Carbs

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MacronutrientCarbohydrateChapter 2
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CARBOHYDRATES

• Monosaccharides-2 to 6 carbons-smallest unit of a
  carbohydrate
• Glucose-chief energy source for the body,
  regulated by the hormones
• Insulin (brings glucose into cell)
• Glucagon (releases glucose when blood sugar is
  low)
• Fructose- sweetest of the sugars found in fruit
  and honey
• Galactose-only found as part of lactose-milk
  sugar, a disaccharide

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• Disaccharides- 2 simple sugars linked
• Most important
• Sucroseglucosefructose (table sugar)
• Maltoseglucoseglucose (found in the breakdown
  of stored energy in plants)
• Lactoseglucosegalactose (milk sugar)

Lactose
Sucrose
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A glucose molecule
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• Polysaccharides
• Starch- long chain saccharides
• Glycogen-stored glucose in muscle and liver
• Glucose polymers-synthetic glucose used in
  feeding formulas
• structural polysaccharides-
• dietary fibers- insoluble fiber
• cellulose-plant cell walls
• hemicelluloses
• lignins
• gums, mucilage, algal polysaccharides and pectin-
  soluble fiber
• Sugar alcohols- (nutritive sweetners) not
  completed absorbed

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PHYSIOLOGICAL ROLES of carbohydrates

• Energy
• Lipogenesis- creation of lipids in the body
• Conversion to other carbohydrates
• Transamination process in the synthesis of
  proteins
• Normal fat metabolism
• Protein sparer- when adequate CHO (carbs) are
  consumed, protein is not broken down for energy
• Intestinal bacteria-normal, healthy bacteria
• Gastrointestinal motility- keeps digestion
  processes going
• Other nutrients- supplies vitamins,
  phytochemicals. Etc.

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DIGESTION AND ABSORPTION

• salivary amylase- enzymes in the mouth
• intestinal enzymes
• pancreatic enzymes
• absorption occurs mainly in the lower duodenum
  and jejunum
• Well talk a lot
• more about this
• later

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Carbohydrate Metabolism

• Gluconeogenesis- chemical process whereby energy
  is created by the breakdown of protein
• Glucogenolysis- chemical process whereby energy
  is created by the breakdown of glycogen

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Disorders of METABOLISMinclude

• Glucosuria- glucose in urine
• Hypoglycemia- low blood sugar
• Hyperglycemia- high blood sugar
• OFTEN FOUND IN DIABETES MELLITIS (disease in
  which there is a complete or partial lack of
  Insulin
• Glycemic index measures the extent to which a
  food raises blood sugar and causes a rise in
  Insulin

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REQUIREMENTS

• A reasonable intake- most Americans consume
  enough carbohydrates, but not enough whole
  grains. Carbohydrates should make up
  approximately 50-60 of calories consumed
• One gram of CHO 4
  calories
• Soooooo 100 grams of carb has 400
  calories

Important
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SOURCES

• American diet is about 45 of the total
  kilocalories
• Sources of carbohydrates include grains, rice,
  vegetables, fruit and milk

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HYPER AND HYPO STATES

• Carbohydrate excess- converted to fat and fatty
  acids
• Fiber deficiency- constipation and may lead to
  a number of intestinal conditions
• Dental caries
• Obesity