Chapter 4 carbohydrates

Carbohydrates


Carbohydrates


Carbohydrates
Classification
• Simple
Carbohydrates:
– Sugars
• Monosaccharides
• Disaccharides

• Complex
Carbohydrates:
– Starches
– Glycogen
– Fiber:
– Soluble
– Insoluble


Chemist’s view of CHO

• Carbohydrates are made of carbon,
hydrogen and oxygen atoms.
• These atoms form chemical bonds.


Atoms and Bonds

Monosaccharides
• Simple sugars
– Mono: one
– Saccharide: sugar

• General formula C6 H12 O6


Monosaccharides
• Glucose
• Fructose
• Galactose


Monosaccharides

Glucose

Hexagon


Glucose



Disaccharides
• Pairs of Monosaccharides
• One is always GLUCOSE

Disaccharides
• Maltose

• Sucrose

• Lactose


Simple Carbohydrates


How the Disaccharides are
formed ?


Condensation
• Chemical reaction that links two
monosaccharides:
• Water is released by putting together the
two monosaccharides


Condensation


Hydrolysis
• Chemical reaction to split a
disaccharide into 2

monosaccharides
• Needs water
• Happens during digestion


Hydrolysis


Complex Carbohydrates


Complex Carbohydrates
• Few (oligosaccharides) or many
(polysaccharides) glucose units
bound/linked together in straight or
branched chains.


Complex Carbohydrates
• Starch - amylose & amylopectin
• storage form in plants
• Energy yielding - 4 kcal/g

• Glycogen - storage form in animals
but is not a dietary source of CHO
• Dietary fibers Non-energy yielding


Glycogen and Starch

Starch - Amylopectin


Starch - Amylose


Dietary Fiber
• Structural parts of plants not
subject to digestion by human
digestive enzymes
• Some are digested by GI bacteria