Ch. 8.1 & 9
ATP, Cellular Respiration and
Photosynthesis
I. Living things need energy…
A. Moving muscles
B. Building essential
molecules
C. Transporting
substances across cell
membranes.
II. Where do we get energy?
A. Food
1. to grow
2. to reproduce.
III. Sources of Energy
A. Autotrophs (plants)
1. can make own food
2. by process of
photosynthesis
3. also called Producers
B. Heterotrophs
1. get food from others
2. called consumers
Plants and animals need each
other to survive.
IV. Chemical Energy
A. Stored in chemical bonds of
compounds.
B. Compounds that store energy:
ATP, NADH and FADH2.
Building Bonds = stores energy
Breaking Bonds = releases energy
So what does ATP stand for?
Many Uses
1. Mechanical functions
of cells
2. Carry out Active
transport
3. Breakdown large
molecules
Adenosine Triphosphate
The Three Components of ATP
Adenine
Go to
Section:
Ribose
3 Phosphate groups
How does ATP store energy?
1. Energy is stored in ATP’s
high-energy phosphate bonds.
Adenine
P
Ribose
P
P
Energy is released
when the high energy
phosphate bond
between the 2nd and 3rd
“P” is broken.
How does ATP store energy?
2. When a free phosphate group is attached onto
ADP, energy is stored in this bond to create ATP.
+
ADP
+ Energy
+P+
Energy
ATP
Using ATP Energy
For the cell to release and use the energy
in ATP, the bond between the 2nd and 3rd
phosphate groups must break; leaving
ADP and a free phosphate group.
Adenine
P
Ribose
ATP
ADP
P
P Energy
Released
P
ATP /ADP Cycle
A working muscle recycles over 10 million ATPs per second!!!
Energy
Stored Energy
ATP ATP
Bonds
Formed to
make ATP ADP
P
P
ATP /ADP
Cycle
ADPADP
Energy
ADP
Released
P
Energy
Released
to do work
Bonds Broken
PHOTOSYNTHESIS
What is photosynthesis?
• A chemical reaction in which plants
take the light energy from the sun and
convert it to chemical energy to make
their own food.
• Plants cells contain organelles called
CHLOROPLASTS
• Chloroplasts contain chlorophyll (green
color) which makes photosynthesis
possible.
• Carbon Dioxide enters the leaves
through the stomata (openings) and
combines with the stored energy in the
chloroplasts to make glucose.
• Glucose is moved through the phloem to
the rest of the plant.
Glucose is used as a food source for
the plants to carry out life processes.
Unused glucose is stored as a starch
or becomes part of the plant’s
tissue.
Chemical Equation-Photosynthesis
Reactants
6 CO2+ 6 H2O + sunlight
Products
6 O2 + C6H12O6
Carbon dioxide +water +sunlight (yields) oxygen + glucose
How does this relate to Cellular Respiration?
Once plants change the energy from
the sunlight into chemical energy
during photosynthesis, organisms
then have to change that chemical
energy into a form that is usable by
the organism’s cells during a process
called Cellular Respiration.
What is cellular respiration?
The release of chemical energy by
breaking down glucose and other
food molecules for use by the cells.
CELLULAR RESPIRATION
Reactants
Products
C6H12O6 + 6O2 --> 6CO2 + 6H2O + 36 ATP
(glucose + oxygen  carbon dioxide + water + energy)
-
• 2 forms: Aerobic (with O2 - oxygen)
Anaerobic (without O2- oxygen)
• Reaction is opposite of Photosynthesis
AEROBIC RESPIRATION takes place
in the presence of oxygen: (3 steps)
• Glycolysis- occurs in the cytoplasm
producing 2 ATPs and 2 pyruvates.
2. Krebs Cycle- takes place in the
mitochondria.
uses the 2 pyruvates from glycolysis
and releases 2 ATPs, 6CO2 and many
NADH & FADH2
3. Electron Transport- takes place in the
mitochondria.
Uses the NADH & FADH2 from Krebs and
produces 32 ATPs and 6H2O
ANAEROBIC RESPIRATION (no oxygen
present)
• Glycolysis- produces 2 ATP’s and 2 pyruvates
Alcoholic Fermentation in yeast
OR
Lactic Acid Fermentation in muscles