Transcript ORGANIC MOLECULES OF THE CELL

Concept 5.2: Carbohydrates provide
fuel and building material
Counting “Carbs” (aka Sugars)
• Carbohydrates contain carbon, hydrogen,
and oxygen in the ratio: 1C : 2H : 1O
• Basic molecular formula: CH2O.
• Usually found as carbon skeletons that
have a ring shape.
Which of the following is NOT a
valid formula for a carbohydrate?
A.
B.
C.
D.
C4H10O4
C5H10O5
C6H12O6
C7H14O7
Basic molecular formula:
CH2O
“carbo”
(carbon)
“hydrate”
(water)
Carbohydrates Come in Many Forms
• Monomer = Monosaccharides
Example: Glucose (C6H12O6)
• Dimer = Disaccharides
Example: Sucrose (C12H22O11)
• Polymer = Polysaccharides
Example: Starch
What is the name of this
carbohydrate?
A.
B.
C.
D.
starch
glucose
sucrose
fructose
Note the six carbon atoms in
a ring-shaped arrangement.
Glucose:
C6H12O6
Lactose is a monosaccharide.
A. True
B. False
Lactose
People who are
“lactose intolerant”
are unable to
metabolize lactose.
MILK
Lactose is a disaccharide
composed of two
monosaccharides: glucose &
galactose.
Glucose is hydrophilic.
A. True
B. False
This is due to its many hydroxyl groups. Recall that the
hydroxyl functional group attracts water. Therefore,
monosaccharides and disaccharides dissolve readily in
water, forming sugary solutions. Starch and cellulose do
not dissolve readily, but they do attract water.
Functions of Carbohydrates
1) Short Term Energy
– Monosaccharides (plants & animals)
• Example: fructose
2) Long Term Energy
– Polysaccharides
• Starch (plants)
• Glycogen (animals)
potatoes
turkey
3) Structure
– Polysaccharides
• Cellulose (plant cell walls)
• Chitin (animal exoskeletons)
cellulose
chitin
Examples of
Polysaccharides
Which of the following carbohydrates
would you NOT expect to find in a plant?
A.
B.
C.
D.
chitin
starch
glucose
cellulose
Chitin is found in the exoskeletons
of arthropods like this spider, not in plants.