Carbohydrates

1
Carbohydrates

• Chapter 4

2
General Information

• Carbohydrates - (CHO) - A compound that breaks
  down into glucose.
• Glucose - Form of sugar that the body uses to
  make energy.
• CHO made up of carbon, hydrogen, oxygen in
  varying structures. They are classified as
  either simple or complex.
• Simple - Monosaccharides and Disaccharides
• Complex - Polysaccharides

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Types of CHO - Monosaccharides

• Monosaccharides - Are knows as simple sugars.
  They have the form C6H12O6. Each has a different
  arrangement of this.
• Glucose - Blood sugar. There is always a glucose
  in a disaccharide. The storage form of glucose
  is glycogen. It fuels most of the bodys cells,
  and is the exclusive energy supply to the brain,
  nervous cells, and developing blood cells.
• Fructose - Occurs naturally in fruit and honey.
  Used commonly as sweeteners.
• Galactose - Found in Milk, usually attached to
  glucose, not free.

4
Types of CHO - Disaccharides

• Disaccharides - Two monosaccharides put together.
  Glucose is always one of the mono.
• Maltose - 2 glucose together. Found in alcohol
  fermentation. Rarely found in food
• Sucrose - Glucose and Fructose - Found in fruits,
  vegetables, and grains (which makes them sweet).
  It is what is refined to make table sugar.
• Lactose - Glucose and Galactose - Found in milk

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Types of CHO - Polysaccharides

• Polysaccharides - Multiple monosaccharides,
  primarily glucose.
• Glycogen - Storage form of glucose found in
  animals
• Starches - Storage form of glucose found in
  plants (wheat, rice, potatoes, peas, beans).
  They are broken down in the stomach.
• Fibers - Structure of plants (not to be confused
  with starch). Cannot be broken down in stomach.

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Chemical Property Classification of Fiber

• Cellulose - Makes plant cell walls - found in
  veggies, fruits, legumes. Glucose molecules in
  chains.
• Hemecellulose - Main ingredient of cereal fibers
• Pectins - Backbone of Carbohydrates in the form
  of chains of monosaccharrides. Found in fruits
  and veggies, used as thickener in jelly, salad
  dressings, etc.

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Chemical Property Classification of Fiber

• Gums and Mucilages - Monosaccharides found as aid
  to plant injury. Used as additives and
  stabilizers.
• Lignin - 3-Dimensional structure. Found in
  seeds, etc. It cant be digested so it is rarely
  seen unnaturally.

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Solubility Classification of Fiber

• Insoluble fiber - Doesnt dissolve in water
• Wheat bran, whole-grain breads, vegetables
• Will accelerate GI transit, increase fecal weight
  
• Soluble fiber - Dissolves in water.
• Fruits, oats, barley, legumes
• Delays GI transit, delays glucose absorption,
  lower blood cholesterol

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CHO Digestion and Absorption

• We eat CHO to get calories from glucose.
• Mouth - Chewing and presence of enzyme Amalyse in
  saliva starts to break down food. Plants
  (starch) breakdown into polysaccharides and
  maltose.Fiber is not broken down.
• Stomach - Acid as well as enzymes continue to
  breakdown starch. Fiber will stay longer in
  stomach, creating full feeling.
• Small Intestines - It is here where
  polysaccharides are broken down. It contains the
  necessary enzymes, resulting in disaccharides and
  glucose chains.

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CHO Digestion and Absorption Cont.

• Outside Intestines - Sucrase, maltase, lactase
  continue to breakdown their sugars.
• glucose moves into blood stream. Fructose and
  Galactose are transported to and then converted
  into glucose in liver.
• IT takes 1-4 hours to digest all starches.
• Large Intestines - Some starches and fiber remain
  and are not broken down. In L.I.,they attract
  water, which softens stool and allows for easy
  passage.
• Fermentation (breakdown without O2) also occurs,
  producing water, gas and fatty acids needed for
  energy.

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CHO Digestion and Absorption Cont.

• Blood -
• Glucose and Galactose move to blood from
  intestine through active transport.
• Fructose - Diffuses through intestine, which is
  slower than active transport.
• Galactose and Fructose are transported to liver,
  blood takes in glucose in from liver.

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Lactose Intolerance

• Lactase is an enzyme that breaks down lactose.
  Lactase activity is high at birth, decreases over
  time. Some people do not have lactase active at
  birth. If lactose isnt broken down, it stays in
  the intestines, attracting water, causing
  bloating, discomfort, and diarrhea.
• Dietary changes can help, altering dairy
  including eating lactose free diary.