, essential amino acids, come
from the food we eat
 Act
as helper molecules in a variety of
chemical reactions within the body
 Needed in small amounts
 The body makes a few but most obtained from
food
 Fat-soluble: dissolve in fat & are stored in fatty
tissues. Vitamins A, D, E, & K
 Water-soluble: dissolve in water & are not
stored in the body. Vitamin B & C, Biotin, Folic
Acid, & Pantothenic Acid
 Needed
in small amounts
 Are not made by living things – present
in soil & absorbed by plants through
roots
 Obtained by eating plants foods or
animals that have eaten plants
 Calcium, chlorine, fluorine, iodine, iron,
magnesium, phosphorous, potassium, &
sodium
Most abundant substance in the body
 65% of average person’s weight
 Can survive for weeks without food but only days
without water
 Most important nutrient because the body’s
vital processes – such as chemical reactions to
breakdown nutrients take place in water
 Makes up most of the body’s fluids including blood
 Needed to produce perspiration
 Need at least 2 liters a day
