What is the relationship between
Photosynthesis and Cellular Respiration?
* atoms get rearranged
during these processes
Role of the Sun?
Provide energy (sun
light) which plants
use to create
glucose from water
and CO2
Role of
Glucose?
Broken down by
cells to create
(ATP)
Cellular Respiration
Overview
C6H12O6 + 6O2  6CO2 + 6H2O + 38 ATP
Cellular Respiration (process in which living things
convert the chemical potential energy stored in glucose
and other food into chemical potential energy in the
form of ATP). This occurs in the presence of oxygen
(aerobic process)
How do organisms harvest the
energy stored in foods?
Cellular Respiration: chemical
process that uses oxygen to
convert the chemical energy
stored in organic molecules into
another form of chemical energy
(ATP)
ATP (adenosine triphosphate) is a
usable form of chemical energy
Energy is stored in the bonds.
http://www.nutridesk.com.au/simple-sugars.phtml
Stored Chemical Energy in
food
Energy in food can be measured in calories or
Calories
calorie: amount of energy needed to raise 1g of
H20 by 1°C
A Calorie is what they use on food labels and is
actually a kilocalorie (1000 calories)
Chemical energy from food is converted into ATP
Exercise – Expended
Energy
Bicycling (Slowly) – 170 cal per hour
Bicycling (Racing) – 514
Dancing (Slow) – 202
Dancing (Fast) – 599
Running – 865
Swimming – 535
ATP provides energy for
cellular work.
ATP Packs Potential Energy!!!!
When a phosphate group is pulled away…energy
is released. This Energy is used for Cellular Work
Varying energy in the bonds
between phosphates
Mitochondria
Outer Membrane
Inner Membrane Space
Matrix
There are 3 Stages of
Cellular Respiration
1. Glycolysis
2. Krebs Cycle
3. Electron
Transport Chain
Location in Cell
Cytoplasm
Mitochondria
Mitochondria
What is Produced
2 Pyruvic Acid
4 ATP
4 CO2
2 ATP
H2O
34 ATP
Equation for Cellular Respiration
In cellular respiration, the atoms in glucose
and oxygen are rearranged, forming carbon
dioxide and water. The cell uses the energy
released to produce ATP.
Cellular Respiration converts energy in
food to energy in ATP
Stages Include… Glycolysis
What is produced?
The Krebs Cycle
ETC
Glycolysis (aka “splitting of sugar”)
Occurs in the cytoplasm
Glucose (6C) is broken down into 2 Pyruvic Acid (3C
molecules)
2 ATP molecules used, 4 ATP molecules produced
Net
Gain of
2 ATP
Occurs in the mitochondrial matrix
Pyruvic acid from glycolysis is used to produce NADH,
ATP, and FADH2
The NADH and FADH2 feed into the last step of cellular
respiration (the electron transport chain)
During Krebs cycle 2 ATP produced and carbon dioxide
produced
Electron Transport Chain
Occurs in the mitochondrial inner membrane
Uses the high energy electrons from glycolysis and
the Krebs cycle to convert ADP into ATP
High energy electrons are passed from one carrier to
the next
Oxygen serves as the final electron acceptor of the
electron transport chain (this is why oxygen is a
requirement of cellular respiration)
Oxygen and the Electron Transport Chain
As electrons
move down each
step in the chain,
a small amount
of energy is
released
The energy is
used to generate
ATP molecules
The totals
Cellular respiration (glycolysis, the Krebs cycle, and
electron transport chain) release about 36 molecules of
ATP per molecule of glucose.
Q: How efficient is cellular respiration?
A: converts about 36 percent of the total energy in
glucose into ATP
This is very efficient when compared to many human
inventions. For example the gasoline engine in a car is only
about 25% efficient.
Other food?
The diets of humans (and many other
organisms) that utilize cellular respiration
contain more than just glucose.
The cell can generate chemical energy in the
form of ATP from just about any source
To simplify things we focus on how it generates
ATP from glucose