Title: Carbohydrates
Introduction:
- CHO’s include the small sugar molecules that are dissolved in sports drinks
as well as the long starch molecules found in pasta and potatoes
- CHO’s can be called upon as an energy source shortly after a meal
- CHO’s can be stored for later use
Sugars
-
Monosaccharides
-
Disaccharides
-Polysaccharides
Glycogen
A carbohydrate is an organic compound made up of
sugar molecules.
Sugars contain the elements carbon, hydrogen and
oxygen in a 1:2:1 ratio
Most CHO’s found in nature have a ring structure
Are simple sugars that contain just one sugar unit
Glucose, fructose and galactose are monosaccharides
All sugars end in ose
Sugar (glucose) is the main fuel supply for cellular
work
Glucose not used for work can be stored as larger
carbohydrates and some may be used to make fat
KNOW THE STRUCTURE OF GLUCOSE
-
Are formed via dehydration synthesis from two
monosaccharides
- The most common disaccharide is sucrose made
from fructose and glucose
- Sucrose is the major sugar in plant sap and maple
syrup
- Table sugar is made from sucrose
- KNOW THE STRUCTURE OF SUCROSE
- Polysaccharides are long chain polymers made up
of many monomers
- Starch is a polysaccharide found in plant cells made
up of glucose
- Humans use starch as energy by breaking it down
to simple glucose molecules
-
Animal cells do not contain starch
Animals store excess sugar in the form of glycogen
Glycogen is stored in the liver. When energy is
needed it is broken down to glucose
Cellulose
-
Affinity for Water
-
Cellulose is a polysaccharide found in plant cell walls
that make them stiff and help to prevent them from
falling over
Cellulose is often referred to as fiber and cannot be
digested by people
All carbohydrates are hydrophilic
Mono and disaccharides readily dissolve in water
Polysaccharides such cellulose do not dissolve but
absorb lots of water – think cotton towels and jeans
that absorb a lot of water and take a long time to dry