Download PowerPoint Presentation - Ch. 6 Cellular Respiration

Ch. 6 Cellular Respiration
6.16 – 6.18
Cells use many kinds of organic molecules as fuel for
cellular respiration
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Where do we obtain most of our
calories?
From fats, proteins, sucrose (di) and
starch (poly)
How are three types of food molecules
used in glycolysis?
Enzymes in our digestive tract
hydrolyze starch (polysaccharide) to
glucose, which is then broken down in
glycolysis
Proteins can be used as fuel but first
must be digested to their amino acid
monomers
Fats can be used after the cell
hydrolyzes them to glycerol & fatty
acids.
How are carbohydrates stored?
Stored as a polysaccharide, such as
glycogen, in our liver & muscle cells.
How is glycogen used between meals?
Glycogen is hydrolyzed to glucose to
serve as fuel between meals.
• What does the cell use
amino acids for?
• To make its own
proteins, or convert
excess amino acids to
other organic
compounds such as
pyruvic acid, Acetyl CoA
or as an organic acid in
the Krebs.
• Why do fats make an
excellent source of fuel?
• The many hydrogen
atoms covalently bonded
to carbon, that the cell
can break for energy,
and of course the many
energy rich electrons.
• Can fats be used in
cellular respiration?
• Yes, by being converted
to intermediates.
• What is the advantage for
animals storing energy as
fat?
• Compact storage of fat. 1
gram of fat yields twice as
much ATP as 1 gram of
starch.
• What does this tell us about
the dieters difficulty to burn
fat?
• To get rid of fat, we need to
expend the same large
amount of energy stored in
the fat in the first place.
• Are all food molecules
destined to become
ATP?
• No, the cell needs
food’s raw material to
make molecules for
repair & growth.
(Biosynthesis)
• What two process are
essential for
biosynthesis?
• Metabolism & cellular
respiration
• Where does the fuel
for cellular respiration
ultimately come from?
• Photosynthesis
• What ingredient does
a plant need to make
food by
photosynthesis?
• CO2 & H2O & energy
from the sun!