320 likes | 551 Views
Chapter 4. The Carbohydrates: Sugars, Starches, and Fibers. Carbohydrates most abundant class of compounds found in nature contain the elements C, H and O term “ CARBOHYDRATES ” came from fact that these compounds could be written as “hydrates of carbon”
E N D
Chapter 4 The Carbohydrates: Sugars, Starches, and Fibers
Carbohydrates • most abundant class of compounds found in nature • contain the elements C, H and O • term “CARBOHYDRATES” came from fact that these compounds could be written as “hydrates of carbon” • e.g. C6H12O6 = C6(H2O)6
Simple Carbohydrates (sugars) Monosaccharides
Simple Carbohydrates (sugars) Monosaccharides
Simple Carbohydrates (sugars) Monosaccharides
Simple Carbohydrates (sugars) Disaccharides
Simple Carbohydrates (sugars) Disaccharides
Simple Carbohydrates (sugars) Disaccharides
Simple Carbohydrates (sugars) Disaccharides
Simple Carbohydrates (sugars) Disaccharides
Complex Carbohydrates Polysaccharides (glycogen, starches & fibres) Glycogen – energy storage in animals Starches – energy storage in plants Fibres – provides structure in plants
Complex Carbohydrates (glycogen versus starches)
Plants Animals Starch (amylopectin) and (amylose) Glycogen
Hydrolysis (breakdown) of Complex Carbohydrates Both glycogen and starches can be broken down by the human digestive system to give || Glucose
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Major sources of starch include grains, legumes, and tubers.
Starch digestion in the GI Tract MOUTH: Starches are hydrolysed to smaller and smaller polysaccharides by enzymes referred to as AMYLASE. STOMACH:AMYLASE is deactivated due to acidic pH. SMALL INTESTINE: Pancreatic AMYLASE break starch polysaccharides down more and DISACCHARIDASES break down disaccharides.
Fiber in the GI Tract MOUTH: Fibers are mechanically ripped apart by teeth and moistened. NO ENZYME BREAKDOWN STOMACH and SMALL INTESTINE: NO ENZYME BREAKDOWN LARGE INTESTINE: Bacterial enzymes can break down small amounts of fiber…. FERMENTATION…. CAUSES GAS
Absorption of Monosaccharides Monosaccharides enter directly into the blood capillaries Converted to GLUCOSE Glucose and Galactose are moved across cell membranes by ACTIVE TRANSPORT Fructose moves across my FACILITATED DIFFUSION
The carbohydrates of grains, vegetables, fruits and legumes supply most of the energy in a healthful diet.
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Maintaining blood glucose homeostasis
Diabetes - related to the function of insulin to regulate glucose levels Type I (juvenile diabetes) Type 2 (adult diabetes)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Foods rich in starch and fiber offer many health benefits.
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Carbohydrates on Food Labels
Structure of Artificial Sweeteners Cyclamate (30 X) Saccharin (450 X) Aspartame (180 X)
Sugar Replacers
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license. Dental Caries (cavities)