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Note Tour of Atlantic Superstore in Sydney River- during the last 3 weeks of March. Please click on the link below and note that there are72 options. Please fill in as many of those options as possible so as to maximise the opportunity for as many students as possible to attend.
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Note Tour of Atlantic Superstore in Sydney River- during the last 3 weeks of March. Please click on the link below and note that there are72 options. Please fill in as many of those options as possible so as to maximise the opportunity for as many students as possible to attend. http://doodle.com/736ebnu28hc6kzq6
Lecture 21- 28 February 2014 Carbohydrates
Carbohydrates Definition -hydrate of carbon -hydrate means water -carbon is an element
Carbohydrates Definition -literally a carbohydrate then is a hydrate of carbon -remember water is H2O -thus they contain carbon, hydrogen and oxygen -contain 1 oxygen atom and one carbon atom for every two hydrogens -thus overall formula is CH2O
Source -plants take carbon dioxide from air, water from the soil and energy from the sun to make carbohydrates
Types -simple, complex
Types of Carbohydrate • Simple -defined by the way sugar units are linked together -sugar units are called saccharides -a sugar unit is 6 carbons (frequently)
Types of Carbohydrate • Simple -simple includes monosaccharides and disaccharides -monosaccharides are one sugar unit -eg glucose (blood sugar) and fructose (fruits and vegetables) -disaccharides are two sugar units -eg sucrose (table sugar) and lactose (milk sugar) and maltose ( occurs when the body digests starch)
mono- and disaccharides give varying degree of sweetness to foods
Complex -Oligosaccharides -3-10 sugar units linked together -dried beans, peas contain the 2 most common oligosaccharides
Complex -Oligosaccharides -body cannot not break down these two most common oligosaccharides on its own so it requires bacterial enzymes that make these 2 oligosaccharides into gas -this explains why one gets gas after eating beans and peas
Complex Polysaccharides -more than 10 sugar units linked together -some are straight chains -other are branched chains
Polysaccharides -the way that the sugars units are linked to one another dictates whether the body can digest polysaccharides -we can digest starch but not dietary fibre - some dietary fibre can be digested by some bacteria in the large intestine -in the process of such bacterial digestion gas is made
Polysaccharides -plants store sugars as starch -starch comes in two forms -amylose and amylopectin
Polysaccharides -when we eat plants we eat starch (eg bread or potatoes) -animals store sugars as glycogen -when an animal is slaughtered glycogen is broken down as part of the death process down so we eat only trivial amounts of glycogen or no glycogen at all
Polysaccharides -dietary fibre provides structure to plant cell walls -all types of plants have dietary fibre including fruits, vegetables, legumes and whole grains
Polysaccharides -fibres include -cellulose (long straight chains) -pectins (found especially in fruits) -pectins mixed with acid give firmness to jellies and jams -gums- used in ice cream to thicken it
Polysaccharides -fibres are classified as water soluble and water insoluble -this means that they dissolve in water (water soluble) or that they do not dissolve in water (water insoluble) -pectins and gums dissolve in water (water soluble) -cellulose does not dissolve in water (water insoluble)
Polysaccharides -foods rich in soluble fibre fruits- apples, oranges, cranberries vegetables-asparagus, broccoli,carrots nuts and seeds-pecans, peanuts, walnuts legumes-most legumes grains-oat bran, oatmeal
Polysaccharides -foods rich in insoluble fibre fruits- apples, bananas, cherries vegetables-sprouts, broccoli, red cabbage nuts and seeds-almonds, sesame seeds, walnuts legumes-most legumes grains-brown rice, whole wheat breads
Digestion- breaking down foods and their nutrients in digestive tract -eg carbohydrates Absorption- moving nutrients across intestinal wall -eg carbohydrates Transport-moving nutrients around in body -eg carbohydrates