Transcript Topic 15 Carbohydrates

Topic 15
Carbohydrates
and
Related Substances
A Balanced Diet
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A balanced diet is the correct mixture and amount
of the five food groups.
They are:
Proteins e.g.Beans, meat & poultry
Fats e.g.Cheese milk & butter
Carbohydrates: Pasta, rice and cakes.
Vitamins:e.g. A,B,B12,C,E&D
Minerals:e.g.Ca,Fe, Zn & I etc.
Carbohydrates
Carbohydrates are made up of three
elements only i.e. Carbon, hydrogen and
oxygen.
 They have a General Formula of(C)x(H2O)y
 Carbohydrates provide our bodies with
energy.
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There are 3 groups of
Carbohydrate
1. Monosaccharides
(the simplest sugars) e.g.
Glucose and Fructose, both
have formula C6H12O6 ie
Isomers
 2.Disaccharides e.g
Sucrose & Maltose(made
from two monosaccharides
joining together)
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3. Polysaccharides ( made up many
monosaccharides joining together)
eg Starch & Cellulose.
Approx 300 glucose units join together to
make Starch. They join together by means
of a CONDENSATION Reaction i.e.the
removal of water molecules between
monosaccharides. The Formula of starch is (C6H10O5)n
Breaking Carbohydrates Up
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Monosaccharides join by
the removal of water
molecules .i.e.
Condensation Reaction.
To break up
Carbohydrates we ADD
water.This is called
Hydrolysis.
Instead of water our
bodies use Hydrochloric
Acid
Starch
Glucose molecules
Digestion of Food
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For us to receive the benefit of food it must be
absorbed into our bloodstream.
Digestion happens in a number of stages:
First broken down in mouth by chewing and use of
Enzymes in saliva.
Passes down gullet into stomach where Hydrolysis
begins (stomach contains Hydrochloric Acid).
Begins long journey through Small Intestine(22-26ft) and
then into large intestine(4-6ft) where it finally absorbed
into the blood.
Digestion (continued)
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The large Intestine or Gut can be regarded a long
tube which contains tiny pores.
For the food to get through to the other side i.e. the
bloodstream the food molecules must be broken up
into small enough units.
For example Starch must be broken into Glucose
molecules.
Alkanols (Alcohols)
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The Alkanols are another Homologous series with General
Formula CnH2n+1OH
Alkanols are generally used as solvents and cleaning agents.
Ethanol is the alkanol that is present in all alcoholic drinks.
It is made by a process called Fermentation in which sugar is
turned into alcohol
C6H12O6
C2H5OH + CO2
yeast
Yeast acts as a Catalyst since it contains Enzymes (a Biological
Catalyst) which will only work at a specific pH and Temperature
The mixture is finally DISTILLED to increase the alkanol
concentration