Unit 2: Biochemistry
Honors Biology
Monkemeier
Composed of CxH2xOx
 A simple carbohydrate,
monosaccharide is composed of 3-7
carbons with hydrogen and oxygen.
 There are 200 monosaccharides in
nature
 Glucose is the most prevalent (aka
dextrose or blood sugar)
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Fructose (found in fruits and honey) is the
sweetest of all monosacchrides
Fructose is converted to glucose in the liver.
Galactose is created in mammary glands of
lactating animals and is converted to glucose
for energy metabolism.
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Sucrose is most common dietary disaccharide
and occurs in beet and cane sugar, brown
sugar, sorghum, maple syrup and honey.
Lactose is only found in milk and is often
called milk sugar
Maltose occurs in malt products and in
germinating cereal
 Starch
– plants store glucose in
this form
 Glycogen – animals and fungi
store glucose in this form
 Cellulose – found in cell walls of
plants
 Chitin – exoskeletons in
arthropods
Energy
Source
Structure
◦cellulose
◦chitin
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Indicators change color in the presence of a
specific target.
Benedict’s Solution: detects glucose
Iodine – Potassium – Iodide (I-KI): detects
starch
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Is light blue and detects the aldehyde group
on the glucose molecule.
After heating the solution, if glucose is
present, the Benedict’s solution will turn one
of the following colors: light green, yellow,
orange, red.
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I-KI detects starch.
Normally yellow
I-KI changes to purple in presence of starch