Autotrophs vs. Heterotrophs
 What
is the purpose of nutrition?
 Nutrition
provides ENERGY for life activities
for ALL living things.
 Autotroph
– organisms that make their own
food
 Examples: multicellular plants and
unicellular algae.
 Heterotroph:
organism that needs to take in
its food from the environment.
 Example: Humans, all animals, fungi, etc.
 How
does nutrition vary among heterotrophs?
 Herbivore
– eats only plants
 Carnivore – eats only meat
 Omnivore – eats both meat and plants
 Humans
are complex organisms. There are 6
essential nutrients needed for the human
body to function properly.
6 Essential Nutrients
 Main
source of energy
 Ex: Bread, pasta, rice, vegetables, fruits
What does the body do with excess
carbohydrates?
- Turns into fat or stored energy
 Why
are fats essential in a diet?
 Stored
energy
 Structure of the cell membrane
 Protects organs
 Insulation from the cold
 Synthesize hormones
 Ex:
Nuts, meat, dairy products, oils.
Saturated vs Unsaturated



Saturated fats are solids
at room temperature
(ie: butter, fat found
on/in meat)
Mostly from animals
Increases bad
cholesterol



Unsaturated fats are
liquids at room
temperature. (ie:
different types of oils)
Mostly from plants
Increases good
cholesterol
 Build
muscle and tissue
 Structure of the cell membrane
 Enzymes, hormones, antibodies
 Last source of energy
 Amino
acids are the building blocks of
proteins
 Human body needs 20 different amino acids


12 can be made by the body
8 are essential – must be taken in through diet
 Meat,
beans, whole grains, eggs, soy, nuts
 Up
to 75% of your total body mass is water
 Water is necessary for



Chemical reactions
Movement of materials into and out of cells
Breakdown of foods during digestion
 Why
do we need to take in water every day?
 We
lose 2.5L of water a day through exhalation,
sweat and urination
Used for building body parts
 Involved in many body functions such as
nerve and muscle action
 Examples:


Calcium, phosphorus, zinc, sodium, iodine, iron,
potassium
 Vitamins
are coenzymes (help enzymes to
function) that are found in food
 Cellulose
– indigestible part of the cell wall
of a plant (fiber)
 Helps to push food through the digestive
tract
 Examples – fruits, vegetables, bran cereals,
nuts