Download Cellular Energy

Metabolism:
Cellular
Energy
Mitochondria
and
Chloroplasts
Go to Work
Cellular Energy
• The life processes of all organisms require
energy.
• The potential energy held in the bonds of
food molecules CANNOT be used directly by
the cell.
• Energy from food must be converted to the
ONLY energy source that cells can use: ATP!
ATP – Adenosine Triphosphate
 ATP is the energy
molecule that cells use
 Cellular work such as
metabolism, transport,
and movement is
powered by the
breakdown of ATP.
Photosynthesis
Water + Carbon Dioxide -> Glucose and Oxygen
• Plants make glucose
– Foundation of all ecosystems
• Happens in the chloroplasts
– Pigment chlorophyll captures sun’s energy
• Produces and maintains all of the Earth’s
atmospheric oxygen.
Photosynthesis
• Plants make enough glucose to be used
during the night and on cloudy days when
they don’t get sunlight.
• The extra glucose is stored in the cells of the
plant’s leaves.
• When needed, the glucose travels to the
mitochondria to be used in cellular respiration
for the production of ATP.
Cellular Respiration
 Breakdown glucose
 Energy in the bonds of glucose used to make ATP.
 Respiration occurs continuously in all cells of
all organisms. Why?
 2 Types
 Aerobic – With Oxygen
 Anaerobic – NO Oxygen
 AKA Fermentation
Aerobic Respiration
Glucose + Oxygen -> Water + Carbon Dioxide
• OXYGEN!
• VERY EFFICIENT
• Makes 36 ATP per glucose molecule
• Occurs in the mitochondria
• Most organisms on earth are aerobic
• 1 glucose completely broken down to carbon
dioxide and water.
Anaerobic Respiration
• Also called fermentation
• No oxygen is present
• 1 Glucose only partially broken down to form
waste products and 2 ATP
• 2 types
– Lactic Acid Fermentation
– Ethyl Alcohol (Ethanol) Fermentation
Lactic Acid Fermentation
happens in muscle cells when they run
out of oxygen (feel the burn!)
Ethyl Alcohol Fermentation
(ethanol and carbon dioxide produced)
Occurs in bacteria
 used to make
yogurt, cheese, dill
pickles
Occurs in yeast
 used to make
alcohol and bread
Aerobic vs. Anaerobic Respiration
Aerobic
(needs oxygen)
Anaerobic
(no oxygen)
Occurs in:
Most organisms
Mostly yeast
and bacteria
1 glucose
makes:
6 CO2 + 6 H2O
Ethanol + CO2
or lactic acid
Net ATP
production:
36
2
• Why can’t bacteria undergo aerobic
respiration?
• Why couldn’t multicellular
organisms, like humans, exist using
anaerobic respiration?
• Where does the glucose used in
respiration come from?
• Why can plants
perform BOTH
cellular respiration
and photosynthesis?