Bruce Krause

Nutrition 225

Lecture Notes Outline - Chapter 4:  The Carbohydrates; Sugars, Starches, and Fibers

 

I.  Purposes of this lecture

    A.  To introduce you to basic carbohydrate chemical structure

    B.  To introduce you to the chemistry you will need for this course

    C.  To discuss the types of carbohydrates, how they are digested/absorbed, and their

                functions.

 

II.  What are the two basic types of carbohydrates?

    A. Simple carbohydrates (two basic types)

 

 

 

    B.  Complex carbohydrates (three basic types)

 

 

 

   

III.  Functions and chemistry

    A.  Basic functions of carbos

 

 

 

 

    B.  Chemistry

                1.  Terms

                    a.  Atom

 

                    b.  Element

 

                    c.  Molecule

 

                    d.  Compound

 

 

                2.  Elemental composition of all carbohydrates

 

 

                3.  Composition of an atom; protons neutrons and electrons

 

                4.  Chemical bonds

                    a.  Definition

 

 

                    b.  In nutrition - most common bond type

 

 

                    c.  Bond numbers needed for common the nutritional elements C, O, N, H

 

 

 

IV.  The simple carbohydrates; the sugars

    A.  The monosaccharides (saccharide means________________)

                1.  Definition

 

                2.  the suffix -ose

 

                3.  Most important monosaccharide is ______________.  Why?

                    a.  In body cells

 

                    b.  In central nervous system

 

                    c.  Chemical formula of glucose

 

 

    B.  Diagrams of glucose(p 92).  Generally drawn in two possible manners

                1.  A straight line drawing (called a Fischer projection). Carbons are numbered 1-6

 

 

 

 

 

                2.  As a ring structure (shown on p92).  Carbons are numbered 1-6

 

 

 

 

                3.  We will simplify the diagram normally and leave out everything except the

                basic shape.

 

 

 

 

    C.  Three major monosaccharides you need to know (G,G,F)

 

 

 

    D.  The disaccharide sugars (M, L, S)

                1.  Definition of a disaccharide

 

                2.  How can these molecules be formed? (Condensation (also called dehydration

                synthesis))

 

 

 

 

 

                3.  Glucose + glucose =

                     Glucose + galactose =

                     Glucose + fructose =

 

                4.  Discuss disaccharide breakdown

                    a.  Process called _______________.  Definition =

 

                    b.  Diagram of hydrolysis

 

 

 

 

                    c. Where does this occur?

 

                    d.  What happens to the non-glucose monosaccharides?

 

                5.  Polysaccharides are defined as

 

 

V.  The Complex Carbohydrates:  Starch, fiber, and glycogen

    A.  Starch

                1.  What is it and where is it found?

 

 

                2.  What are the two types of starches? (p 95)

 

 

 

 

    B.  Glycogen

                1.  What is it and where found?

 

                2.  What is its function?

 

 

                3.  What is its structure? ( p95)  WHY?

    C.  Fiber

                1.  What is fiber?

 

                2.  What are some kinds of fiber

 

                3.  Two basic ways to classify fiber

                    a.  Soluble - functions

 

                    b. Insoluble - functions

 

VI.  Dig and Absorption of carbos

    A.  Mouth

 

    B.  Stomach

 

    C.  S.I.

 

    D.  L.I.

 

    E.  Absorption into the blood

 

 

VII.  Blood Glucose and misc information

    A.  Normal blood glucose level = 80-120 mg/deciliter

    B.  Two hormones that control glucose levels - insulin and glucagon

    C.  Insulin

                1.  When and where secreted; and effect

 

                2.  Function of glucose in muscle cells = ___________________ Glucose cannot

                be stored directly in the cells

                3.  Functions of the liver concerning glucose (2 main functions)

 

    D.  Glucagon

                1.  Where secreted?

                2.  Function

 

    E.  Glycemic effect - describes the effect food has on blood glucose levels; different

                foods break down at different rates so release glucose at different speeds

                1.  Problems with this concept -

 

                2.  How to avoid rapid swings of blood glucose

 

                3.  Diabetes - (inability to produce (or cannot use effectively) glucose)

    F.  Health effects of sugars

                1.  about 139 lbs/person/year

                2.  Recommendation for simple sugar is no more than 10% per day ( remember

                that carbohydrates should be 55-60%/day so simple sugars should be no more than

                about 1/6th of total carbohydrates)

 

                3.  Sugars major health effect is tooth decay

                4.  Sugar is not directly the causal factor of

                    a.  Obesity - extra fat consumed and no exercise far more important

                    b.  Heart disease - a problem only at very high blood glucose levels - obesity,

                                smoking, and inactivity far more important

                    c.  Criminal adults and hyperactive kids