Carbohydrates | DAT
Carbohydrates
• Have the formula CnH2nOn,
where n is a number
• Common carbohydrates are
pentoses (n=5) & hexoses (n=6)
• The most common carbohydrate
we will encounter is glucose
o It is a hexose and it can
appear as a chain or a ring
•
Glycogen is a polymer of glucose
o It is found is all bodily
cells, but especially in
muscle and liver cells
Glycogen
Glycogen is a polymer of glucose, and it is used
for energy storage.
•
Glucose
Glucose, a hexose, can appear as a straight chain
or in its preferred form- a ring.
•
For a more in-depth review of
carbohydrates’ properties, see the
organic chemistry lecture on
carbohydrates
The liver monitors the supply of
glucose in the bloodstream
o When glucose levels are
low, glycogen is broken
into glucose, which is
released into the blood
Carbohydrates in the Body
• Most carbohydrates are
converted to glucose before our
bodies process them
The Liver Regulates Glucose Levels
When blood glucose levels are low, the liver
breaks glycogen into glucose molecules, which
can then be released into the blood stream.
•
Most Carbohydrates are Converted to
Glucose in Our Bodies
•
Glucose is oxidized to harness its
energy
o That energy can be:
Converted to ATP
if needed
Stored in the form
of glycogen if
ATP isn’t needed
Once in the blood stream, insulin
helps bring the glucose into cells
o More on this later
Carbohydrates in Plants
• We’ve seen that animals store
glucose in the form of glycogen
• Plants store glucose as:
o Starches:
• Amylose
• Amylopectin
o Cellulose
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© 2017 J Co Review, Inc., Accessed by Guest on 06-18-2017
Carbohydrates | DAT
Glucose Storage
Animals store glucose in the form of glycogen,
while plants utilize amylose, amylopectin (not
shown), and cellulose. Don’t worry about
knowing structures for any of these molecules.
•
•
•
•
The starches (amylose and
amylopectin) have α 1-4 linkages
Cellulose has β 1-4 linkages
Animals can digest the α linkages
of starches, but not the β linkages
of cellulose
For a chemical explanation of
these different types of linkages,
see the Organic Chemistry
lecture on carbohydrates (ch. 6)
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© 2017 J Co Review, Inc., Accessed by Guest on 06-18-2017