Carbohydrates Flashcards
What are carbohydrates?
They contain the elements carbon, hydrogen and oxygen (CH2O). They include sugars, starches and fibres.
Where can we find Carbohydrates?
Found in rice, potatoes, bread, yams, beans, sugar, honey, milk, popcorn, cookies, spaghetti, soft drinks, corn, fruits.
Unhealthy foods
white bread, pastries, sodas, and other higly processed or refined foods.
Healthier foods
Unprocessed or minimally processed whole grains, vegetables, fruits and beans.
Monosaccharides
Carbohydrate made of one unit of sugar. Building blocks (monomers) of all carbohydrates.
Common monosaccharides
Glucose, fructose and galactose
Glucose
Simple sugar
Used in respiration and transported in the blood
Water soluble
Energy source for cells
Fructose
Sugar in fruits and plants
Galactose
Sugar in milk
Disaccharides
Formed when monosaccharides are joined together through dehydration reactions forming glycosidic linkages.
Common disaccharides
Maltose, sucrose and lactose
Maltose
Malt sugar
Made up of two glucose molecules
Sucrose
Table sugar
Made up of glucose and fructose
Lactose
Milk sugar
Made up of glucose and galactose
Polysaccharides
Formed when glucose monomers link together to form long chains. These long chains of glucose units are ideal for storing energy. The chains can be straight or branched.
How plants store energy (starch)
They store energy in the form of amylose (straight chains) or amylopectin (branched chains)
How humans and animals store energy
Animals differ from plants in that they store energy in the form of glycogen, which is a highly branched polysaccharide that can be broken down quickly to supply energy to tissues.
Examples of polysaccharides
Cellulose, chitin and peptidoglycan (serve as structural molecules in organisms)
Cellulose
Found in cell walls of plants
Chitin
Forms exoskeleton of insects and crustaceans
Peptidoglycan
Found in cell walls of bacteria
What do carbohydrates do?
They provide us with with a source of energy that is easily respired. Simple sugars are abrorbed almost immediately by the stomach into the blood to give an immediate source of energy. This energy is released as a result of respiration.
Complex carbohydrate found in plants (polysaccharides)
Starch
Complex carbohydrate found in animals (polysaccharides)
Glycogen (stored in liver and muscles)
Simple sugar (monosaccharides and disaccharides)
Glucose
Starch stores
Energy
