SMHM 4 - CARBOHYDRATE Introduction

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
CARBOHYDRATE Introduction Carbohydrates are an important source of fuel for body cells. Carbohydrates are organized in molecules that are in single (monosaccharide), double (disaccharide), or multiple (polysaccharide) units. Glucose, fructose, and galactose are examples of monosaccharides; sucrose, lactose, and maltose of disaccharides; and starch and fiber of polysaccharides. There are three primary carbohydrate groups: sugars, oligosaccharides, and polysaccharides. Examples of sugars include the monosaccharides glucose and fructose; the disaccharides sucrose and lactose; and the polyols sorbitol and mannitol. Examples of oligosaccharides include maltodextrin and raffinose. Examples of polysaccharides include starch and fiber. Digestion of carbohydrate begins in the mouth with salivary amylase, and continues in the small intestine with pancreatic amylase. For absorption to take place in the intestine, disaccharides and polysaccharides must be further reduced. This is accomplished by enzymes called disaccharidases. Sometimes, necessary enzymes are missing and an intolerance results. Lactose intolerance is caused by an inability to produce lactase, an enzyme which is necessary for digestion of milk sugar. When body supplies of glucose, a carbohydrate, are adequate, ingested protein is used for body maintenance, repair, and growth. When it is not, protein is used for fuel. Recommendations for daily carbohydrate intake are based on the minimal amount needed to prevent ketosis a condition characterized by incomplete combustion of fats resulting in elevated blood ketone levels. Recommended daily intake of carbohydrate is less than most people eat. First described in the 1970s, the term dietary fiber describes carbohydrate derived from plant cell walls including cellulose, hemicellulose, and non­starch polysaccharides. There is a lack of agreement concerning which types of carbohydrate qualify as dietary fiber. Although widely used, the terms soluble and insoluble are inexact. Fiber has three forms: fermentable, non­fermentable, and viscous.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Each form contributes to health in a different way. One of the most important is to provide bulk that promotes a healthy tone in intestinal muscles. Insulin and glucagon regulate blood glucose levels. Insulin helps cells remove glucose from the bloodstream, thereby reducing levels. Glucagon mediates the release of glucose from body stores, such as glycogen, thereby increasing blood levels. Together these hormones maintain an optimal blood glucose level. When the body is unable to produce insulin or cells resist it, diabetes mellitus type 1 or 2 results. Glycemic Index (GI) describes the blood glucose response to a 50 gram portion of a test food when compared to that of a standard food consumed by the same person. Foods with a high GI are digested and absorbed more quickly than those with a low GI.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

SMHM 4 - CARBOHYDRATE Introduction

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online