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Nutrition and Digestion
Biology 20 Unit 1
Key Questions
o How does a single cell like a
fertilized egg grow into an adult
human being?
o What is needed for this growth to
occur?
o How do we obtain or produce these
things?
Vertebrate Nutrition (Directions Ch. 9)
o “...every living organism requires a
constant supply of energy and
molecules to build and repair itself
and to maintain its life activities”
o Nutrients: any substance that is
taken into the body’s cells to fulfill a
vital function.
Nutrients
1. Macronutrients: nutrients that are
required in large amounts (g/kg/day)
a)
b)
c)
d)
Carbohydrates
Proteins
Fats and other Lipids
Nucleic Acids
2. Micronutrients: required in small
amounts (mg or g/kg/day)
a) Vitamins
b) Minerals
3. Special Nutrient
a) Water
Nutrients
o Necessary vs. Essential Nutrients
o Necessary Nutrients: nutrients that
can be made by the body if they
are lacking in the diet
o Essential Nutrients: cannot be
produced by the body, must be
supplied from an external source
1. Macronutrients:
a) Carbohydrates
o Major source of energy for all of
the bodies activities
o CnH2nOn ratio of one carbon
atom to one water molecule
o 3 Major types of carbohydrates
o Monosaccharides
o Disaccharides
o Polysaccharides
a) Carbohydrates
o Monosaccharides :
o simple sugars C6H12O6 (***table 9.2***)
Glucose
Fructose
Galactose
a) Carbohydrates
o Disaccharides
o double sugars (***table 9.2***)
o Maltose (glu & glu)
o sucrose (glu & fru)
o lactose (glu & gal)
a) Carbohydrates
o Polysaccharides: complex sugars
o long chains of mono and
disaccharides
b) Proteins
o Proteins perform a variety of
important functions in the body.
o They are made up of long chains of
amino acids
o the configuration of these amino acids
is very important in determining the
function that a protein performs
b) Proteins
o Amino acids are small molecules
that are the building blocks of all
proteins
o composed of N, C, H, & O
o Have an amino group and an acid
group
b) Proteins
o There are 20 different amino acids
that combine in different ways to
produce a wide variety of proteins
needed by the body
o Necessary amino acids:
o 11 of the amino acids are able to be
produced in the body if required
o Essential amino acids
o The other 9 must be absorbed through
digestion from the foods that we eat, these
amino acids are called
b) Proteins
o Some proteins act as enzymes,
structures that speed up the rate of
a reaction (catalysts), playing major
roles in digestion
o Proteins are also important
structural components of muscle,
tendons, ligaments, bones and teeth
b) Proteins
o Enzymes
b) Proteins
o Proteins found in the food that
we eat are known as either
complete or incomplete
o Complete proteins: Contain all nine
of the essential amino acids (a.a.)
oExamples are meat fish, eggs, and
dairy products
o Incomplete proteins: lack one or
more of the essential a.a.
oExamples come from foods produced
by plants
c) Fats and other Lipids
o More properly called triglycerides,
fats and lipids provide important
functions in the body
o Energy storage/reservoir
o Cushioning of vital organs
o Insulation
o Steroids
o Phospholipids
c) Fats and other Lipids
o Triglyceride is a 3 Carbon chain
glycerol molecule with 3 fatty
acids joined to it.
c) Fats and other Lipids
o Fatty acids are long chains of
molecules that are joined together.
(fig. 9.6 p.213)
o Saturated: Every available bond on
the Carbon atoms contain hydrogen
atoms (Fig. 9.6)
o Unsaturated: Places where hydrogen
is missing
c) Fats and other Lipids
D) Nucleic Acids
o Building Blocks of DNA
o Specific order of bases codes for
building everything that the
cells/body needs
oA
oG
oC
oT
oU
Adenine
Guanine
Cytosine
Thymine
Uracil
a) Dehydration Synthesis
o The formation of long chains of
carbohydrates or proteins or fats
uses a process called
Dehydration synthesis
QuickTime™ and a
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are needed to see this picture.
Dehydration Synthesis
Dehydration Synthesis
Hydrolysis
o Splitting apart the subunits with
water.
o Carbohydrates
o Proteins
o Fats