Nutrition and Digestion

1
Nutrition and Digestion

• Biology 20 Unit 1

2
Key Questions

• How does a single cell like a fertilized egg grow
  into an adult human being?
• What is needed for this growth to occur?
• How do we obtain or produce these things?

3
Vertebrate Nutrition (Directions Ch. 9)

• ...every living organism requires a constant
  supply of energy and molecules to build and
  repair itself and to maintain its life
  activities
• Nutrients any substance that is taken into the
  bodys cells to fulfill a vital function.

4
Nutrients

• Macronutrients nutrients that are required in
  large amounts (g/kg/day)
• Carbohydrates
• Proteins
• Fats and other Lipids
• Nucleic Acids
• Micronutrients required in small amounts (mg or
  ?g/kg/day)
• Vitamins
• Minerals
• Special Nutrient
• a) Water

5
Nutrients

• Necessary vs. Essential Nutrients
• Necessary Nutrients nutrients that can be made
  by the body if they are lacking in the diet
• Essential Nutrients cannot be produced by the
  body, must be supplied from an external source

6
Macronutrients

• Carbohydrates
• Major source of energy for all of the bodies
  activities
• CnH2nOn ratio of one carbon atom to one water
  molecule
• 3 Major types of carbohydrates
• Monosaccharides
• Disaccharides
• Polysaccharides

7
Carbohydrates

• Monosaccharides
• simple sugars C6H12O6 (table 9.2)

Fructose
Glucose
Galactose
8
Carbohydrates

• Disaccharides
• double sugars (table 9.2)
• Maltose (glu glu)
• sucrose (glu fru)
• lactose (glu gal)

9
Carbohydrates

• Polysaccharides complex sugars
• long chains of mono and disaccharides

10
b) Proteins

• Proteins perform a variety of important functions
  in the body.
• They are made up of long chains of amino acids
• the configuration of these amino acids is very
  important in determining the function that a
  protein performs

11
b) Proteins

• Amino acids are small molecules that are the
  building blocks of all proteins
• composed of N, C, H, O
• Have an amino group and an acid group 

12
b) Proteins

• There are 20 different amino acids that combine
  in different ways to produce a wide variety of
  proteins needed by the body
• Necessary amino acids
• 11 of the amino acids are able to be produced in
  the body if required
• Essential amino acids
• The other 9 must be absorbed through digestion
  from the foods that we eat, these amino acids are
  called

13
b) Proteins

• Some proteins act as enzymes, structures that
  speed up the rate of a reaction (catalysts),
  playing major roles in digestion
• Proteins are also important structural components
  of muscle, tendons, ligaments, bones and teeth

14
b) Proteins

• Enzymes

15
b) Proteins

• Proteins found in the food that we eat are known
  as either complete or incomplete 
• Complete proteins Contain all nine of the
  essential amino acids (a.a.)
• Examples are meat fish, eggs, and dairy products
• Incomplete proteins lack one or more of the
  essential a.a.
• Examples come from foods produced by plants

16
c) Fats and other Lipids

• More properly called triglycerides, fats and
  lipids provide important functions in the body
• Energy storage/reservoir
• Cushioning of vital organs
• Insulation
• Steroids
• Phospholipids

17
c) Fats and other Lipids

• Triglyceride is a 3 Carbon chain glycerol
  molecule with 3 fatty acids joined to it.

18
c) Fats and other Lipids

• Fatty acids are long chains of molecules that are
  joined together. (fig. 9.6 p.213)
• Saturated Every available bond on the Carbon
  atoms contain hydrogen atoms (Fig. 9.6)
• Unsaturated Places where hydrogen is missing

19
c) Fats and other Lipids
20
D) Nucleic Acids

• Building Blocks of DNA
• Specific order of bases codes for building
  everything that the cells/body needs
• A Adenine
• G Guanine
• C Cytosine
• T Thymine
• U Uracil

21
Dehydration Synthesis

• The formation of long chains of carbohydrates or
  proteins or fats uses a process called
  Dehydration synthesis

22
Dehydration Synthesis
23
Dehydration Synthesis
24
Hydrolysis

• Splitting apart the subunits with water.
• Carbohydrates
• Proteins
• Fats